THE SANITARY RELATIONS OF THE COAL-TAR COLORS LEFFMAN N Columbia ®nibersitp mtlieCitpoflmgork College of l^f)p&itian^ anb ^uvQtoni mhvavp I THE COAL-TAR COLORS WITH ESPECIAL REFERENCE TO THEIR INJURIOUS QUALITIES AND THE RESTRICTION OF THEIR USE A SANITARY AND MEDICO-LEGAL INVESTIGATION BY THEODORE WEYL WITH A PREFACE BY PROFESSOR SELL TRANSLATED WITH PERMISSION OF THE AUTHOR BY HENRY LEFFMANN, M.D., Ph.D. PROFESSOR OF CHEMISTRY IN THE WOMAn's MEDICAL COLLEGE OF PENNSYLVANIA, AND IN THE PENNSYLVANIA COLLEGE OF DENTAL SURGERY; PORT PHYSICIAN AT PHILADELPHIA PHILADELPHIA P. BLAKISTON, SON & CO IOI2 WALNUT STREET 1892 Copyright, 1892, by P. Blakiston, Son & Co. QP9'1 Press of Wm. f. Fell & Co.. 1220-24 Sansom St., philadelphia. TRANSLATOR'S PREFACE. Dr. Weyl's essay which I present in English dress, came into my possession a couple of years ago, and seemed to me to be of such practical value in an important department of hygiene, that I sought permission to translate it, a request which was kindly and promptly granted by the author. The widespread employ- ment of artificial colors in articles of food and household use and the absence of any comprehensive or even positive informa- tion in English as to their actions on the human system, will make the publication opportune. I undertook the translation over a year ago, but the close ap- plication to my college work and to my duties as Port Physician of the Port of Philadelphia, during the last fall and winter, has caused considerable delay. The introductory articles by Professor Sell and Dr. Weyl ren- der an elaborate preface unnecessary, but I may speak briefly of some of the features of the essay which will be more likely to suggest themselves to an American than to a European reader. The treatise will be found decidedly more technical than is usual in articles addressed to medical and sanitary circles in this country. I foresee that the array of formulae and reactions, especially the ring symbols of benzene and naphthalene, may deter many from perusal of the essay, yet the essential matter is so distinctly set forth that the chemical portion may be passed by those who are unable to comprehend it. I have deferred a little of the purely theoretical discussion to the appendix ; but, of course, I have not felt at liberty to omit any appreciable por- tion of the text. The original work contains numerous references by foot-note iii IV TRANSLATOR S PREFACE. to original authorities. Since these are accessible to few readers in this country, I have not thought it necessary to repeat the references in detail. For the more accurate and satisfactory representation, I have had engraved a hexagon matrix, types cast from which have been used in the ring symbols. It will be a source of gratification to the practical sanitarian to note the comparatively small proportion of really injurious colors, for even with some of those which produce marked toxic symptoms such large doses are required as to make it unlikely that serious results could occur by accident. The coloring power of these bodies is so high, as a rule, that almost inappreciable proportions are required for coloring articles of food, so that acute effects, at least, are impossible. A manufacturing confectioner of this city, for whom I make examinations of colors used by him, informs me that a yellow color sold as auramine, has such high tinc- torial power that one ounce will color two thousand pounds of candy to the highest yellow tint required in his business. It is obvious that the toxic dose of such a body would have to be very high to render it harmful in such use. A very interesting feature of the present essay is the summary of the existing legislation on the topic in the more progressive countries in Europe. We have here presented almost every method of reaching the end in view, viz., the protection of the public health without interfering with legitimate trade interests, from the practically absolute law-making power of Germany based on imperial will, to the constitutional system of England, with its reliance on the merits of each individual case. It is cer- tain that none of the plans is even approximately satisfactory, and the problem will be even more difficult of solution in the United States ; indeed, it seems to me to be unsolvable. Possi- bly the simplest and most satisfactory method would be to forbid absolutely the use of any artificial color in certain food articles with which such coloration is likely to deceive the user as to quality or condition, and to require in all other cases that the name and amount of color should be placed on the package. TRANSLATOR S PREFACE-. V Thus, the addition of color to milk, butter, cheese, bread, cake, noodles, and wine should be absolutely forbidden, since the object of such addition will be always to deceive the buyer as to the quality or composition of the material, but candies, confec- tions and toys are known to be colored, and either the use of certain colors and none others should be permitted, or the color used should be required to be indicated on the package. In this connection it is well to note that the most serious reported cases of poisoning from colored foods have been those in which mineral colors were used. The knowledge that irritative or pathogenic microbes are apt to be present in any material which has been exposed to air, leads us to regard as of doubtful value all those experiments in which endermic or hypodermic application of the colors was employed without antiseptic precautions, since the results are complicated by such infection. This is doubtless the case with the observation of Tardieu, on the poisonous nature of corallin. The preparation made from the stockings was more poisonous than the original dye, because it was infected, as would naturally be the case, with more virulent organisms. In the preparation of this translation I have endeavored to be strictly accurate, and yet to avoid the employment of forms of expression not recognized as good English. Some slips will, however, certainly occur, and further, I cannot hope to escape some errors in transcription or composition. For all such I ex- press my regrets in advance. I again express my thanks to Dr. Weyl for the permission to translate the essay, and hope that it may assist in diffusing accu- rate information on a topic of much practical sanitary moment. H. L. yij Walnut St., Philadelphia, Augtcst, j8g2. PREFACE. Most civilized communities have considered it advisable to regulate the use of colors in food preparations and other house- hold articles. It appeared to me, however, after much investi- gation, that the experimental basis for such enactments, notably as concerns coal-tar colors, is insufficient, indeed, in some re- spects, wholly wanting. The present contribution is intended to include a synopsis of such information as was already attain- able, but more particularly to present new material which may have valuable bearing on the framing of restrictive laws. Prac- tical application, therefore, is the especial purpose of this re- search. The method of presentation must be adapted to the fact that the essay is addressed to both physicians and chemists. Physicians will desire some general views of the chemistry of the colors, since this part of the subject is as much neglected by them as the principles of experimental pathology and toxicology are neglected by chemists. I trust I have done justice to each class, in that I have not been too medical for the chemist, nor too chemical for the physician. In exploring along the contiguous territory of two sciences it is not easy to escape such mistakes. The collection of enactments and regulations, as far as accessible to me, will be found useful. The names and properties of the colors are given in some detail, while the method of preparation is but briefly outlined. That such investigations as the present are rather a source of satisfaction than of anxiety to the color- making industry does not need argument. I offer, therefore, to my professional brethren far and near, this first contribution, not without asking for myself some indulgent consideration of it, by reason of the difficulties attending the task. My thanks are due to C. Liebermann, E. Salkowsky, and N. Zuntz, for affording me the facilities of the laboratories under their charge. W. vii CONTENTS. VAGR History and Gkneral Apfltcations, 17-22 Preparation — Classification — Nomenclature — Commercial forms — Uses — Dyeing, Mordanting and Printing — Fastness — Detec- tion. Poisonous Colors, 21-31 Non-Poisonous Colors, 31 Laws Regulating the Use of Poisonous Colors, 31-34 Appendix — Legal Enactments Co.xcerning the Use of Colors IN THE Preparation of Food, 35-53 Germany — England — France — Italy — Austro-Hungary. Scope of the Investigation, 53 Methods, 54-60 Selection of Colors — Selection of Animals — Manner of Adminis- tration — Diagnosis. Nitroso-Colors, ■ . . . 61-66 Dinitroresorcinol — Naphthol Green B. NITRO-COLORS, 66-96 Picric Acid — Saffron-substitute — Mariius' Yellow — Naphthol Yellow S — Brilliant Yellow — Aurantia — Other Nitro-colors. Azo-CoLORs — Chemical Considerations, 96-114 - Historical — Production — Materials Employed, Decompositions and Transformations — Solubility, Color, Deportment with Fibres — Typical Reactions — Commercial and Scientific Des- ignations — Classification. Observations on Animals, 114-134 Records from other Experimenters — Weyl's Researches — Bis- marck Brown — Soudan I — Metanitrazotin — Paranitrazotin — Orange II — Ponceau 4 G B — Archil-substitute — Chrysoidin — Diphenylamine Orange — Metanil Yellow — Azarin S. ix X CONTENTS. PAGE DiSAZO-COLORS, 134-137 Fast Brown S— Wool Black— Naphthol Black P— Congo Red— Azo-Blue — Chrysamin R. Conclusions, 147 Appendix, 147-15 1 Formation of Dve-stufts — Note. INTRODUCTION. Thanks to the co-operation of theory and practice, the coal-tar- color industry of Germany has conquered the world, and in- asmuch as new and improved methods are continually being devised, will be able to maintain its pre-eminent position. As a result of this steady work, we find thp list of colors constantly increased by new products which enter into competition with those already in the market. Consumption must stand in sgme relation to production if satisfactory results are to be obtained, and trade interests stim- ulate endeavors to secure new uses for the growing supply. It is not surprising, therefore, that the applicability of these colors to food preparations has suggested itself. Whether these bodies are adapted to such uses, and whether they may be constantly taken into the system, even in small doses, without disturbing the organ- ism, are questions of great moment in public hygiene; questions which hitherto could not be answered, for want of satisfactory information. For this reason the present essay of Dr. Weyl is especially welcome. The author has made a valuable contribution toward determin- ing the physiological relations of those colors applicable to foods, and his work does him much credit, even though, as he points out, experiments on animals cannot be unreservedly applied to human beings. An especial recommendation of the work is that the author has sought to discover the relation between chemical composi- tion and physiological action, an undertaking which, carried out fully, may make it possible that the expert will be enabled to indicate the action of each group instead of that of individual colors. xi Xll INTRODUCTION. Assured that the author himself will further pursue the path he has opened, a hope must also be expressed that others may soon find it opportune to assist in the difficult work of this investi- gation. Our thanks are due to Dr. Weyl, not only for presenting to us a conspectus of the most interesting features of each group, but also, for a summary of the existing legislation of these matters, in the principal civilized States of Europe. It is to be hoped that the work will find favorable reception in all circles which are interested in these questions. S. Berlin, October, i88S. THE COAL-TAR COLORS. GENERAL PART. HISTORY AND GENERAL APPLICATIONS. Preparation. — When coal-tar, the source of the coal-tar colors, is subjected to fractional distillation, products, technically known as raw materials, are obtained,, among which are benzene, toluene, xylene, naphthalene, anthracene, phenol and cresol. The color-maker transforms these into intermediate products, and then into colors. For example, from benzene and toluene, are obtained by the action of nitric acid (nitration) the intermediate products, nitrobenzene and nitrotoluene. By reduction, aniline (amidobenzene) and toluidine are formed. By oxidation of a mixture of aniline and toluidine, a dye-stuff, rosaniline, is pro- duced, which belongs to the aniline colors proper, or triphenyl- methane derivatives. So also, naphthalene — raw material — yields naphthol — intermediate product — which united with diazobenzene chloride — the latter obtained from aniline by the action of nitrous acid — gives rise to an azo-color. Phthalic acid (intermediate product) united with another intermediate product, resorcinol, forms the dye called fluorescein, which belongs to the phthaleins. The best known of these is eosin — tetrabromfluo- rescein. The highly important dye known as alizarin is derived from anthraquinone, the latter being obtained from anthracene. Other classes of colors have also been recognized, such as safran- ins, indamines, indophenols, etc. Classification. — The various colors were at first merely designated as red, green, yellow, etc., coal-tar colors. Later 2 17 1 8 THE COAL-TAR COLORS. they were named according to source, as aniline, phenol, and naphthol colors. Subsequent research has elucidated the atomic structure, and rendered possible a classification in natural groups based on the chemical constitution. The following are some of the most important groups, with examples of each : I. Nitroso-colors. Naphthol green B, solid green. II. Nitro-colors. Picric acid, Martins' yellow, naphthol yellow S, aurantia. III. Azo-colors. Aniline yellow, Bismarck brown, Biebrich scarlet, fast yellow, fast red, tropaeolin. IV. Triphenylmethane colors (anilines, properly so called), fuchsin, malachite green, Victoria green. V. Rosolic acid colors. Corallin, rosolic acid. VI. Phthalein colors. Eosin, erythrosin. VII. Anthracene colors. Alizarin, alizarin orange. VIII. Indigo colors. Indigo. IX. Quinoline colors. Quinoline yellow, cyanine, chrys- aniline. X. Indophenol colors. Methylene blue. XI. Azine colors. Safranin, magdala red. XII. Aniline black. The characteristics of these groups will be given in the Special Part. These dyes deport themselves in part as acids (acid dyes), partly as bases (basic dyes), and in part as indifferent bodies (neutral dyes). Indigo belongs to the last group. Among the acid colors are the nitrated and sulphonated bodies, such as pic- ric acid, oranges, ponceaux, and all nitro-colors. Basic colors are salt-like combinations of color bases with acids, e. g., fuchsin and methylene blue, and are precipitated by tannin or picric acid in the presence of sodium acetate. Acid colors are mostly in- soluble in water, but dissolve in alkalies. Nomenclature. — The trade names of the coal-tar colors are mostly fanciful, since the scientific titles are cumbersome and difficult to remember. Thus, tetramethylthionine hydrochloride is called methylene blue ; aurantia is hexanitrodiphenylamine ; wool-black is the sodium salt of sulphazosulphobenzeneparazo- HISTORY AND GENERAL APPLICATIONS. I9 tolyl-/?-amidonaphthalene. A color may have various names : crocein orange, ponceaux 4 GB, and brilliant orange, are iden- tical. The terms Bismarck brown, phenylene brown, Manches- ter brown, and canelle, refer to the same color. Different colors are often designated by the same name, especially with a view of substituting a cheap for a costly product. In this way, according to Kertesz, the low-priced Martius' yellow is called naphthol yellow S, although the latter name belongs to a more expensive preparation. Finally, mixtures of familiar colors necessary to produce peculiar tints are frequently sold under new names, with deceptive intent. Cardinal, for example, is a mixture of chrysoidin and fuchsin. Commercial Forms. — Coal-tar colors are offered by dealers either in the form of paste or powder. They may be soluble in water or alcohol, or both. Insoluble colors find obviously but limited application, but it. has become possible by special treat- ment to render them soluble. This takes place, for instance, by the action of sulphuric acid (sulphonation), or when azo-colors are converted into bisulphites. The commercial colors are often mixed with dextrin, sodium sulphate, sodium carbonate, or am- monium chloride. This so-called coupage (reduction) is rarely done with fraudulent intent, but generally for one of the follow- ing reasons : — The method of preparing a color does not always yield the same tint ; the product may be now lighter, now darker, perhaps due to slight differences in the temperature during the process, or in the subsequent drying. Since, however, the dyer requires that a certain color shall yield a definite shade when a given pro- portion is employed on the fabric, the manufacturer must reduce the strength of the more highly-colored product. Furthermore, the dyer is accustomed to employ considerable weight of the materials, since it involves less variation from loss or error when, for example, 2000 to 2050 grams are employed, than when only from 100 to no are to be weighed out. Hence the manufacturer reduces considerably the strength of the dyes of high coloring power. Finally, the prices may be made lower for the more 20 THE COAL-TAR COLORS. extensively diluted articles. In general, the coal-tar color-maker strives to furnish pure articles, and we must not forget that small admixtures of foreign substances are unavoidable. The traces of salt, lime, etc., are without significance. Injurious impurities, such as arsenicum, lead, etc., are scarcely found at the present time in coal-tar colors of German manufacture. Uses. — The natural colors formerly employed by the dyer, have gradually given way, in great part, to the more convenient and cheaper artificial products. There are hardly any dyed ma- terials now in the market in which coal-tar colors are not used. Of course, their prime use is in dyeing the textiles, silk, wool, cotton, hemp, etc., but they are largely used to color various other animal and vegetable products, among which may be men- tioned, hair, feathers, leather, bone, ivory, wood, straw, leaves, flowers, paper, soap, and ink. Finally, foods, such as butter, cheese, noodles, confectionery, wines and liquors, are colored by these bodies. The staining of microscopical preparations by means of coal-tar colors has been of great value in scientific investigations. Dyes that are absorbed directly by the fibre are called sub- staiitive dyes; among these are fuchsin, safranin, and Bismarck brown. Those that require the fibre to be impregnated with some substance are known as adjective dyes. The material used is called the mordant, and its action is due to the formation of an insoluble compound between the fabric and the color. When a metallic salt is used as a mordant, the insoluble compound is called a lake. Among the familiar mordants are lead, copper, and chromic acetates, alum, zinc chloride, and tartar emetic. Turkey-red oil — produced by the action of sulphuric acid on castor oil — tannin, starch, and white of ^gg are frequently used. Mordants are important in the dyeing of vegetable fibres, notably cotton. Recently, however, some azo-colors belonging to the Congo-red group have been obtained, which give fast colors on cotton without mordanting. Dyeing, Mordanting, Printing. — The dyeing of textiles depends, as is generally known, upon the production of a chem- HISTORY AND GENERAL APPLICATIONS. 21 ical combination between the color and the fibre. A given color does not necessarily color all fibres. Cotton is not dyed by alkali blue, naphthol yellow, or acid magenta, while silk is easily colored by them. Picric acid dyes animal fibres readily, but can be attached to vegetable fibres only by the aid of a mordant. Textiles can be dyed either in the yarn or in the piece. For printed goods the procedure is as follows : The color is mixed with starch paste, tragacanth, or some other suitable thickening material, the mordant being often incorpor- ated at the same time. The mixture is imprinted on the goods by means of rollers, and the tissue subsequently steamed, by which the insoluble compound between the fabric and dye is formed ; this then will remain after rinsing and soaping. Pat- terns can be produced upon cloth in two ways. Either the proper portions of the tissue are protected by the imprinting of materials which prevent the dye from adhering, which method is known as reservage, or the entire cloth is dyed, and then cer- tain portions are removed by the application of some decolor- izing material, this latter method being known as enlevage. These methods are especially applicable in calico printing. Fastness. — A color is said to be *'fast" when it is un- affected by various external influences. Obviously, this quality concerns especially the dyed colors. The dyer recognizes colors as fast to light, to washing, to moisture, to scouring, to the action of soap, acids, and alkalies. Nearly every organic color is more or less rapidly bleached by light. Wool, for instance, dyed with picric acid acquires, after a few days' exposure to light, a brown- ish tint, while alizarin is one of the fastest of colors. Alizarin blue and Congo red are almost perfectly fast to washing, when on cotton, while eosin is easily removed by the same means. Fastness to scouring concerns such articles as require treatment with alkaline solution, e. g., stale urine mixed with ammonium carbonate. By such treatment, oil and gelatin are removed, and a felting of the fibres brought about. Acid green is toler- ably fast to scouring ; still better are alizarin blue and rosaniline blue. 2 2 THE COAL-TAR COLORS. Detection. — The recognition of the coal-tar colors on fabrics and in food offers so many difficulties, in many cases at least, that even expert chemists are not always able to get satisfactory results. The difficulty originates partly in the fact that there are a great number of these colors, partly because the amount of color used is, as a rule, owing to the high tinctorial power, very small. It is, therefore, best in such investigations to employ consider- able amounts of the material to be tested. For methods of recognizing the various colors, see the Special Part of this work and the authorities cited. POISONOUS COLORS. Non-poisonous coal-tar colors may be rendered injurious by admixture with poisonous substances. Medical literature fur- nishes us with an imposing array of cases of poisoning by ^^ani- line colors," in most of which fuchsin or similar colors are concerned. When the manufacture of aniline colors was first introduced, toward the close of the sixth decade of this century, the poisonous quality of these bodies was unquestioned, in view of their derivation from so poisonous a body as aniline. It was natural to assume that the deleterious properties of the parent substance should be transmitted to the derivatives. The first ani- line color manufactured on the large scale was mauve'in, which Perkins prepared in 1858. Fuchsin, discovered by A. W. Hof- mann in 1858, was the second color, and was first made on a com- mercial scale by Verguin, in Lyons, in 1859. ^^ ^^^^ ^^^^ ^ ^^^^ of the color was worth about 1200 marks; in 1866, 50 marks. The first investigations into the effect of fuchsin and its congeners upon the animal organism seem to have been made by Sonnen- kalb. The colors examined, aniline red and aniline blue on silk, and fuchsin, were found to be non-poisonous. Sonnenkalb, how- ever, pointed out that they might become poisonous by reason of impurities such asarsenicum and mercury, which were employed in the process of manufacture. To such impurity he ascribed the case first reported by Friedrich and subsequently so frequently POISONOUS COLORS. 23 quoted, of apparent poisoning in a young man who was for two months engaged in packing anihne colors, Lyons blue, light blue, and fuchsin Nos. i and 2. I doubt if this case was due at all to the work in which the patient was engaged. Sonnenkalb confirmed the correctness of the general opinion as to the poisonous nature of arsenical fuchsin. In this category belongs also the case of poisoning by arsenical fuchsin observed by Clemens, in which a girl engaged in embroidery work per- mitted the red silk thread to glide constantly over the same point on the finger until a narrow incised wound in the skin was de- veloped, from which arose phlegmonous inflammation, which spread over the hand and forearm. In consequence of the fact that, about the year i860, it became known that many French wines were being extensively colored with fuchsin, the French investigators were especially active in studying the effects of this dye on the animal organism. In the experiments of Clouet and Bergeron, dogs were found to bear without injury daily doses of 20 grams of fuchsin, and a man took in the course of a week a total of 3.5 grams without noting any inconvenience. Clouet and Bergeron therefore regarded fuchsin as harmless. It is uncertain whether the fuchsin em- ployed by Feltz and Ritter,-'"^ which gave rise to diarrhoea and albuminuria, was pure. As is known, Coupler f discovered a method of making fuchsin without the use of arsenic acid or mercuric oxide, by employing nitrobenzene, which, although very poisonous, is volatile and can be easily driven off. Grandhomme fed two rabbits for several weeks with fuschin prepared by the Coupier-Briining method, administering daily 0.5 gram with 50 grams of barley. The animals remained in good health and the urine contained no *In Cazeneuve's work, p. 43, is a review of what seems to be rather an inexpert research by Poincare oai the effect of various coal-tar colors on the animal organism. f The Coupier-Briining fuchsin was for some time called "nitrobenzene fuchsin." 24 THE COAL-TAR COLORS. albumin. After an interval, 15 grams of fuchsin and 15 grams of barley were mixed and fed during two weeks. No disturbance in the condition of the animals was noted. Subcutaneous injection of a one per cent, solution once or twice daily had also no effect. Similarly, a hen, which had eaten for three weeks oats colored with fuchsin, was in good health. In entire accord with all in- formation concerning the harmlessness of pure fuschin are Grand - homme's interesting observations among the workmen of the Hochst Color Works. In the fuchsin department, 52 workmen were employed, of whom — 6 had been working there from 3 to 4 years. 6 " " " 4 '< 6 " II " " " 6 " 10 " 5 " " "II " 18 " None of these men suffered either from diarrhoea, colic, or disturbance of the urinary secretion, although daily breaching the fuchsin dust. Tests of the urine, made on Saturday evening after the entire week's work, showed absence of albumin. Fur- ther, investigations as to the effect of pure fuschin in cases of heart and kidney disease showed the entire harmlessness when taken into the stomach. Finally, it is now and then asserted that skin diseases have been brought about by garments dyed with fuchsin and similar colors. In the notice of Bruce's case — cutaneous eruption fol- lowing the wearing of a red-dyed chest- protector — no account is given of any chemical examination of the color. The case of skin disease reported by Viand-Grand-Marais, of Nantes, which appeared during the wearing of an amaranthine and violet-colored woolen shirt, was ascribed to a dye which, according to the authority, showed by Marsh's test only small amounts of arsenic. The above facts justify the view that pure fuchsin is non- poisonous : the poisonous action of the commercial color is due 10 arsenical compounds. According to Grandhomme, aniline blue, aniline violet (dahlia), and malachite green are also non- poisonous. POISONOUS COLORS. 25 A similar statement seems to apply to corallin. Tardieu re- garded this as poisonous. It is produced by heating phenol with oxalic and sulphuric acids " to 120-130° C." The crude melt, which presents itself as a dark red resinous mass with metallic lustre, is known as yellow corallin. The pure color obtained from yellow corallin is called aurin. On account of their fugitive character, red and yellow corallins are not much used in dyeing, but are employed in the printing of calicoes and woolens. Red corallin, also known as pseonin, is produced by treatment with ammonium hydroxide under pressure. Tardieu, has reported eight cases in which the wearing of stockings dyed with corallin was attended by the development of a vesicu- lar eruption. He undertook, in conjunction with Roussin, two series of experiments. In the first, red corallin obtained from Persioz, was injected into the stomach. The majority of the animals died. In the second series, Tardieu used the ex- tract from the suspected stockings. The animals died more quickly than in the first series. Weickert pointed out that the corallin was administered in alcoholic solution. The post- mortem indicated alcoholic poisoning, but it does not appear why the extract from the stockings was the more poisonous. Moreover, Weickert's trustworthy researches have proved the entire harmlessness of the red corallin made by WiiVtz of Lieb- enau, whether administered endemically, hypodermically, or by the stomach. The men engaged in preparing and putting up the corallin in the Wurtz factory were in good health, although the skin of the hands was intensely colored. From these facts it appears that pure corallin is non-poisonous. In all proba- bility, the eruption that attended the wearing of the stockings was due to an arsenical mordant. The German law, relating to the use of injurious colors, etc., restricts the use of arsenical mordants to such proportions as will give not more than 0.002 gram to 100 sq. cm. of the finished goods. It is known that the workmen in color-printing departments are most likely to be affected. I may note some observations made in the extensive 26 THE COAL-TAR COLORS. cotton-spinning and printing establishment at Zawiercie, for- merly operated by A. & B. Ginsberg, for the report of which I am indebted to Mr. Ginsberg, of Berlin. Workmen dealing with sodium arsenate and other arsenical preparations, especially in the damp rooms of the dye-house, in which they worked all day in wet clothes, suffered from swelling of the hands, feet, and testicles. Dermatitis and a pock-like eruption occurred which necessitated removal of the patients to the hospital. In conse- quence, the use of arsenical mordants was discontinued and without disadvantage to the operation of the establishment. Landrin, Babaut, Bourgongnon, Chevreul, and P. Guyot agree with Weickert. However, it seems, as Sell has pointed out, commercial corallin occasionally contains phenol. For this reason, the German law of July 5th, 1887, places corallin among the prohibited colors. According to Zulkowsky, rosolic acid (methyl-aurin) is obtained by the oxidation of cresol (mtthyl- phenol) by arsenic acid, in the presence of sulphuric acid. If this method should be actually used, as to which I have no knowledge, commercial rosolic acid might contain arsenicum. In this connection, the remarkable case of hyperidrosis, re- ported by Grandhomme, should be mentioned. In the Hochst dye-works, at various times from 1874 to 1882, many workmen, in all 47, most of whom worked in the eosin department, were affected as follows : After a varying period, the men were seized with pain in the finger tips and ball of the thumb, and in three cases abscesses were formed. In every case the perspiration was so abundant that drops fell from the depending hands. The general healtli did not seem to be disturbed and the per- spiration showed no abnormality either in odor or appearance. Recovery took place in about sixteen days. The cause of the affection is not definitely known. Possibly, it arises from some, as yet unknown, admixture in the material, possibly, from the use of strong chlorated lime solution for cleansing the hands. At any rate, the cases have become less frequent since the use of such strong solutions has been interdicted. The eosin itself POISONOUS COLORS. 27 cannot be the cause, since those engaged in packing it are in no wise affected. Dr. P. Seidler has kindly communicated to me the note of a case of hyperidrosis which affected a chemist of his acquaintance! The patient had been in the dye-works of Bayer & Co., in Elberfeld, and had used very strong chlorated lime solution for cleaning his hands. Grandhomme's view as to the cause of the malady is, according to this, confirmed. I am now investigating this subject. A critical review of the existing literature shows that trust- worthy evidence of poisoning by pure aniline colors is not at hand.* In all probability, the cases in which the color has been sus- pected, have arisen from admixture with arsenical compounds, or the use of arsenical mordants. The following additional con- sideration confirms the view as to the harmlessness of pure anilines. The general condition of the health of those engaged in coal- tar color factories weighs against the harmfulness of these colors. If the aniline colors, and artificial colors in general, were as poisonous as is often gratuitously assumed, those engaged for long periods in the manufacturing or handling the same, or otherwise brought in close contact, ought to be frequently affec- ted injuriously. Of course, the products and by-products of the processes bring about, frequently, both acute and chronic poison- ing. It would, indeed, be surprising if those who are engaged in the manufacture of benzene, nitro-benzene and similar bodies, should not be more affected by them than those who may have but seldom, perhaps only once, even seen such materials as specimens in a cabinet. Nevertheless, Grandhomme states that in the extensive factory at H6chst-on-the-Main the proportion of sick among those who are concerned in manufacture of the * For a small number of cases of poisoning by picric acid, see the Special Part. 28 THE COAL-TAR COLORS. raw material, is insignificant. The following tables are from Grandhomme's work : — Department of No. OF Men. Illness Due to THE Work. Remarks. Factory. Number. Per Cent. Nitrobenzene, . . . Aniline, Anthracene, . . . 96 116 2 5 18 5-2 15.5 0.0 r No nitrobenzene \ poisoning. Aniline poisoning. Still more favorable are the figures relating to those who work at the actual manufacture of the aniline colors : — Illness Due to Work. No. OF Workmen. No. of Years. Remarks. • Department. No. of Cases. Percentage. Rosaniline, . 2 2 Fuchsin, . . 396 9 31 7.8 Skin affections. Blue, . . . 120 4 I 0.83 Aniline poisoning. Dahlia, . , 88 4 0.0 Green, . . . 84 4 0.0 Eosin (prin- ~l cipally), J 112 4 27 24.1 Hyperidrosis. Even this small percentage has been reduced materially by the introduction of hygienic measures, as the following table shows : — Years. No. of Workmen. Illness. Remarks. No. of Cases. Percentage 1879 1880 1881 1882 325 447 508 500 13 18 17 7 4 4 3-3 1-4 Aniline poisoning. (( (( POISONOUS COLORS. 29 The hygienic provision consisted in better ve'ntilation of the work-rooms, and the regulation that the workmen should be allowed more frequently to go into the open air, also prohibition of the employment of chlorated lime solution. If now we determine the percentage of sickness among the workmen in branches of industry in which actual poisons are used, we find that the statistics of the aniline industry compare very favorably. The numbers for the workers in aniline have been determined from the following statistics given by Grandhomme : — Diseases. Infectious diseases, Diseases of nutriiion, ..... " " circulatory system, . " " nervous " " " special senses, ... . " " respiratory apparatus, " " digestive " " due to occupation, . . . Not otherwise classified, .... 330 Workers in Alizarine. Workers in Aniline. 7 35 77 172 5 12 16 56 28 63 89 288 103 339 1060 Therefore, a total of 330 plus 1060 equals 1390 internal affec- tions. Of these 88 were cases of poisoning from occupation, which equals 6.;^ per cent. Occupation. Percentage of Cases OF Disease. Form of Affection, Etc. Gilders, Zinc white workers, . . . Phosphorus makers, . . . Mercury miners, .... 2-3 3-4 Phosphorus poisoning. Mercury " 30 THE COAL-TAR COLORS. Occupation. Aniline makers, . . . Hat makers, Glaziers, Blue color makers, . . Artificial flower makers, Arsenicum miners, . . Sweinfurth green makers, Sugar of lead makers, . Potters, .... Tin workers. Type founders, . Tobacco workers. Silver miners, White lead makers. Percentage of Cases OF DiSF.ASE. 6.3 7-5 lO.O 12.5 15 20 20 21 25 35 35 15 (male). 45 (female). 58 68 FoBM OF Affection, etc. Aniline poisoning and hy- peridrosis, probably due to arsenicum. Mercury poisoning. Lead " Arsenical " Lead " it (I J Lead and arsenical \ poisoning. . Lead poisoning. Nicotine poisoning. Lead " Dr. Coster thus expresses himself in regard to the general health of the workmen in aniline works : — " We are justified in saying that work in aniline-color fac- tories, usually regarded as very injurious to health, does not, in any way, involve greater dangers than belong to working in factories in general, apart from such acute effects as result from sheer carelessness." From the above facts it follows that the poisonous qualities of the aniline colors are not manifested among those who manufac- ture them. It remains to mention a (ew colors known to be poisonous. The injurious character of picric acid and its salts has long been known. Cazeneuve and Lepine pointed out the poisonous LAWS REGULATING THE USE OF POISONOUS COLORS. 3 1 nature of Martins' yellow, safranin, and methylene blue :* and I have shown the same for dinitrocresol (saffron-substitute). f NON-POISONOUS COLORS. According to Cazeneuve and Lepine's experiments the following are not poisonous to human beings and dogs: Naphthol yellow S, and certain azo-colors employed for the coloring of wine : viz., orange, ponceau R, purple, and solid yellow. According to Grandhomme, rabbits bear without injury, fuchsin free from arsenic, and other triphenylmethane derivatives (aniline colors) eosin, erythrosin and orange. Butter yellow (dimethylamidoazobenzene) produces no disturbance in rabbits. The toxic action of aurantia is in dispute, concerning which, see the Special Part. LAWS REGULATING THE USE OF POISONOUS COLORS. In spite of the facts recorded in the preceding pages, which show that the danger of poisoning from the aniline colors has been much overrated, at least as far as our present knowledge extends, most civilized countries have deemed it necessary to enact laws against the employment of the common colors in the preparation of food, drink and household articles generally. These regulations, as far as obtainable by me, are presented as an appendix to this chapter.:]: All these various legal provisions have the same purpose: to prevent the adulteration of food, * Confirmed by P. Ehrlich, by information kindly communicated verbally. Compare also the exhaustive investigation on "Neurotropic" colors by the same authority, Therap. Monafsh., March, 1887. t See Zeit. f. angew. Chem. 1888, No. 12, for confirmation of my results by Gerlach. X I gladly avail myself of the opportunity to express my sincere thanks to Messrs.^ Carnelutti, of Milan, Otto Hehner, of England, and E. Ludvvig, of Vienna, for furnishing me with the text of the laws concerning their respective countries. 32 THE COAL-TAR COLORS. drink, and household articles. The method by which this is reached is threefold. Germany, France, and Austria, enumerate the harmful colors which are not allowed to be used. England places a penalty for the adulteration without stating what colors are to be con- sidered injurious. Italy, coincides with England in the form of the law, but provides that the determination of the injurious articles shall rest on the judgment of experts appointed by the Secretary of the Interior. A justification for these laws, of course, cannot be denied. A little consideration will show that the practicability of the legal provisions is as unequal as the sense of equity and justice which finds expression in them. The English law imposes a fine of fifty pounds sterling upon every one who mixes or colors food with any injurious ingredient. Subsequent offenses may be punished with imprisonment, up to six months. This law seems to give satisfaction in England. At least Mr. Otto Hehner writes me, under date of July 3d, of this year: ^'So far as I know, no case has come unde* this paragraph of the law of 1873, since its enactment. Aniline colors, as long as they are not strongly arsenical, are not re- garded as injurious. Nor do any special provisions exist here (/. e. in England) concerning the use of poisonous colors in the carpet-weaving or calico-printing industries. The force of public opinion and publicity is so great that no one would dare to employ poisonous colors." Unfortunately, here in Germany, we cannot rely upon the force of public opinion, nor on publicity, in matters concerning the adulteration of food. We cannot regard a law as either cor- rect or practical which punishes the adulteration of food without enumerating those ingredients which are to be regarded as harm- ful. The Austrian law seems to be the simplest : The various provisions enumerate those colors which may be used in food, and punish every dealer who has in his factory or store any other colors, no matter what name these bear. The regulation of May, 1866, (see Appendix) is indeed difficult of execution. How can a confectioner be held responsible for the employment of a LAWS REGULATING THE USE OF POISONOUS COLORS. ^^ color, the harmfulness of which was not known at the time of its application ? On the other hand, no objection can be brought against the regulations issued on May ist, 1886, nor those noted subsequently, intended to meet a special purpose. The regula- tion forbids the employment of any color prepared by chemical treatment of aniline or other coal-tar products. This enact- ment takes away the least doubt that the Government pro- hibits the use of all coal-tar colors for the purpose under con- sideration. The basis of the prohibition is entirely in accord- ance with the spirit of the law. It is the sense of the declara- tion that there are many coal-tar colors in commerce the action of which on the human organism is unknown and the adulteration to which they are liable suspicious. Such articles should not be employed in the preparation of food and drink. Austrian regulations are the most radical in this field. It is to be assumed that the principle which has as yet found application only through executive action will take the form of enactment. Less severe than the Austrian law are those of France and Ger- many. The German law forbids the employment of certain enumerated colors and permits, therefore, the use of those not mentioned. In France the injurious and consequently forbidden colors are listed as well as those which are harmless and, there- fore, permitted.^ Without doubt, both these laws, which repre- sent the results of toxicological and chemical research up to a certain time, have been of much service to public hygiene. As regards the effects of mineral colors on the human organism, we are sufficiently informed. The near future will not bring forth material changes in regard to these, but it is otherwise with the organic colors. Chemical technology moves by giant strides : new colors are brought into the market, and no inquiry is insti- tuted as to the effect on the human body. If the new color is more beautiful than its predecessor, or cheaper, the tradesmen * The regulations by the magistrates of Milan, advance sheets of which were sent me by the courtesy of Dr. Carnelutti, permit the employment of certain definite — that is to say enumerated — coal-tar colors. 3 34 THE COAL-TAR COLORS. throw the older color to one side. This is not forbidden by law. The dealer is allowed the employment of any color not men- tioned in the regulations, even though it may have been subse- quently proved injurious. A characteristic illustration of this point may be found in the proclamation emanating from the Chamber of Commerce of Sonneberg, This body recommends for the preparation of children's toys, three colors, the poisonous character of which I can demonstrate. These are Martins' yel- low, safranin, and Bismarck brown. Of course, the Chamber of Commerce could only abide by the law, and this did not allude to the above named materials. The law maker, however, is not to blame, for the facts to which I refer were not known at the time the law was prepared. Obviously, some amendment must be brought about. This can be done either by forbidding the use of all coal-tar colors in the preparation of food and drink, or by following the plan of the Italian law and providing for periodical investigations by a commission of chemists and physi- cians, to determine what are, and what are not, appropriate colors for such uses. Upon the reports of such commission, the legisla- ture will regulate the use. Should the use of every one of the colors be forbidden, as has been done by the German government in the case of the coloring of wine, the problem is solved in the simplest manner. By this means we would bring about the same condition that prevails in Austria. Many serious difficulties beset the carrying out of the second plan. A commission can only act to advantage when it subjects colors to investigation before they come into commercial use. Undoubtedly the whole matter must undergo a revision, prob- ably in the shape of a general poison law affecting the entire Empire. I will return to a discussion of this topic in a later sec- tion of this treatise. APPENDIX. LEGAL ENACTMENTS CONCERNING THE USE OF COLORS IN THE PREPARATION OF FOOD. Germany. I. Laws concerning the use of unwholesome colors in the manufacture of food, drink, and other articles. July 5, 1887. We, William, by the Grace of God, Emperor of Germany, King of Prussia, etc., order, in the name of the State, in accord- ance with the approval of the Federal Council and the Imperial Diet, as follows : — 1. Unwholesome colors are not permitted to be used in the preparation of articles of food and drink which are exposed for sale. Colors which contain antimony, arsenicum, barium, lead, cadmium, chromium, copper, mercury, uranium, zinc, tin, gam- boge, corallin, picric acid, are unwholesome in the sense of this Act. The Chancellor of the Empire is empowered to set forth exact methods for determining the presence of arsenicum and tin. 2. Vessels, wrappers, or covers dyed with colors referred to in § I are not to be used for holding or protecting articles of food or drink. The present regulation does not apply to the use of the fol- lowing : Barium sulphate (heavy spar, fixed white), barium col- ors free from barium carbonate, chrome green, copper, zinc, tin and their alloys when applied as metallic colors, cinnabar, tin oxide, tin sulphide in the form of mosaic gold, all vitrified colors in glass, glazes, or enamels, and colors on the outside of water-tight vessels. 3. In the preparation of cosmetics (materials intended for 35 36 THE COAL-TAR COLORS. the cleaning, care, or tinting of the skin, hair, or cavity of the mouth) put up for sale, the materials enumerated in § i must not be used. This rule does not apply to the use of barium sul- phate (heavy spar, fixed white), cadmium sulphide, chromium oxide, cinnabar, zinc white, tin oxide, tin sulphide, nor to cop- per, tin, zinc, and their alloys in powdered form. 4. In the manufacture of toys (including picture-cards, pic- ture-books, and water-colors, flower-pot covers, and artificial Christmas trees), the materials forbidden in § i are not to be used. This regulation does not apply to the articles ex- cepted in § 2, nor to antimony sulphide and cadmium sulphide applied as color in gum ; lead oxide, in varnish ; white lead as a component of the so-called molded wax, if the same does not amount to more than one part in one hundred ; lead chromate by itself or in association with lead sulphate, in oil or lacquer, covered by lacquer or varnish ; zinc colors insoluble in water, in rubber toys, if used in the coloring of the rubber, or as lacquer or oil color, applied with lac or varnish, and all vitrified t:olor applied with enamel. The provisions of § § 7 and 8 are strictly applicable to the objects therein mentioned, when these enter into the composition of the toys. 5. In book printing and lithographing in connection with the manufactures enumerated in § § 2, 3 and 4, only colors contain- ing arsenicum are forbidden. 6. Water colors of all kinds are not to be sold nor offered for sale as non-poisonous unless they are in accordance with the requirements of § 4. 7. Arsenical colors shall not be employed in the manufacture of tapestries, upholstery, carpets, curtains, wearing apparel, masks, candles and artificial flowers and fruits. This regulation does not apply to the use of arsenical mordants for the dyeing and printing of textiles, but fabrics so prepared shall not be employed in the manufacture of the articles enumerated in the preceding paragraph, if the arsenical compound is soluble in water, or pre- sent in amount greater than 2 milligrams to 100 square cent, of the finished fabric. The Chancellor of the Empire is authorized LEGAL ENACTMENTS. 37 to formulate in detail the method for estimating the amount of arsenicum. 8. The provisions of § 7 apply to the manufacture of writing materials, lamp shades and lamp decorations. The manufacture of sacred wafers is subject to the conditions specified in § i, but as regards those not intended to be eaten, the use of barium sulphate (heavy spar, fixed white), chrome green and cinnabar is allowed. 9. Water colors, or gelatin colors containing arsenicum, are not to be used in the preparation of paints for floors, ceilings, walls, doors or windows of living or work-rooms, nor for shades, shutters, curtains, furniture, or other household articles. 10. The regulations given in § i, do not apply to the in- gredients there enumerated, if such are merely present as impuri- ties unavoidable in the ordinary manufacture, and not essential constituents. ti. These regulations do not apply to the coloring of furs. 12. Whoever prepares, keeps or puts up food, drink or household articles in violation of the provisions of § i to 5, 7, 8, and 9, or sells or offers for sale articles prepared, kept or put up in violation of said provisions, or violates the requirements of § 6 or those of § 9, or sells or offers for sale articles made in violation of the provisions of § 9, may be punished by a fine not exceeding one hundred and fifty marks, or by imprisonment. 13. In addition to the penalties fixed by § 12, articles made, sold or exposed for sale in contravention of the provisions of this Act may be confiscated, whether the property of the accused per- son or not. If the prosecution or conviction of any particular person is impossible, the judgment may be limited to the con- fiscation. 14. The provisions of the law of May 14, 1879, relating to sale of food, drink, and household articles (Reichs-Gesetzbl., p. 146) remain undisturbed. The regulations given in § § 16 and 17 of that law, relating to violations of it, apply to the present enact- ment. 15. This law takes effect on May i, 1888, at which date 38 THE COAL-TAR COLORS. the imperial decree relating to the employment of poisonous colors, dated May i, 1882, (Reichs-Gesetzbl., p. 55), expires. Given under our royal hand and imperial seal, Ems, July 5, 1887. William. von boetticher. II. The Sonneberg Chamber of Commerce and Trade an- nounced in a bulletin of information, on December 4, 1887, an opinion as to the points in the law of July 5, 1887, touching the use of unwholesome colors in the manufacture of toys, and enum- erated the following colors, which under that law may be em- ployed unrestrictedly : All blue and violet aniline (that is, coal- tar) colors, all ponceaus, all orange colors, methyl green, brilliant green, malachite green, chrysoidin, naphthol yellow, Martius' yellow, eosin, phloxin, safranin, erythrosin, fuchsin, phenylene brown, and aniline black.* III. Announcement concerning the examination of colors and fabrics for arsenic and tin. April 10, 1888. By virtue of the provisions of § § i and 7, of the law relating to the use of injurious colors in the preparation of food, drink, or household articles, approved July 5, 1887 (Reichs-Gesetzbl., p. 277), I order that the following methods are to be pursued in the recognition of arsenicum and tin in the colors employed in food or drink and in the determination of the amount of arsenicum in fabrics containing arsenical mordants. For the Chancellor of the Empire, Berlin, April 10, 1888. von Boetticher. Appendix. Directions for the examination of colors and fabrics for arsenicum and tin (§ § i and 7, of the law relating to the use of injurious colors in the manufacture of food, drink, and house- hold articles, dated July 5, 1887.). * See publications of the Imper. Health Office, p. 132, No. 8. LEGAL ENACTMENTS. 39 A. Methods for detecting arsenicum and tin in artificially colored articles of food and drink. /. Solids. — With solids which are colored through the entire mass, 20 grams are to be taken. If colored superficially, sufficient of the exterior is to be scraped off to be equivalent to 20 grams of the material. Smaller amounts of material are to be used only when the full quantity is not obtainable. The test-piece is to be reduced to powder in any suitable manner and placed in a Berlin porcelain dish with a convenient quantity of hydrochloric acid of sp. gr. i.ioo to 1.120 and a quantity of water equal to three times the quantity of acid added. In general, 25 c. c. of acid and 75 c. c. of water will be sufficient; 0.5 gram of potas- sium chlorate are then added, the dish heated on the water-bath, and, when the fluid reaches the temperature of the bath, small quantities of potassium chlorate are added from time to time until the liquid acquires a uniform light yellow tint and becomes clear. Two grams of potassium chlorate will usually suffice for the operation. Water lost by evaporation is to be replaced. When the proper condition has been reached, about 0.5 gram more of the chlorate are added and the dish taken from the bath, cooled, filtered into a 400 c. c. flask, and the filtrate heated on the water- bath until all odor of chlorine has disappeared. The filter, together with any precipitate, is washed with hot water, the washings evaporated to 50 c. c, and the liquid, with any pre- cipitate that may be in it, added to the original filtrate. The total volume of the liquid at this point must be at least six times that of the hydrochloric acid taken. Thus, supposing that 25 c. c. of hydrochloric acid have been used, the volume must not be less than 150 c. c, preferably 200 to 250 c. c. The liquid is then maintained for three hours at from 60° to 80° C, while a slow current of pure well-washed hydrogen sulphide is passed through; the heat is then withdrawn, the gas being continued until the liquid is cold. It is transferred to a flask, the mouth of which is covered with apiece of filter paper, and allowed to stand for twelve hours in a moderately warm place. If a precipitate 40 THE COAL-TAR COLORS. be formed, it is to be collected upon a filter, washed with hydro- gen sulphide solution, and then, while still moist, treated with yellow ammonium sulphide which has been somewhat diluted with weak ammonium hydroxide. In general 4 c. c. of am- monium sulphide, 2 c. c. of ammonium hydroxide of sp. gr. 0.96, and 15 c. c. of water will be satisfactory. The residue on the filter, not dissolved by this mixture, is washed with water containing a little ammonium sulphide and the filtrate and wash- ings evaporated to dryness at a gentle heat in a porcelain dish, not over six cm. in diameter. The residue treated with three c. c. of red fuming nitric acid, the dish being covered by a watch glass, and the acid evaporated at a gentle heat. If the residue is still dark, the treatment with nitric acid must be re- peated until a mass appearing yellow when moist, is obtained. This is mixed, while still moist, with finely powdered sodium carbonate, until strongly alkaline, a mixture of one part of sodium nitrate and three parts of sodium carbonate added, and sufficient water to make a pasty mass, which is then thorcjughly mixed. The mass is heated in a crucible to sintering or incipi- ent melting ; a high heat is to be avoided. A colorless or white residue should be obtained. If the mass is colored, it should be re-heated with a little sodium nitrate, until the colorless condi- tion is reached.* The melt is dissolved in warm water and filtered through a wet filter. If tin be present, it will be found on the filter, in the form of stannic oxide, while all the arsenicum will be in the filtrate in the form of sodium orthoarsenate. If there be a resi- due on the filter, it must be borne in mind that minute amounts of tin may pass into the filtrate. The residue is washed with cold water, then three times with a mixture of equal parts of alcohol and water, the washings evaporated so that the total vol- ume including the filtrate does not exceed 10 c. c, and nitric acid added, drop by drop, until the liquid is acid. If a precipitate * If the melt persistently remains black it contains copper, owing to the slight solubility of copper sulphide in ammonium sulphide. LEGAL ENACTMENTS. 4I of Stannic hydroxide appear it is filtered off and washed as de- scribed above. The further procedure for the detection of tin is given below. For the recognition of the arsenicum, it is converted into ammonium arsenmolybdate. For this purpose, the liquid, rendered acid by nitric acid, as described above, is freed from carbonic and nitrous acids by warming, cooled, the clear (filtered, if necessary) solution, which should be about 15 c. c, mixed in a flask with about an equal volume of ammonium molybdate solution,* and allowed to stand without warmmg for three hours. If through incomplete washing of the hydrogen sulphide precipitate, any phosphate has been retained, a yellow precipitate of ammonium phosphomolybdate will separate; other- wise, the liquid will remain clear. The clear (if necessary, filtered) liquid is heated on the water bath for five minutes, at the boiling point.* If arsenicum be present, a yellow precipitate of ammonium arsenmolybdate, together with molybdic anhydride will separate. f . After standing for one hour, the liquid is decanted through a filter, the precipitate washed twice with a mixture of 100 parts of the molybdate solution, 20 parts nitric acid of sp. gr. 1.200 and 80 parts of water, and dissolved, by the aid of heat, in from two to four c. c. of ammon- ium hydroxide sp. gr. 0.96, four c. c. of water, filtered, if necessary, mixed with one-fourth its volume of alcohol, and then with two drops of the solution of ammonium chloride and magnesium chloride. The arsenicum separates on standing, as ammonium magnesium arsenate, more or less crystalline in form, which is to be collected on a filter and washed with as small as * Dissolve one part of molybdic anhydride in four parts of ammonium hydroxide (sp. gr. 0.96), and pour the solution into 15 parts of nitric acid (sp. gr. 1.200); allow the liquid to stand in a moderately warm place for several days and decant the clear portion for use. f It is best to continue the heating until the molybdic anhydride begins to separate. 4 42 THE COAL-TAR COLORS. possible a quantity of a mixture of one part of ammonium hydroxide, two parts of water, and one part of alcohol. The precipitate is to be dissolved in the smallest possible quantity of dilute nitric acid, the solution evaporated to small bulk, one drop of it placed in a porcelain basin and another on a glass slide. To the first drop, a solution of silver nitrate is added, then a drop of ammonium hydroxide sp. gr. .096 is applied to the edge of the mixture. If arsenicum be present, a red-brown streak will appear. The drop on the object glass is made akaline with the smallest possible quantity of ammonium hydroxide, by which there appears very soon, if arsenicum be present, a crystalline precipitate of ammonium magnesium arsenate. For the detection of tin, the filter or filters containing the stannic oxide are to be dried, burned in a porcelain crucible, and weighed.* Further examination for tin will be necessary only when the residue, after deducting the filter ash, weighs more than .002 gram. In this case, the residue is to be placed" in a porcelain boat which is inserted in a tube of hard glass, one end of which has been drawn out to a fine jet. A stream of pure dry hydrogen is passed through the tube, the temperature being slowly raised and continued until no vapor of water escapes, that is, until all the oxide is reduced. The boat is allowed to cool in the stream of gas, removed, tilted slightly, a few drops of hydrochloric acid sp. gr. i.io to 1.12, placed in the lower end, again placed in the tube and subjected to a slow current of the hydrogen gas. The boat is inclined so that the hydrochloric acid comes in contact with the reduced tin, and is then slightly heated. The tin dissolves, forming stannous chloride, with libera- tion of hydrogen. The boat is allowed to cool in the current of gas, removed, if necessary, treated with a few drops of a mixture * If the residue is black, in consequence of the presence of copper oxide, it is to be warmed with nitric acid and evaporated in the water-bath to dryness, and a few drops of nitric acid with a little water added, the residue collected on a filter, washed, dried, ignited and weighed. LEGAL ENACTMENTS. 43 of three parts of water and one part of hydrochloric acid, and different drops of the solution tested for tin, by mercuric chlor- ide, gold chloride and hydrogen sulphide, the latter test being tried both before and after the addition of bromine or chlorine water. A black residue, insoluble in the acid, remaining after the treatment of the contents of the boat with hydrochloric acid, may be antimony. //. Liquids, Fruii Jellies, and Similar Substances. — In such cases, a quantity of the material is to be weighed out that shall be equivalent to 20 grams of the dried substance. For raspberry syrup, 30 grams must be taken ; for currant jelly 35 grams, and for red wine, vinegar and such fluids, from 800 to 1000 grams must be used. Smaller quantities may be used only when the full amount is not obtainable. Fruit juices, jellies and such substances are treated exactly as directed above, with hydrochloric acid, potassium chlorate, etc.; dilute, non-acid liquids are concentrated by evaporation, to a small volume, and treated as before ; acid liquids are distilled to a small volume, the distillate is mixed with hydrochloric acid and saturated with hydrogen sulphide, any precipitate so ob- tained being added to that obtained from the liquid in the retort similarly treated. B. Procedure for the detection of arsenicum in yarn and fab- rics (§ 7 of the law).* * It is allowable for the investigator to make a preliminary test by Marsh's method, using a sufficiently large quantity of the material, and thus determine the presence or absence of arsenicum. Should the result be negative further procedure is unnecessary. [In this and similar cases, Reinsch's test, which is much more convenient than Marsh's, will be found sufficient for preliminary examination. It is advisable to use a rather large amount of hydrochloric acid, otherwise arsenates may be overlooked. The processes given in the text for the destruction of the organic matter are now not much employed, since the methods involving the use of sulphuric acid with or without nitric, are more rapid and satisfactory. These methods will be found described in Fresenius' Quantitative Analysis and other works of similar scope. Translator.] 44 THE COAL-TAR COLORS. Thirty grams of the material to be tested are cut fine and soaked in water at from 70 to 80° C. for from three to four hours. The liquid is filtered, any residue is washed, and the filtrate and washings are concentrated to about 25 c.c, cooled, mixed with 5 c.c. of pure sulphuric acid, and tested by Marsh's test, with due precautions. If an arsenical mirror is obtained it shows that arsenicum is present in the fabric, in a form soluble in water. If the result by the above test is negative, a further quantity of 10 grams is taken and the superficial area determined. In the case of yarn the area is to be determined by comparison with a fabric woven from yarn of similar size. If the quantities necessary for the examinations are not to be obtained, smaller quantities may be used, and this part of the test may, in such case, be carried out upon a portion of that which has been treated with water and afterwards dried. The yarn or fabric is to be cut fine, introduced into a hard glass retort of 400 c.c. capacity, and covered with 100 c.c. of hydrochloric acid sp. gr. 1.19. The neck of the retort is drawn out and bent at an obtuse angle, and the retort mounted so that the first portion of the neck points obliquely upward and the second portion sharply downward. The end of the neck is attached to a Liebig's condenser and the joint made tight with a caoutchouc tube. The condenser is attached by an air-tight joint to a receiver of 500 c.c. capacity, in which has been placed 200 c.c. of water, and which is immersed in a dish of cold water. The outlet tube of the receiver is connected in a suit- able manner with a Peligot's tube. About an hour after the addition of the hydrochloric acid, 5 c.c. of cold saturated solution of non-arsenical ferric chloride is introduced into the retort and heat applied. When the excess of hydrochloric acid has passed over the heat is raised until the liquid boils, and continued until the contents of the retort begin to foam. The liquid is allowed to cool, 50 c.c. of hydrochloric acid of sp. gr. 1,19 added, and the distillation resumed. The contents of the receiver, colored by organic matter, are mixed LEGAL ENACTMENTS. 45 with the liquid that has collected in the Peligot tube, diluted with distilled water to about 600 c.c, and treated, first warm, and then in the cold, with pure washed hydrogen sulphide. At the end of twelve hours the brown precipitate, consisting in whole or in part of organic matter, is collected on an asbestos filter, which rests in a funnel provided with a stopcock, and washed briefly. The cock is closed and the mass treated with a few c.c. of a solution of bromine in hydrochloric acid of sp. gr. 1.19, a watch glass being placed over the top of the funnel to avoid loss. After action for half an hour the liquid is allowed to run from the funnel into the flask in which the precipitate was orig- inally formed, on the sides of which some of the material remains. The residue on the filter is to be washed with hydro- chloric acid of the usual strength. The filtrate and washings are to be mixed with excess of ferric chloride, the mixture introduced into a distillation apparatus of smaller size, but con- structed as before detailed, the flask containing the solution be- ing rinsed with hydrochloric acid of the usual strength, the rinsing being added to the contents of the retort. The distilla- tion is conducted exactly as before described. The distillate is usually clear and colorless. It is diluted to about 700 c.c, pre- cipitated with hydrogen sulphide, as before directed, and after twelve hours standing the precipitated arsenious sulphide is col- lected on a filter (which has been successively washed with dilute hydrochloric acid, water and alcohol, dried at 110° C, and weighed), washed with water, absolute alcohol, warm hydrogen sulphide solution, absolute alcohol again, dried at 110° C, and weighed. The quantity of arsenicum is calculated, and from the data obtained in the original measurement the proportion of arsenicum in 100 sq. cm. of material may be ascertained. England. In the Sale of Food and Drugs Act of 1875, paragraph 3, to which Mr. Otto Hehner, of London, has kindly referred me, is found to be to our purpose. ** 3. No person shall mix, color, stain, or powder, or order or 46 THE COAL-TAR COLORS. permit any other person to mix, color, stain, or powder, any article of food with any ingredient or material so as to render the article injurious to health, with intent that the same may be sold in that state, and no person shall sell any such article so mixed, colored, stained, or powdered, under a penalty in each case not exceeding fifty pounds for the first offence; every offence after a conviction for a first offence shall be a misdemeanor for which the person, on conviction, shall be imprisoned for a period not exceeding six months at hard labor." France. (This abstract is given by Dr. Weyl in the original French.) LIST OF HARMFUL AND HARMLESS COLORS. L SUBSTANCES THAT MAY BE USED. Mineral Colors. WJiite, — Chalk. Precipitated barium sulphate (to be used in small amount.) Blue. — Prussian or Berlin blue, ultramarine. Violet. — Violet ultramarine. Brown. — Ochre, manganese brown. Green. — Green ultramarine. Yellow. — Yellow ochre. Organic Colors. White. — Farina flour, starch. Red. — Cochineal carmine, carthamic acid (from saffron), red- wood, artificial alizarin and purpurin, cherry and beet juices, lakes prepared with these substances. Orange. — Annatto ; mixtures of harmless red and yellow colors. Yellow. — Saffron, safiflower, turmeric, quercitron, extract of yellow wood, French berries; aluminous lakes prepared with these colors. Green. — Spinach green, Chinese green ; mixtures of harmless blue and yellow colors. Violet. — Archil, India wood ; mixtures of harmless blue and red colors. LEGAL ENACTMENTS. 47 Blue. — Indigo, litmus, Archil blue. Brown. — Caramel, liquorice, extract of chestnut wood, ex- tract of catechu. n. SUBSTANCES NOT TO BE EMPLOYED. Mineral Colors. Coftfaining Copper. — Mountain blue. Containifig Lead. — Massicot red lead, orange mineral, Paris yellow, Cassel's yellow. Turner's yellow, white lead, silver white, Naples yellow, chrome yellow, orange chrome. Containing Barium. — Barium chromate, yellow ultramarine. Containing Arsenicum. — Copper arsenite, Scheele's green, Schweinfurth green, mixed green, also mercuric sulphide (vermilion). Organic Colors. Gamboge, aconite, fuchsin, and derivatives, e.g., Lyons blue, eosin. Colors containing nitro-groups, e. g., naphthol yellow, Victoria yellow. Colors prepared from diazo-compounds, e. g., tropseolins and xylidine red. Italy. [An abstract of these regulations is given by Dr. Weyl in the original Italian. They provide that the sale, keeping for sale, or dealing in any article of food or drink which is known to be spoiled, diseased, adulterated, or otherwise injurious to health, and contrary to the regulations, may be punished by fine or im- prisonment, maximum and minimum penalties and terms being enumerated. The manufacture and sale of vessels, etc., intended to contain articles of food and drink, which vessels, etc., contain or are coated with any metal or varnish or other covering, which may be likely to make the food injurious, are forbidden. The Superior Council of Health, with the approval of the Minister of the Interior, is authorized to issue a list of colors con- sidered injurious, and which are not to be used in the preparation of food, drink, toys, household articles, etc. Heavy fines are imposed in case of the use of the substances so prohibited.] 48 THE COAL-TAR COLORS. Abstract from regulations of the administration of the municipal- ity of Milan, {not yet p?'oclai?ned). A. It is forbidden to add coloring matters of any kind to the naturally colored articles of food and drink, such as wine, wine- vinegar, fruit juices, preserved fruits, preserved vegetables, such as saffron, etc. Paper, tissue, etc., used for wrapping articles of food, must not be colored with poisonous colors, and the colors denominated as poisonous in the law of the German Empire of July 5th, 1887, are hereby designated as poisonous. For the coloring of articles of food and drink not naturally colored, and of which the practice of artificial coloring is well known, for instance, liquors and confections, the employment of the poisonous colors referred to above, as well as all coal-tar colors not cited below, is until further notice forbidden : certain azo-colors and purpurin are permitted. Inasmuch as several of the colors here designated occur in commerce under various names, any one who intends to employ such color will be obtiged to ascertain whether it belongs to the permitted class. AUSTRIO-HUNGARY. In the official announcement of March 4, 1824, Z. 11379, the harmful colors which are not allowed to be used for painting toys, or for candies, and the harmless ones which are permitted for these purposes, are enumerated as follows: — A. NOT ALLOWED FOR PAINTING TOYS. White lead, zinc white. Orpiment, king's yellow, Naples yellow, massicot, English yellow, mineral yellow, chrome yellow, and gamboge. Verdigris, Braunschweig green, mountain green, Bremen green, Swedish or Scheele's green, mitis green, Vienna green, Schvveinfurth green. Mountain blue, mineral blue, smaltz, Berlin blue, when con- taining copper. Vermilion, red lead. LEGAL ENACTMENTS. 49 • • HARMLESS AND THEREFORE PERMITTED. Chalk, gypsum, white bone ash, ivory white, hartshorn ash. Dutch pink, turmeric, yellow ochre, orlean (an infusion of yellow wood mixed with one-fourth of alum and gum.) Sap green, all greens made from harmless yellow and blue colors, Veronese green. Pure Berlin blue, new blue, indigo solution with starch, Saxon blue, solution of indigo in sulphuric acid, litmus, sap blue, and cornflower blue. Carmine, lac, stick-seed, madder, and Florentine lac, Ar- menian bolus, pure ferric oxide, Pernambuco and Brazil wood infusion, mixed with alum and gum. B. For candies the following colors are regarded as harmful : cinnabar and red lead, yellow, blue and green, colors above designated as harmful, with mixtures of such yellow and red colors and such red and blue colors, imitation gold and silver leaf. As harmless, the following : juice of red berries, kermes, bearberry, red-beet juice, onion peelings, infusions of cochineal with cream of tartar, of red poppies, of bluebottle (Centaurea cyanus, L.), saffron, safflower, turmeric, infusion of "marigold flowers, expressed juice of blue flowers, such as bluebottles and violets, litmus, spinach juice, mixtures of harmless yellow and blue colors. Pomegranate yellow, decoction of oleander with sodium hydroxide, cochineal infusion with lime water, mixtures of harmless blue and red colors, genuine gold and silver leaf. 11. According to the ministerial announcement of September 19, 1848, Z. 3075, of a governmental order of October 5, 1848, Z. 53 169, only the following colors are to be used for painting edibles, confections, and tragacanth preparations, as well as all show pieces prepared by candy makers and not in- tended for consumption. White. — Tragacan th. Red. — Cochineal, carmine, kermes, infusion of red poppy. Yellow. — Saffron, safllower, and turmeric. Blue. — March violet, bluebottle, indigo, Prussian blue, ultramarine, sea blue (a form of artificial ultramarine). 50 THE COAL-TAR COLORS. Green. — Spinach juice, mixtures of permissible blue and yel- low colors. Violet, — Mixtures of harmless blue and red colors, cochineal infusion with lime water. Gold Color. — Pure gold leaf. Silver Color. — Pure silver leaf. All other colors, no matter what name they may bear, are forbidden to the extent that even to keep them in stock in the business department or work rooms of any given establishment, will constitute an infringement of these regulations and bring about liability to the penalties provided. III. In accordance with the orders of the government of lower Austria (January 23, 1859, Z. 55507), the provisions for the employment of Alpine red (murexide) as a color were designated as follows: ''This color can only be made permanent by the employment of mercuric chloride. In its preparation the work- men come frequently and for considerable periods in contact with the mercuric chloride, and by neglect of the proper precau- tions, serious results must occur. To prevent, as far as possible, the injuries that must follow long contact with materials charged with this substance, it is necessary that the workmen engaged in using murexide avoid handling it with abraded hands ; that they should not allow the mercuric chloride solution to remain in contact with the skin longer than is absolutely necessary, and as often as such contact occurs should rinse their hands with clean water, and take especial care to wash the hands prior to taking or preparing food. This information is given in order that those in charge of such establishments shall not neglect to give neces- sary instructions to workmen." IV. Regulations promulgated. May i, 1866, by the Imperial Secretary of State for Austria, relating to the employment of poisonous colors and unwholesome preparations in various articles of household use, and to the sale of the same. (R. G. Bl. Royal Austrian Empire, p. 137.) Quoted from publications of the Imperial Health Office, 1887, 351, No. 23. The employ- ment of colors containing metals (except iron), gamboge, picric LEGAL ENACTMENTS. 5 1 acid, or aniline, is forbidden for all articles of consumption, food or drink, including devices and figures made from starch and sugar. Preparations and colors containing arsenicum, antimony, lead, cadmium, copper, cobalt, nickel, mercury (with the exception of pure mercuric sulphide), zinc, or gamboge, are not to be em- ployed for coloring or decorating children's toys. The materials, the employment of which is forbidden in the above paragraphs, or conditionally permitted, are not to be used on earthenware employed for holding food, except when the coloring material is burnt in. Artificial flowers colored with arsenicum compounds, or natural flowers of which any part may have been tinted by dipping in arsenical solution, are only allowed when the falling off of any of the material is completely prevented by varnish. Tapestry containing arsenical colors will only be allowed when the portions so colored are protected by a varnish coating. The employment of arsenical colors for the painting of walls of . living rooms, or other places where persons collect, is forbidden. The employment of any substance which in any form or manner in which it is used endangers health, is forbidden in the prepa- ration of articles of food, table and culinary ware, clothing, and all kinds of toilet articles. In addition to the manufacture of the articles which do not accord with the preceding conditions, trading, retailing, or other dealing in them is forbidden. Violations of these regulations which are not provided for by the general penal code are punishable by the provisions of the regular ministerial orders of September 30, 1881, R. G. P. L. 198. Signed, Count Belcredi, m. p. ; Baron von Wiillerstorf, M. P. ; Kt. von Komers, m. p. V. In reply to a formal question as to what course is to be pursued when articles of food have been found to be colored with aniline red, free from arsenicum, and, therefore, not injuri- ous to health, the Royal Imperial Secretary of the Interior, by a proclamation of November 21, 1881, Z. 16033 (State pro- clamation, December 19, 1881, Z. 75960) after consultation with the chief sanitary authority determined not to amend the regulations of May i, 1866, since, although it is a fact that 52 THE COAL-TAR COLORS. fuchsin free from arsenicumj is now in the market, no evidence is at hand that a preparation of poisonous quality is not in com- merce under the same name. Further, the question as to the poisonous or non-poisonous character of the aniline colors free from metal is still in dispute, and observations are on record to the effect that the continued consumption of liquids colored by fuchsin free from arsenicum has resulted in material disturb- ances of health. The use of fuchsin as a coloring material in all kinds of food is all the less to be permitted since coloring matters are not wanting which suffice for the purpose and are unsuspicious from a sanitary point of view. VI. Regulations of the Royal Imperial Austrian Secretary of the Interior concerning the employment of aniline or other coal-tar colors in the preparation of articles of food, dated March i, 1886, R. G. P. L. (Reichsgesetzblatt fiir die im Reich- rathe vertretenen Konigreiche und Lander. Quoted from the publications of the Imperial Health Office,. Germany, 1886, . 348). The employment of colors produced by chemical 'treat- ment of 'the aniline or other coal-tar derivatives, including roso- lic acid produced by various methods, in the preparation of all articles of food, is prohibited. In accord with §§ i and 6 of regulations of May i, 1866. Taaffe, m. p., Prezak, m. p., Pino, m. p. VII. Supplement relating to the application of rosolic acid to the coloring of articles of food, added by the Royal Imperial Austrian Secretary of the Interior. (Quoted from the publica- tions of the Imperial Health Office, 1887, 351, 23.) In answer to the formal question as to the permissibility of the use of rosolic acid for coloring articles of food, the following is issued with the consent of the chief sanitary authority : ^' In view of the more exact information acquired as to the composition of the compounds obtained from rosaniline by chemical action and applicable as coloring materials, the expression in § i of the regulations of May i, 1866, ' the employment of colors which contain aniline,' etc., must not be taken in the sense that the said colors contain aniline, but rather the expression must be SCOPE OF THE INVESTIGATION. 53 understood to mean colors produced by chemical action on aniline. In this sense, rosolic acid prepared from rosaniline must be regarded as a derivative of the latter, and hence, as an aniline color, is subject to the conditions of § i of the afore- mentioned regulations. As to the second variety of rosolic acid prepared by the action of oxalic acid upon carbolic acid, which differs as to composition and properties very slightly from the acid first named, § i of the aforementioned regulations does not apply, but § 6 of the same does apply all the more positively, since, apart from the absence of trustworthy knowledge of the action of pure rosolic acid upon the human organism, it comes into commerce contaminated by the injurious materials employed in its manufacture, and therefore, in the manner and form in which it is employed, it is actually liable to endanger health. The Secretary of the Interior takes this opportunity to advise that recently numerous organic substances, especially prepared from coal-tar and applicable as colors, have been prepared, which on the one hand, on account of their unknown action and un- known influence on the human organism, on the other hand from their contamination with substances of suspicious influ- ence, must not be employed in the preparation of food and drink, and therefore, are to be dealt with in accordance with provision of § 6 of the regulations above quoted." SCOPE OF THE INVESTIGATION. The review of the existing literature shows that certainty as to the unwholesomeness or toxic nature of the coal-tar colors has not yet been attained, and cannot be attained because re- searches with definite purpose are almost entirely wanting. On the other hand, the majority of civilized nations have been con- strained to forbid, by rules and regulations, the employment of certain colors in the preparation of food or household articles. Since my labors in this field forced me to the conclusion that a rational legislative control of this question could only be based upon more comprehensive information than seemed to be attain- 54 THE COAL-TAR COLORS. able, I resolved to test the existing statements concerning cer- tain coal-tar colors, and further, to carry out investigations on as many of these dyes as possible. Thus, following research was inaugurated, and as already stated was pursued in strictly practical relations. Frequently, to the regret of the experi- menter, interesting lines of research must be passed by, which would lead to information concerning the ultimate products re- sulting from the ingested substances, the origin of the toxic symptoms, and the disturbances of metabolism under the in- fluence of the foreign materials. The abundance of new observ- ations offered added an additional reason for leaving these side- issues untouched, at least in the preliminary stage. No excuse should be needed for the frequent allusion to questions of theor}', since the data herewith presented are not the result of mere chance, but have been developed under the guidance of those theoretical views concerning the constitution of the coal-tar colors which have been wrought out by modern chemistry. METHODS. Selection of Colors. — In consequence of the great number of these colors and the constant appearance of new ones in the market, it has been impossible to test all or even the greater portion. A selection must therefore be made, and it will be well to choose first those which are in some manner suspicious, from having caused poisoning in their intentional or uninten- tional use. Moreover, the colors most suitable for practical use must be taken into consideration. Even a tolerably complete list of such, however, is not easy to obtain, since the employ- ment of a given color may be a matter of fashion, and the dif- ferent makers have some interest in concealing from their com- petitors which colors they sell in largest amount, and, further, the consumer cannot always find out what colors are used to bring about a given tint. Perhaps it may become possible to pronounce upon the harmfulness of these colors by a sort of in- duction when tests have been made of many colors, including METHODS. 55 the most various groups, without subjecting every one to test. A connection between chemical composition and physiological action is certainly to be expected. It remains to be considered whether the toxicological investi- gation should be limited to the color in a condition of absolute purity or only to the commercial form of it. Tests of the pure colors have preeminently theoretical significance, since the degree of toxic action and the relation between chemical constitution and physiological effect can be most clearly indicated. Tests of the commercial forms, however, have greater practical value, and only when a commercial article is found to be poisonous, will it be necessary to inquire further whether the poisonous action is an essential property of the color or arises from accidental admixture. This point will be made more clear by some exam- ples. Fuchsin and its congeners, methyl violet and malachite green, are, as is now established, almost without poisonous action. Whoever would pronounce an arsenical aniline color poisonous without being aware of its arsenical contamination, would easily fall into the error of assuming that all colors analogous to fuchsin would be poisonous. The reverse is the case with the poisonous dinitrocresol (saffron-substitute). The commercial preparation contains usually about forty per cent, of ammonium chloride. This addition does not develop the poisonous action of the color, but, as is obvious, diminishes it materially. Therefore, according to the purpose of the investigation, whether it lean toward theoretical or practical information, the toxicological experiment must deal either with the pure product or the com- mercial form. Should the commercial article be found poisonous, a further inquiry will be needed to determine if it can be made harmless by the removal of any impurities. Selection of the Animals for Experiment. — Only rarely will the toxicologist be able to make researches as to the effect on human beings. At the most, a case of poisoning which has come to chemical or legal notice will be investigated scien- tifically. Investigations, as far as they have practical value in relation to the human organism, must be carried out on animals 56 THE COAL-TAR COLORS. which in their organization and chemical functions are as near as possible similar to human beings. Physiologists know, and it will not be necessary for me to stop to establish the fact, that these requirements are best fulfilled by the dog. The ape, by reason of costliness, scarcely comes into consideration. It is naturally of great scientific interest to examine the effect of any material upon as large as possible a number of animals of vari- ous types. Even the higher and lower plants may be taken into consideration in these experiments. It must also not pass un- noticed that occasionally conclusions may be drawn from experi- ments on other animals. For instance, for preliminary researches, frogs and rabbits have value for economical reasons. The con- clusions derived from such experiments must be accepted with great deliberation, since it happens that rabbits will bear without injury doses which will seriously, nay, even fatally act upon the dog, as I have already shown to be the case with Martins' yellow. Fishes, for instance, are only affected after several hours by doses of curara to which frogs quickly succumb. Chickens bear Tnore than ten times, Guinea pigs more than three times, the dose of strychnine that is fatal to rabbits. Human beings are more sensi- tive to morphine than are Guinea pigs. These and similar facts serve to make us cautious in interpreting results obtained in experiments on dogs. It is only because we have no other satis- factory method, that we use the dog as the animal for experiment and apply the results thus obtained to the human being. Manner of Administration. — Of course, only exactly measured and weighed doses of the material of which the effect is to be studied, should be administered to the animal. This is necessary not only in order that the results obtained by one experimenter may be susceptible of confirmation by another, but more especially because most materials do not act the same in small as in large doses. Further, the material to be tested should, whenever possible, be administered in dissolved form. In case a suitable solvent is not available, the material should be given in fine powder, or suspended in water or other liquid. The selection of the solvent is consequently of importance. Such METHODS. 57 liquids only are applicable as are either without action when ad- ministered in moderate quantity, or at least of but feeble effect : water, very dilute acids, alkalies, or salt solution are suitable. Alcoholic, ethereal, and similar solutions have but a limited application and must not be employed unless absolutely neces- sary. In doubtful cases, control experiments are indispensable. Omitting special cases, a substance may be administered in four different ways : by the mouth, by direct injection into blood, by hypodermic, and by endermic application. (i) Administration by the Mouth. — Administration by the mouth is to be preferred unless special reasons to the contrary exist. This is best accomplished by means of the food. Fre- quently, however, the animal refuses to eat food mixed with foreign matters. In such a case it can either be introduced by force, or the oesophageal tube can be used. The latter consists of an elastic rubber tube of a diameter corresponding to that of the gullet, the upper end terminating in a funnel. The intro- duction of the apparatus requires the aid of an assistant, but generally does not involve much difficulty. It is best that any solution introduced directly into the stomach by this apparatus, should be warmed to blood heat. The quantity of liquid intro- duced should not exceed thirty to fifty c.c. even with large dogs. Vomiting may easily be produced if larger quantities are intro- duced. In order to diminish the irritating action of the sub- stances administered, a soothing menstruum such as milk or pep- tone solution should be employed. Vomiting takes place more quickly on an empty stomach than with one filled with food. The oesophageal sound can be employed with good results for pumping out the stomach. The action can be assisted by pressure over the region of the stomach and by suction. (2) Injection into the Blood — /. g.-ii^-S .1. '^ "^ i ^!5 <::: C3 ^ ex, .^^ ■ a. 3 line -di nze och 3 rt zo-o ona snes •- >i (U l- r^ >- c ;% XI -D O -" a t: ^^ < m o H U o ^ o -c aj 2- c O i: 3 3 "^ •:= c D- O C/2 C C3.y I I u o o o 15 o o W 1-ri ' o ^ ffi ffi "5 ^ ^ ^ ;zi in lO X X o o r-4 .-H U u 1 ^ 1 o CO CO u X to u -u •J^ ^^ 'S M , ^ o ■ >» V ^ eo a, CA) o M a a N (U O O en X 'o d c ^4-1 o to X to O ■73 5^ •* X to .2 a, o ■2 X 53 O 'o a rt o "c o o •St u ^ u <52. u N C^ , CO o c^ o CQ 4> N O N rt C4 X o 6 tsl C3 O 's rt o n o C/3 X to u 12; 6 c X d:"" P «£> o to 1 1 »2-nitrazotin) was thus produced. The influence of the sulphonic group could be thus indicated. This may be attached either to the benzene or to the naphthalene nucleus, /-nitrazotin contains at the same time a nitro- and a sulphonic group, while archil-substitute, which is derived from the a-amido- Il6 THE COAL-TAR COLORS. naphthalene, also contains nitro- and sulphonic groups. Un- fortunately, further investigations directed to the introducing of other groups into the color molecule, in order to obtain information as to their influence upon the toxic action of the body so produced, were frustrated, because other intermediate products were not obtainable by me. Bismarck brown and chrysoidin are much used. Azarin S has not been examined. Diphenylamine orange and metanil yellow are isomeric. Bismarck Brown. This color, also known as Manchester brown, phenylene brown, Vesuvin, aniline brown, leather brown, cinnamon brown, canelle, English brown, and golden brown, is produced by the action of two molecules of sodium nitrite on three molecules of ;;/-diamidobenzene hydrochloride in watery solution. It is not positively established whether it is triamidoazobenzene hydrochloride, as usually assumed, ^ N = N NH. NH^HCl NH„HC1. or, more probably, a compound of w-diamidobenzenedisazo-;;^- diamidobenzene. The latter form is the more probable from the mode of formation, and in this case Bismarck brown would belong to the disazo-colors. Typical Reactions. — Dark-brown powder, producing a brown solution in water, which gives with hydrochloric acid a brown precipitate easily soluble, and with acetic acid a brown solution, but no precipitate ; with sodium hydroxide, a brown precipitate difficultly soluble ; with ammonium hydroxide, a brown precipi- tate soluble in excess, and with ammoniacal copper solution, a brown precipitate difficultly soluble in hot water, reappearing on cooling. The powder dissolves in concentrated sulphuric acid to a brown solution which becomes reddish on dilution. Bismarck OBSERVATIONS ON ANIMALS. II 7 brown is one of the earliest-discovered azo-colors, but is still used to a large extent for the coloring of wool, leather, and jute. Cotton is dyed only after previous mordanting with tannin and tartar emetic. The specimens used in the experiment were from the Aniline Manufacturing Company of Berlin.* Exp. T. — Dog weighing 5690 grams, selected June nth, and on that and the following day showing no albumin in the urine. On June 13th, at 10.30 A. M., 2 grams were administered by the oesopha- geal tube. At 12 vomiting occurred. June 14th, 10 o'clock, 2 grams : vomiting at 12, no food taken. June 15th, no food taken, animal moved about a little. June i6th, 2 grams, two hours after which marked vomiting occurred. June 17th to 20th, no nourishment taken except water. June 21st, food taken, animal more lively, albumin in urine. June 22d, 5 grams, animal vomiting for one-half hour after administration. June 23d to 27th, almost no food taken, albumin in urine. June 28th, improving. June 30th, food taken, albumin in urine. Animal was under observation until July 15th. Finally only slight traces of albumin were detected in the urine and the appetite was restored. Exp. 2. — Dog weighing 29500 grams, selected April 29th, was found to have no albuminuria. On April 30th, received 5 grams by the oesophageal tube. May ist, urine brown, animal lively, appetite normal. May 2d, 5 grams by the tube. Bismarck brown was recog- nized in the urine by dyeing wool and chemical tests. May 4th, 5 grams administered. Urine brownish, no albumin. May 5th, urine normal, no color, no albumin. May 8th, 15 grams administered. Animal vomited once after the administration. May 12th, ate little, seemed sick. May 14th, seemed lively. May 15th, 15 grams given ; vomited after the administration. May i6th, no food taken, no albuminuria. May i8th, animal normal. May 22d, normal. Weight 28900 grams. Exp. J. — Dog weighing 5500 grams, received during an entire month, daily, .25 gram of Bismarck brown with its food. The animal continued in good health during the entire time, did not vomit and ate as usual. It gained during the experiment about 350 grams. Exp. 4. — Dog weig^hing 63CO grams, received in the course of 20 [* I have found traces of copper in all the commercial samples of Bismarck brown I have tested. — Trans.] Il8 THE COAL-TAR COLORS. days, 9 injections, each .i gram, of Bismarck brown in 8-10 c. c. of sterilized water inserted below the skin of the back. The animal re- mained entirely normal. Urine was normal color and contained no albumin. Exp. J. — Same animal received three injections of .1 gram each of Bismarck brown in 8-10 c. c. of sterihzed water introduced into the abdominal cavity. Animal showed slight elevation of temperature and refused food. Urine remained uncolored, and in a week the animal had completely recovered. Bismarck brown produces, when administered to dogs by the stomach, even in doses of .35 gram per kilo of body-weight, vomiting and albuminuria. Further disturbance is not noted, even with large doses. Small doses, .045 gram per kilo of body- weight, even when frequently administered, seem to be entirely harmless. Doses of .016 gram are harmless, even when intro- duced into the subcutaneous cellular tissue. The same dose in- troduced into the abdominal cavity induces slight disturbances. With small doses the urine remains uncolored. Only when con- siderable quantities are administered does the unaltered 'color appear in the urine. Soudan I. This was first prepared by C. Liebermann from diazobenzene chloride and /5-naphthol. The material used in my investigations was prepared by myself in this manner. I obtained the color by recrystallization from 90 per cent, alcohol in beautiful red crystals. It is employed in coloring lacquers, oils, and liqueurs. It is aniline-azo-/?-naphthol : — N = N HO. Typical Reactions. — In the pure form it is in red crystals, in- soluble in water, soluble in alcohol, to an orange-red solution. The alcoholic solution produces, with aqueous sodium hydroxide or ammonium hydroxide, a red-brown solution. With ammoniacal copper solution, a brown precipitate. The powder dissolves in OBSERVATIONS ON ANIMALS. II9 concentrated sulphuric acid to a fuchsin-red liquid, which on dihition with water yields an orange-yellow precipitate. Exp. I. — Dog weighing 11900 grams, selected June 7th, il Urine alkaline, no albumin. June 8th, 2 grams administered by the tube. June 9th, no administration. Urine normal color, alkaline, no albumin, sulphates abundant. The distillate obtained from the urine, strongly acidulated with hydrochloric acid, gave a distinct precipitate with bromine water. June loth, no administration. June nth, 2 grams by the tube. Animal lively, normal fasces. June 12th, vomit- ing, but otherwise lively. Urine almost free from phenol. Two grams by the tube same date. June 13th, 2 grams administered. Urine now dark brown, alkaline, albumin distinctly present, also sul- phates. June 15th, 2 grams. June i6th, animal lively, took food. Weight II 550 grams, therefore lost 350 grams in ten days. June 22d, animal lively. Urine normal in color, no albumin. June 23d, 5 grams administered. Urine rather darker than normal. June 24th, took little food. June 25th, 5 grams administered, but little food taken, June 26th, faeces yield to hot alcohol much of the unchanged dye stuff, which by cooling with the solvent is deposited in red crystals and gives the above reaction. Very little albumin in the urine. June 27th, animal lively, but little appetite. June 29th, food taken, urine uncolored. June 30th, animal lively, very little albumin in the urine. The color, in the doses administered, is not entirely harmless, since a limited albuminuria seems to be brought about. From want of a suitable solvent, subcutaneous injections could not be made. Metanitrazotin. This an azo-color, which seems not to have been described. I obtained it by the conjugation of diazotized ;//-nitraniline with ^-naphthol. Its mode of formation suggests the following form- ula : — ■ ■ N = N ^ .HO. NO., It may be called ;;z-nitranilineazo-/?-naphthol. It is scarcely soluble in 90 per cent, alcohol, difficultly soluble I20 THE COAL-TAR COLORS. in benzene and glacial acetic acid. It is dissolved in warm alco- holic solution of sodium hydroxide, filtered, and precipitated with hydrochloric acid. The precipitate is freed from the ad- hering liquid by the aspirator and washed with hot water. It presents the form of a red powder. The alcoholic solution pro- duces, with sodium hydroxide and ammonium hydroxide, a Burgundy-red solution which is changed to yellow by acids. The powder dissolves in concentrated sulphuric acid to a fuchsin-red liquid which changes to orange-yellow by dilution with water, and gives a greenish-yellow fluorescence, possibly by reason of a very finely divided precipitate. Exp. /. — Dog weighing 12600 grams, selected July nth, showed traces of albumin in the urine. July 12th, same condition. One gram by the oesophageal tube. Urine pale, alkaline, traces of albumin, but phenol hardly recognizable. July 13th, 2 grams administered. Urine abundant, pale yellow, turbid, strongly alkaline; addition of acid causes strong effervescence ; no sugar, traces of albumin, no phenol. July 14th, 2 grams by the tube. Urine strongly alkaline. July 15th, 2 grams by the tube. Urine abundant. July i6th, animal tively ; weight, 12,450 grams, consequently a loss of 150 grams in five days. A second dog, weighing 5600 grams, received ten doses of i gram each during twenty days. Animal remained lively, urine free from albumin and not abnormally colored. It was under observation for five weeks. I supposed, in view of the observations made on nitro-colors, that metanitrazotin would be poisonous, but, in spite of the nitro-group that is present, it is shown to be harmless. Paranitrazotin. I prepared this color from diazotized /-nitraniline and from /S-naphiholmonosulphonic acid S. The color is sodium /-nitranilineazo-/5'-naphtholmonosulphonate. Its constitution is probably : — N = JNU, OBSERVATIONS ON ANIMALS. 121 Typical Reactions. — It is a red-brown powder, producing with water an orange-brown solution. This solution gives with sodium hydroxide and ammonium hydroxide a fuchsin-red color; with copper sulphate, no change ; with ammoniacal copper solution, a red-violet precipitate soluble to the same color in ammonium hydroxide. The powder dissolves in concentrated sulphuric acid to a bright red liquid which changes to orange-yellow by dilution with water. The mode of formation suggests the name, parani- trazotin. A rabbit weighing 1500 grams received two doses of 2)^ grams each by the oesophageal tube in the course of three days. It remained lively. Further investigations were prevented by a want of material. Orange II. This color is also known as orange 2, /?-naphthol orange, tropseolin 000 2, mandarin, mandarin G extra, chrysaurin, and golden orange. I obtained this color myself from /-diazo- benzensulphonic acid and /9-naphthol. It crystallizes from water in orange-yellow plates. It is azo-/5-naphthol-/-azobenzenesul- phonic acid. N = N HO HSO3 Wool and silk are colored orange in an acid bath ; cotton only after previous mordanting. Typical Reactions. — Orange-red crystals easily soluble in water to an orange-red solution. The watery solution gives with hydro- chloric acid a brownish precipitate, dissolving in alcohol to an orange-red liquid. Sodium hydroxide and ammonium hydroxide give red-brown solutions. Ammoniacal copper solution pro- duces a gelatinous red-brown precipitate. The powder dissolves in concentrated sulphuric acid to a fuchsin-red liquid, which, on dilution with water, gives a brownish-red precipitate. 122 THE COAL-TAR COLORS. Exp. I. — Dog weighing- 10500 grams received, July 4th, 5 grams by the tube. Urine red, diarrhoea, (?) vomiting. (?) The red urine was decolorized by warming with stanTious chloride and hydrochloric acid. July 5th, no administration. Urine colored by the dye stuff, vomiting (?). July 6th, urine red. July 7th, urine weak red with much sediment. July 8th, urine scanty, much sediment. July 9th to 1 2th, urine alkaline, turbid, contains albumin. July 13th, 7 grams by the tube. July 14th, urine orange-red, no food taken, diarrhoea. July 15th, animal ate little, urine weak reddish. July 17th, 2 grams ad- ministered. No food taken ; diarrhoea ; urine neutral, weak red, very turbid, doubtful traces of albumin. July i8th, animal very miserable, eyelids adherent. July 19th, no administration, animal in bad con- dition. July 20th, much albumin in the orange- colored urine; animal very miserable; 40° rectal temperature. July 27th, animal very weak ; urine orange-red, colored dark red by sodium hydroxide ; acid turns it yellow. Cotton easily dyed. July 23d, animal found dead in its cage. July 24th, post-mortem showed much fatty tissue of normal color, muscles normal in color, stomach and intestines pale ; in the stomach and upper section of the intestines numerous abscesses, recent and just cicatrizing; liver somewhat fatty degener- ated ; kidneys pale ; epithehum fatty ; lungs normal ; heart pale, containing much white coagula ; brain not tinged. Exp. 2. — A white rabbit, weighing 2250 grams, died within twelve hours after the administration of 3 grams of the color. Four hours after the administration the animal was running about the room, lively. Post-mortem was, through accident, omitted. Exp. J, — Dog weighing 4300 grams received, December 12th, .5 gram dissolved in about 10 c. c. of lukewarm water, injected under the skin of the back. December 12th to 14th, urine alkaline, some albumin, no sugar; color weak orange. December 15th, no abscess at the point of injection, animal lively and took food. December i6th, .25 gram subcutaneously on the opposite side of the back. Urine orange red, acid, traces of albumin. Wool easily dyed in the liquid acidulated with sulphuric acid. Dec. 17th, .5 gram subcutaneously. No abscesses, some diarrhoea. Dec. 18th, rectal temperature 39.5°; right eye closed and inflamed ; traces of albumin ; urine strongly orange ; dyes wool easily. Dec. 19th, coryza better, but cataract appearing. .5 gram administered subcutaneously. Urine red orange; animal lively. Dec. 20th, no injection; little albumin; animal trembled. Dec. 21st, but little albumin. .75 gram given OBSERVATIONS ON ANIMALS. 1 23 in two places on the back. Dec. 22d, animal very miserable ; trembled and snarled ; but little albumin. Dec. 23d, continued the same. Dec. 25th, abscesses developed at the point of injection of Dec. 2 1 St. Dec. 26th, animal livelier. Dec. 27th, abscesses opened spontaneously ; animal weighed 3840 grams, having lost, therefore, 460 grams in fifteen days. Jan. 2d, abscesses nearly healed ; animal hvely ; took food. Jan. 3d, animal began to lose hair. Jan. 14th. almost without hair. Weight, 3890 grams ; lively ; ate well. Jan, 17th, slept well, ate heartily. Jan. 26th, animal had completely recovered; weight 5120 grams. /?-naphthol orange is, therefore, according to experiment I, poisonous in small doses when administered by the stomach, and suffices to kill a moderately strong dog. The rabbit, experi- ment 2, serves as a control. In contrast to /3-naphthol orange, Cazeneuve and Lepine found the corresponding a-naphthol orange, distinguished from /?-naphthol orange only by the posi- tion of the hydroxyl group, non-poisonous. The /3-color seems almost to show its poisonous action when administered subcu- taneously, but the animal did not succumb to the experiment. Ponceau 4 GB. This color is also known as croceln and brilliant orange. I prepared this color myself from diazobenzene chloride and sodium /9-naphtholsulphonate S. (Schasffer's salt.) It has prob- ably the constitution : — N = N Typical Reactions. — In the pure condition a red crystalline powder that dissolves not very easily in water to a red solution which produces, with hydrochloric acid, a yellowish-brown pre- cipitate, easily soluble to yellowish-red color in alcohol. With sodium hydroxide and ammonium hydroxide, a yellow solution. With ammoniacal copper solution, a dirty, yellowish-broAvn pre- cipitate. Concentrated sulphuric acid dissolves the powder to 124 THE COAL-TAR COLORS. an orange-yellow liquid, which deposits a yellowish-brown pre- cipitate when diluted with water. In acid solution, wool is col- ored orange yellow. Exp. I. — Dog weighing 12400 grams; received, June 19th, 2 grams dissolved in water by the tube. Urine rose-colored. June 20th, 2 grams administered. Urine reddish. June 21st, 2 grams in water. Animal lively ; urine reddish, no blood, no albumin. June 22d, 2 grams. Animal lively ; urine alkaline, no albumin, no phenol. June 23d, 4 grams. Urine normal color, alkaline, turbid, no albumin. June 24th, animal lively, took food. June 27th, 4 grams. June 28th, urine normal color, free from albumin. In a second investigation a dog weighing 8500 grams received for an entire month i gram daily by the cesophageal tube. Urine remained uncolored, animal lively, with undisturbed appetite. The loss of weight, 200 grams in thirty days, need not be considered. This color can be regarded as non-poisonous. Archil-substitute. Naphthion red (now obsolete). This color is prepared from diazotized^-nitraniline and naph- thionic acid and has, therefore, the constitution : — N = n/\X \ NO2 My preparation was obtained from the Aniline Manufacturing Company of Berlin. It was in the form of a red liquid which contained 8.2 per cent, of the color. Typical Reactions. — The color has the form of a brown paste soluble in water to a red-brown color, which solution gives with hydrochloric acid a bluish-red precipitate which is soluble in water and in 96 per cent, alcohol to a red brown. Acetic acid produces a reddish-brown solution. Sodium hydroxide produces a bluish-red precipitate difficultly soluble in water but easily OBSERVATIONS ON ANIMALS. I25 soluble in alcohol to a brownish-red liquid. Ammonium hy- droxide produces a brownish-red solution. Ammoniacal copper solution produces a dirty red precipitate which is soluble in hot water. The paste dissolves in concentrated sulphuric acid to a fuchsin-red solution, which, on dilution with water, gives a red- brown precipitate. It colors wool, in acid solution, archil red. Exp. I. — December 24th and 26th, dog weighing 3810 grams, urine weakly alkaline, some albumin, no mucin. Dec. 27th, 20 c.c. of the solution equals 1.64 grams of the color administered with pep- tone. Tendency to vomit, but no actual vomiting. Urine normal, nearly colorless, slightly alkaline, traces of albumin. No character- istic changes with acids or alkalies, or concentrated sulphuric acid. Dec. 28th, 20 c.c. of the solution with peptone. Urine as above, animal lively. Dec. 30th, 40 c.c. of the solution equals 3.28 grams of the color. Dec. 31st, animal lively, took food; urine as above; weight 3980 grams, consequently a gain of 170 grams in seven days, Jan. 1st, 1889, urine uncolored, some albumin, much sulphates. Jan. 2d, 50 c.c. of the solution equals 4.1 grams of the color. Urine alka- line, otherwise, as above, no color. Jan. 3d, urine gives a rose color to filter paper ; alkaline, with very little albumin, dyes wool when acidified ; animal lively ; experiment relinquished. In a second investigation, a dog weighing 4500 grams received daily for one month 10 c.c. of the color solution, which equals .82 gram of the color, — therefore, altogether, 24 grams, which showed the same results as experiment No. i, except that the urine remained uncolored. Exp. 2. — Dog weighing 4980 grams, on Jan. 2d showed urine oi normal color, very little albumin, and received 10 c.c. of the color subcutaneously, which equals .82 gram, of the color. Jan. 3d, urine reddish, no injection. Jan. 4th, urine reddish, traces of albumin. 10 c.c. of the solution administered on left side of the back. Jan. 5th, urine reddish, hardly any albumin, much sulphates ; animal lively, no abscesses. Jan. 6th to 7th, no abscesses, animal lively ; little albumin. Jan. Sth, animal normal ; urine uncolored ; little albumin. Jan. 9th, food taken; no abscesses; 20 c.c. (equals 1.64 grams) injected in two places on the back. Jan. loth, no food taken ; con- 126 THE COAL-TAR COLORS. junctiva not colored; urine reddish; no albumin. Jan. nth, no abscesses ; urine uncolored, little albumin. Jan. 12th, urine colorless, little albumin. Jan. 14th, weight 4950 grams, therefore, no reduction in weight in twelve days; animal lively, no abscesses. Jan 17th, animal lively ; very little albumin. This color, in the doses indicated, must be regarded as not poisonous when administered by the stomach or subcutaneously, in spite of the fact that it contains a nitro-group. Probably, as is the case with naphthol yellow, the action of the nitro-group is ameliorated by the simultaneous presence of a sulphonic group. Chrysoidin. This color is prepared from diazobenzene chloride and 7?i- -diaraidobenzene, and has, therefore, probably, the constitution : N = N ^ NH2HCI NH2 It colors wool and silk without a mordant, and cotton after mordanting, orange. My specimen was obtained from the Ani- line Manufacturing Company of Berlin, and was in the form of a reddish-brown crystalline powder easily soluble in water to a brownish-red liquid. Typical Reactions. — The watery solution produces with hydro- chloric acid a brown gelatinous precipitate easily soluble in water to an orange-yellow liquid. Acetic acid produced no change. Sodium hydroxide and ammonium hydroxide produced orange- brown precipitates difficultly soluble in water, easily in alcohol, to orange-yellow liquids. Ammoniacal copper solution produced a brownish-red precipitate soluble in hot water and insoluble in alcohol. The powder dissolved in concentrated sulphuric acid to a yellowish-brown liquid which by dilution with water became ponceaux. Exp. I. — March 24th and 25th, dog weighing 26600 grams. Urine uncolored, containing albumin. March 25th to 26th, 3 grams by the OBSERVATIONS ON ANIMALS. I 27 tube. March 26th to 27th, urine colored strongly orange-brown ; albu- min distinctly present. March 29th to 30th, urine slightly colored, animal lively. April ist, 10 grams by the tube. April 2d to 5th, urine colored very strong brown; little albumin. April 6th to 7th, 10 grams administered. Animal took food, did not vomit. April 8th to loth, urine dark brown, albumin distinct. In a second investigation, a dog weighing 9500 grams took daily, for one month, i grain of chrysoidin. Animal remained lively ; urine uncolored and free from albumin. It lost during this time about 1200 grams, therefore about one-eighth of its body weight. Exp. 3. — April I2th, dog weighing 58500 grams; urine uncolored, and traces of albumin present. April 13th to 14th, .1 gram subcutane- ously in 10 c.c. of sterilized water. April 15th to 27th, urine uncol- ored, little albumin ; animal hvely ; appetite as usual. April 29th to 30th, .1 gram subcutaneously. May 2d to 3d, animal lively; urine uncolored. May 5th, urine uncolored ; very little albumin. May 8th, .1 gram subcutaneously. May loth, urine normal; no abscesses; appetite good ; weight 4620 grams ; therefore, lost about 1230 grams, or one-fifth its body weight. May 5th, animal normal ; ate well ; urine nearly free from albumin. hijection mto the abdominal cavity. — Dog weighing 4500 grams re- ceived, three times in the course of 10 days, .1 gram of chrysoidin in sterihzed water injected into the abdominal cavity with a sterilized syringe. The urine remained uncolored, but contained some albu- min. The animal, three weeks after termination of the experiment, was entirely well and had good appetite. Chrysoidin produces, according to my investigations, a slight albuminuria and notable reduction of the body-weight, but fur- ther disturbance has not been noted. With large doses intro- duced into the stomach, a portion of the color appears in the urine. In contrast to the experiment with dogs, Blaschko describes a frequently occurring eczema among workmen engaged in the manufacture of the color. To determine if this skin affection is caused by the color itself, or rather by the materials required for its manufacture (especially the ;;/-diamidobenzene might be suspected) requires, I think, further investigation. 128 THE COAL-TAR COLORS. Diphenylamine Orange. This color, known also as acid yellow D, diphenyl orange, orange IV, tropaeolin 00, orange B, aniline yellow, orange G S., new yellow, helioxanthin (?), is produced from diazotized /-amidobenzenesulphonic acid and diphenylamine. The com- mercial article has probably the following constitution : — N = N NaSOg NH It is sodium azodiphenylamine-/-azobenzenesulphonate. The specimen I used was obtained from the Aniline Manufacturing Company of Berlin, and was an orange-yellow powder dissolv- ing in cold water, but not very easily, to an orange-red liquid. Typical Reactions. — The watery solution produced with hydro- chloric acid a reddish-violet precipitate which was difficultly soluble in water, but easily soluble in 96 per cent, alcohol and produced an orange-red liquid. Sodium hydroxide produced a yolk-of-egg color and dissolved with difficulty in water to the same color; in 96 per cent, alcohol, to an orange-yellow color. Ammonium produced an orange precipitate tolerably easily solu- ble in excess of the precipitants. Ammoniacal copper solution produced a yellow precipitate which dissolved in hot water to a brown liquid and reprecipitated on cooling. The powder dis- solves in concentrated sulphuric acid to a bluish-violet solution which on dilution with water gives a violet precipitate that is soluble in excess of water to a reddish-violet liquid. In acid solution wool is colored orange-yellow. The color serves as an indicator in titration, since in the presence of small amounts of free acid, except carbonic, it is changed to red. Exp. I. — January i6th-i8th, dog weighing 27350 grams; little albumin in urine. January 19th, 5 grams in peptone by the tube. Urine on standing became dark colored from the surface downward ; albumin present, sulphates abundant, reaction alkaline ; animal was OBSERVATIONS ON ANIMALS. 1 29 lively and took food. January 20th, urine almost black, otherwise as the day before. January 21st, 5 grams administered. Urine alkahne, almost black. When treated with strong hydrochloric acid and dis- tilled, it gives only traces of phenol. The original urine gives with fer- ric chloride no characteristic reaction. Addition of hydrochloric acid produces a flocculent precipitate insoluble in water, but soluble in hot alcohol. The filtrate from the acidulated urine gives a distinct albu- min reaction. January 23d, the substance precipitable by the addi- tion of acid was no longer present ; albumin abundant, 3 grams ad- ministered. January 24th, precipitable substance still missing ; urine almost colorless; albumin scanty. January 25th, urine very dark, gives precipitate with hydrochloric acid ; albumin scanty. January 26th, urine uncolored, albumin scanty. January 27th, same. Janu- ary 28th, 10 grams administered; urine abundant, strongly black, contains albumin and sulphates, alkahne. January 29th and 30th, urine dark colored, albumin abundant ; very little food taken. Janu- ary 31st, much albumin ; weight, 2635 grams ; therefore, 1000 grams lost, — that is to say, 1-27 of the body weight in fourteen days. Feb- ruary 2d, fifteen grams administered ; urine deep color ; albumin abundant ; animal lively. February 3d, urine dark brown ; albumin distinct ; appetite good. February 7th, urine almost normal in color ; animal lively. Exp. 2. — January 15th to i8th, dog weighing 9730 grams, showing but little albumin in the urine. January 19th, 3 grams in peptone. January 21st, 3 grams. January 22d, no administration ; animal lively. January 23d, 2 grams ; food taken. January 27th, animal lively, took food ; 3 grams of the color administered. January 28th to 30th, 3 grams each day ; animal lively. January 31st, 3 grams, animal took food and was lively ; weight, 9820 grams. Animal received, from February 2d to 15th, daily, 3 grams ; urine contained unchanged color and albumin ; animal remained lively. Exp. J. — March 20th, dog weighing 5450 grams ; albumin dis- tinctly present. March 21st to 22d, urine colorless, contained distinct amount of albumin ; ,1 gram administered subcutaneously. March 22d to 23d, no abscesses ; urine uncolored ; animal lively. March 24th, .1 gram subcutaneously ; urine uncolored, little albumin. March 25th, urine uncolored, contained but httle albumin ; exhibited no change on addition of hydrochloric acid or sodium hydroxide. March 26th, no abscess ; animal took food. March 29th to 30th, no abscesses, urine uncolored. March 31st to April 4th, .1 gram sub- II 130 THE COAL-TAR COLORS. cutaneously ; took food. April 4th, animal lively ; weight, 5220 grams ; therefore, lost 230 grams in fourteen days, or 1-24 of the body weight. April 12th, no abscesses; animal lively. According to the above investigations, diphenylamine orange causes albuminuria, but further disturbances did not appear dur- ing the several weeks' observations on the animals used. Metanil Yellow. This color, also known as orange MN, is produced by diazo- tizing w-amidobenzenesulphonic acid and the conjugation of the resulting compound with diphenylamine. It has, therefore, probably, the constitution : — N =- N /X /\ /X NaSO 3 ^ ^ NH The commercial form is the sodium azodiphenylamine-;^/- azobenzenesulphonate. My specimen was obtained from the Aniline Manufacturing Company, of Berlin, and exhibited the form of a yellowish-brown powder, smelling strongly of diphe- nylamine. Typical Reactions. — It dissolves in water to a yellowish solu- tion. Hydrochloric acid produced a violet precipitate, which slowly dissolved to a fuchsin-red liquid in an excess of hydro- chloric acid or water. Sodium hydroxide does not immediately affect the watery solution. In time a yellow crystalline precipi- tate separates, which is soluble in warm water to an orange-red liquid. The dried color dissolves in concentrated sulphuric acid to a violet solution, which is changed to a fuchsin red by dilu- tion with water. Ammoniacal copper solution produces, in watery solution, a heavy, flocculent, pale-yellow precipitate diffi- cultly soluble in water. For purification the color was dissolved in water, filtered, and separated by the addition of sodium acetate. The yellow mass OBSERVATIONS ON ANIMALS. 131 was freed from the adherent licjuid by the filter pump and dis- solved in hot alcohol, in which it is difficultly soluble, and ob- tained from this in the form of yellow crystals. The material used for the experiments was almost pure, as the following ana- lytical statement shows : 0.4895 gram of the color dried in 105° gave 0.084 sodium sulphate. Sodium, required, 6.1 ; found, 5.6. Like diphenylamine orange, this color, in acidified solution, dyes wool orange-yellow. Exp. I. — Dog weighing 11600 grams. April 2d, urine almost free from albumin. April 4th, 10 grams by the tube ; animal vomited and did not take food. April 5th, 10 grams ; animal vomited and did not take food. April 7th, animal very miserable and did not take food ; labored respirations. April 8th, died during the night of the 7th day. Post-mortem : — Body stiff, skin not colored, mucous membrane yellowish, intestines pale, not stained ; kidneys pale, not stained ; liver red, contained much unchanged color since it becomes red with concentrated sulphuric acid ; much unchanged color in the stomach ; lungs contained a circumscribed focus in which tubercle bacilli were recognizable, but were otherwise normal. The deposit was on the anterior surface of the lower lobe of the right lung. The animal took, in the course of four days, 20 grams of the color, there- fore, 1.7 grams per kilo of the body weight, and was killed by this dose. Exp. 2. — March 19th, dog weighing 11250 grams. Albumin dis- tinctly present. March 21st, i gram. Urine colorless, albumin distinct. March 22d, urine colorless, developed dark color from the surface ; albumin distinct. March 25th, urine in thin layers, orange- yellow, became bluish-violet with hydrochloric acid, and orange-red with sodium hydroxide. Animal lively ; conjunctiva not tinged. March 26th, 10 grams. About one hour after the administration strong vomiting occurred. March 27th, very little food taken ; urine dirty greenish yellow. March 28th to 29th, urine normal in color, albumin distinct. April ist, 5 grams administered. Animal took little food and died on the night of April ist. Weight 8750 grams. Post-mortem ; skin and subcutaneous cellular tissue, serous membranes and intestines, and contents of intestines yellow. Intestinal contents became colored ruby-red with concentrated sulphuric acid, and there- fore, contained the unchanged color. The liver was hyperasmic, dark red, and gave the reaction with concentrated sulphuric acid. 132 THE COAL-TAR COLORS. Kidneys were deep yellow ; conjunctiva yellow. Contents of the bladder were orange-yellow and were turned red by concentrated sulphuric acid, and contained, therefore, the unchanged color. This animal received in the course of twelve days twenty-one grams of the color, or 0.53 gram per kilo of the body weight. This dose is fatal. Exp. J. — Dog weighing 5220, grams, on April 3d, had traces of albumin in the urine. April 6th, .1 gram in 10 c.c. of sterilized water administered subcutaneously. Animal trembled a great deal. April 9th, .15 gram subcutaneously at two points. Animal trembled, but ate freely. April nth, .15 gram. No abscesses, animal livelier, trembling no longer observed : urine contained traces of albumin. April 14th, weighed 4790 grams, was lively and took food. Metanil yellow must be considered poisonous when admin- istered by the stomach, from the indication of Experiments i and 2. The lethal dose, which is determined by Experiment 2, is 0.53 gram per kilo of the body-weight. The isomeric diphenylamine orange is, on the other hand, non-poisonous. Azarin S. Azarin S is obtained by the diazotizing of amidodichlor- phenol, joining the compound with /?-naphthol, and treating the resulting color with ammonium acid sulphite. The operation, therefore, takes place in two steps : one, the production of the azo-color; secondly, addition of the ammonium acid sulphite. For the product of this reaction, the following formula is gener- ally assumed.* CI2 CeH^HO NH — NCioHgHO NH4SO3 The color itself is insoluble, but becomes soluble through the addition of the acid sulphite. If the azarin S so prepared is printed together with aluminum acetate on cotton goods, and ^ [The formula for azarin is given differently by different authorities. — Trans.] OBSERVATIONS ON ANIMALS. 1 33 the fabric treated • with warm water in the presence of an alkali or an acid, the material is split up into a soluble sul- phite, or free sulphurous acid, and an insoluble dichloramido- phenolazo-/5-naphthol. The latter is fixed upon the fibre as a color. My preparation, for which I am indebted to the kindness of Mr. V. Gerichten, was manufactured by Meister, Lucius & Briining. It was a thin, yellowish orange, strongly acid paste, smelling of sulphurous acid. It was not entirely soluble in water. Typical Reactions. — The watery solution produced with hydro- chloric acid a yellow precipitate which dissolved in alcohol with a yellow color. Ammonium hydroxide produced a brown-red solution : sodium hydroxide, a bluish-violet solution, which by warming became reddish-violet and retained this color on cool- ing. Concentrated sulphuric acid produced a dark-red solution, sulphurous acid escaping. On diluting the solution with water a brown solution appeared which was easily soluble in alcohol to a brown color. Ammoniacal copper solution produced a violet precipitate appearing in thin layers as reddish. Exp. I. — A large dog weighing 25600 grams received, in the course of twenty-five days, a total of thirty-five grams of the color suspended in water administered by the tube. The urine was colored a weak yellow and contained a distinct amount of albumin. Sulphurous acid was produced on adding hydrochloric acid to the urine. The appe- tite of the animal was not diminished. In a second experiment, a dog weighing 10,300 received, in the course of twenty days, twenty grams of the color administered in the same manner. Results the same as in experiment i. Exp. 3. — A dog weighing 4700 grams received, in the course of eight days, three injections of i gram each of the azarin paste suspended in IOC. c. of water inserted under the skin of the back. During the period of observation (three weeks) no abscess appeared at the point of injection, nor was there albumin or abnormal coloring matter found in the urine. The appetite was unimpaired. Another dog received, on May 15th, 5 c.c. of the paste in 5 c.c. of sterilized water, therefore altogether 10 c.c. of liquid, which was injected by means of the Koch syringe into the ab- dominal cavity. On the following day the animal had no appe- 134 THE COAL-TAR COLORS. tite, but the urine remained uncolored. On the third day the animal seemed very miserable and took no food. There was a little albumin in the urine. The day after, the animal was found dead in its cage. Post-mortem showed the peritoneum and the inner surface of the intestines tinged in spots with a red color. The small intestines were adherent for a considerable distance to the peritoneum. The cause of death was considered to be peri- tonitis without effusion. The result of this post-mortem is of much interest. The red spots consisted, as was determined by chemical analysis, of the azo-color, which is the basis of the azarin S. Consequently, in the peritoneal cavity the same splitting up of the azarin S had occurred which takes place when it is attached to textiles. Administered by the stomach, the azarin S is harmless. DISAZO-COLORS. The following is a summary of the results obtained \^th the disazo-colors submitted to test by me, viz : — Fast brown G, woolblack, naphthol black P, Congo red, azo-blue, chrysamine R. All these proved to be non-poisonous, except that naphthol black P had an injurious effect when administered subcutane- ously. PRIMARY DISAZO-COLORS. Fast Brown G. This color is produced by diazotizing two molecules of/-amido- benzenesulphonicacid and joining a molecule of a-naphthol. It has the constitution : — NaSO., NaSOa N=N N=N I I C,oH,HO It is sodium a-naphtholdisazo-/-azobenzenesulphonate. The PRIMARY DISAZO-COLORS. 1 35 specimen I employed was obtained from the Aniline Manu- facturing Company of Berlin. Typical Eeactions. — A brown powder producing a red-brown solution in water, which gives with strong hydrochloric acid a violet precipitate, dissolving to a violet solution in hydrochloric acid, and in water to a brown solution. Sodium hydroxide and ammonium hydroxide produce a cherry-red liquid. Ammoniacal copper solution produces in concentrated solution a cherry-red precipitate easily soluble in water. The powder dissolves in concentrated sulphuric acid to a red-violet liquid which turns violet-yellow on boiling. The reddish-violet liquid, on being diluted with water, turns cherry-red. Exp. I. — Dog weighing 9630 grams, showing but litde albumin in the urine, received on January 19th three grams by the tube. January 20th, urine contained but little albumin and was almost normal in color ; addition of sodium hydroxide produced a bluish-red color ; therefore, traces of the administered color were present. The urine, acidulated with acetic acid, dyed wool red-brown. January 21st, three grams given. January 22d, diarrhoea; urine red but not bloody; albumin slight ; sodium hydroxide produces a bluish-red color, and the urine, acidulated with acetic acid, easily dyes yarn. January 23d, urine but little colored, becomes a weak bluish-red with sodium, hydroxide ; two grams administered. January 24th, urine strongly red, little albumin. January 25th, urine normal in color, traces of albumin. January 26th to 29th, urine normal in color, traces of albumin, January 30th, urine almost free from albumin ; five grams administered January 31st, marked diarrhoea; urine hardly colored, and gives with sodium hydroxide a weak fuchsin red, little albumin ; weight, 8820 grams. February 3d, ten grams of the color administered. February 4th, severe diarrhoea ; urine contained unchanged color ; animal did not take food. February 5th, urine same as day before. February 7th, urine colorless ; little albumin ; diarrhoea ; some food taken. February 12th, animal normal; albumin slight. In a second experiment a dog weighing 5900 grams received during an entire month, daily, two grams of the color. After six days a slight diarrhoea was produced, which continued almost during the month. Appetite was diminished, and there was lost about one-fifth of the original weight. 136 THE COAL-TAR COLORS. According to these experiments this color in continuous, though slight, doses, or in larger doses, but less frequently, produces diarrhoea, anorexia, and emaciation. Exp. J. — A dog weighing 6730 grams, not showing any albumin- uria, received on March 5th o.i gram of the color in 10 c. c. of luke- warm water subcutaneously. Urine was uncolored and contained little albumin. March 6th, no abscess ; urine uncolored, no albumin ; condition continued the same up to March 12th, when o.i gram was administered subcutaneously; March 13th, no abscess. March 14th, O.I gram subcutaneously; animal continued lively and took food. March 14th to i8th, no abscess ; urine uncolored, no albumin. March 20th, animal lively ; weight, 6450 grams. March 23d, no abscess ; urine almost uncolored, and albumin slight ; no change with sodium hydroxide or hydrochloric acid. March 26th, 0.1 gram subcutan- eously. March 28th to April loth, animal lively ; no abscess. Repeated doses of .1 gram subcutaneously did not unfavorably affect the health of the animal. SECONDARY DISAZO-COLORS. Wool Black. This color is produced by the action of diazotized amidoazo- benzenedisulphonic acid on /-tolyl-/S-amidonaphthalene, and has the following formula : — C6H^(NaS03)N = NCgH3(NaS03)N = NCioH6(NH)(CH3)CeH^. It may be termed sodium /-tolyl-/5-amidonaphthalene-azoami- doazobenzenedisulphonate. The specimen I used was from the Aniline Manufacturing Company of Berlin. Typical Reactions. — Dark-blue powder producing bluish-violet in water, which gives with hydrochloric acid a reddish-violet precipitate soluble in water. Ammonium hydroxide gives a bluish-violet solution. With ammoniacal copper solution, a bluish-violet precipitate difficultly soluble in water. The powder dissolves in concentrated sulphuric acid to a blue solution which gives a brown precipitate on dilution with water : this is decom- posed on boiling. By boiling with dilute sulphuric acid the wool-black, according to Witt, is decomposed to tolunaphtazin SECONDARY DISAZO COLORS. 1 37 and amidoazobenzenedisulphonic acid. The color in acid bath dyes wool bluish black. ' Exp. I. — Dog weighing 29940 grams, showing a weak alkaline urine, with little albumin, received, December 28th, 5 grams of the color in peptone, by the tube. The urine remained normal color, was neutral, contained a little albumin, much sulphates, and produced with acids and alkalies, even on boiling with concentrated sulphuric and hydrochloric acids, no characteristic reaction. December 29th, 5 grams of the color administered. Animal remained lively ; urine normal in color. December 30th, five grams of the color admin- istered. Urine normal in color, animal lively ; albumin and sulphates as before. Dec. 31st to Jan. ist, urine uncolored. Jan. 2d, ten grams by the tube ; urine intensely dark blue, in thick layers black ; acidified, it colors wool bluish-black; it contained albumin, as was demonstrated after precipitation and filtration from the color. Jan. 4th, urine colorless, contained very little albumin. Ten grams ad- ministered. Jan. 5th, urine intensely dark blue ; in thick layers, almost black. The color was separated from the urine by the addition of sodium acetate. Jan. 6th to 7th, animal took food ; urine colorless, darkened from the surface downward on standing ; reaction alkaline; albumin distinct, sulphates abundant. Jan, 7th to 12th, animal lively. Jan. 13th to 19th, albumin distinctly present; animal lively ; appetite good. Jan. 20th, albumin slight. Exp. 2. — Dog weighing 3520 grams, urine of which was colorless and free from albumin, received, Jan. 21st, .25 gram of the color in 10 c.c. of lukewarm water under the skin of the back. Jan. 22d, rectal temperature 39.5°; urine uncolored; no abscess; animal lively and took food. Jan. 23d, .25 gram administered; animal lively ; no abscess. Jan. 24th, .25 gram administered. Urine uncol- ored ; traces of albumin. Jan. 26th to 27th, urine uncolored, tem- perature normal. Jan. 28th, abscess on the right side of the back ; 0.25 gram administered subcutaneously. Jan. 29th, urine colorless, little albumin. Jan. 30th, urine colorless, alkaline, little albumin ; abscess reduced in extent. Wool black is non-poisonous both by gastric and by subcuta- neous administration. 12 138 THE COAL-TAR COLORS. Naphthol Black P. This color is produced by the diazotizing /S'-amidonaphtha- lenedisulphonic acid G, and conjugation with a-amidonaph- thalene. The a-azoamidonaphthalene-/5-amidonaphthalenedi- sulphonic acid thus produced is diazotized again and united to /5-naphtholdisulphonic acid (R-salt). According to this synthesis the color has the following formula : — C,oH5(NaS03)N z.^ NqoHgN = NCioH^(NaS03)2HO. and is the sodium amidoazonaphthalenedisulphonateazo-/?- naphtholdisulphonate R. I am indebted to the firm of L. Cassella& Co., of Frank, o. M. for the specimens I used. Like wool black, it dyes wool bluish-black in acid bath. Typical Reaction. — It appears in the form of a bluish-black powder dissolving to a dark blue-violet solution in water. The watery solution becomes a blue-violet by the action of hydro- chloric acid, acetic acid, sodium hydroxide, and ammonium hydroxide. Ammoniacal copper solution produces a fuchsin-red liquid but no precipitate. Barium chloride and ferric chloride produce bluish-violet precipitates difficultly soluble in water. The powder dissolves in concentrated sulphuric acid to a dirty- green solution, which becomes blue on dilution with water. Exp. I. — Dog weighing 26730 grams, the urine of which contained little albumin, received, March 3d, 3 grams by the tube. Urine remained almost uncolored, and showed but little albumin. No appreciable change was produced by either hydrochloric acid or sodium hydroxide. March 4th to 5th, 3 grams by the tube. Albumin distinct, urine uncolored. Faeces colored blue. March 5th to 6th, 5 grams, urine colored a weak, reddish-violet, becomes fuchsin-red with hydrochloric acid. March 6th to 8th, albumin slight ; animal lively, took food freely, March 9th to loth, urine dirty,, bluish-red, colored orange-red with hydrochloric acid ; bluish-red with sodium hydroxide ; the acidified liquid dyes wool. March 12th, 10 grams administered. Animal took food; urine blue. March 13th, urine as before, litde albumin. March 14th, 20 grams administered. Rather much albu- SECONDARY DISAZO-COLORS. 1 39 min ; animal lively; took food. "March 15th, urine bluish, albumin distinct. March 19th, urine colorless, albumin slight. March 21st, weight, 26,620 grams, A second dog weighing 4500 grams received during one month, daily, one gram of the color. It remained entirely well with good appetite. Exp. J. — Dog weighing 3200 grams, of which the urine was color- less and free from albumin, received, March 5th, o.i gram subcuta- neously, dissolved in 10 c.c. of lukewarm water, introduced under the skin of the back on the right side. March 6th, urine scanty, uncolored, no albumin ; no abscess. March 7th, o.i gram subcutaneously. Animal took but little food. March 8th, no abscess ; urine uncolored, no albumin, took no food. March 9th, died during the preceding night. Weight, 2250 grams. Post-mortem showed no abscess, no induration at the point of injection ; much unchanged color under the skin at the point of injection, which was free from microorganisms. Gelatin plates inoculated with the color taken from the point of injection remained sterile during nine days. The body was not yet rigid, but much emaciated. The mucous membranes were of normal color ; the intestines were pale; mesenteric vessels were much injected. The liver, pancreas, kidneys, and lungs were strongly hyperasmic ; no exudates were noted. Exp. 4. — Dog weighing 3860 grams, which had been used for another experiment and very much emaciated, the urine being un- colored and containing a little albumin, received, March 12th, 0.1 gram subcutaneously in 10 c. c. of water. March 13th, no abscess; animal miserable ; urine scanty, almost uncolored, no color change with sodium hydroxide, acetic acid, or hydrochloric acid ; albumin dis- tinct; .1 gram of the color subcutaneously. March 14th, 0.1 gram subcutaneously. Urine colorless ; no abscess. March i6th, urine colorless ; albumin very distinct ; animal took food but was very miserable. March 19th, no abscess ; animal very much emaciated ; albumin distinct. March 21st, took food abundantly. Weight, 3887 grams. March 25th, animal very thin ; took food, and was killed by hydrogen cyanide. Post-mortem. The subcutaneous cellular tissue beneath the point at which the injections were made was deep bluish-red, and the muscles showed the same color. The liver and other glands were strongly hypersemic and hypertrophied, and the intestines were slightly bluish-red. The conjunctiva and mucous membrane of mouth were not colored. 140 THE COAL-TAR COLORS. This color is harmless when administered by the stomach, but poisonous subcutaneously. DISAZO-COLORS OF THE CONGO GROUP. Congo Red. This color is obtained by diazotizing benzidine, and uniting the tetrazo-compound with two molecules of a-amidonaph- thalenesulphonic acid. Its constitutional formula is, therefore, as follows : — N = N NH2 NaSOg N NH2 NaSOg The commercial article is sodium benzidinedisazo-a-amidonaph- thalenesulphonate-a-amidonaphthalenesulphonate. My specimen was obtained from the Aniline Manufacturing Company of Berlin. Typical Reaction. — It is a red powder, producing with water a blue solution in which hydrochloric and acetic acids pro- duce blue precipitates scarcely soluble in hot water. Sodium hydroxide produces in concentrated solution a reddish-brown color but slightly soluble in water. Ammoniacal copper solution produces a gelatinous red precipitate, soluble in excess of water with a red color. The powder dissolves in concentrated sul- phuric acid to a blue solution, which on dilution with water gives a blue precipitate. It colors cotton and wool without a mordant. Exp. J. — Dog weighing 7300 grams, showing very slight albumin- uria, received, December i8th, two grams of the Congo red dissolved DISAZO COLORS OF THE CONGO GROUP. I41 in peptone administered by the tube. Animal lively ; urine entirely normal in color. December 19th, two grams of the color administered. Urine pale, feebly alkaline, traces of albumin, no sugar. December 20th, two grams of the color administered. Urine a weak red color, no change on addition of acids, becomes yellow with sodium hydrox- ide ; little albumin. December 21st, three grams of the color. Ani- mal lively ; urine somewhat reddish ; cotton could not be colored with the urine without previous preparation, and the dyed stuff turned red on treatment with acids ; little albumin. December 23d to 26th, ani- mal lively ; urine weak reddish in color and gives a reddish sediment, probably Congo red. December 27th, five grams in peptone. Ani- mal lively ; urine almost uncolored, feebly alkaline; some albumin. December 28th, ten grams of Congo red ; but little albumin in the urine ; cotton dyed easily. December 30th, ten grams. Animal took but little food, but was otherwise comfortable ; urine but little colored, feebly alkaline, little albumin, sulphates present ; weight, 6980 grams; lost, therefore, 320 grams in sixteen days. December 31st, animal lively; experiment discontinued. January 15th, animal in good con- dition. A second dog weighing 4300 grams received during one month daily one gram of Congo red with the tube. It remained entirely well. Exp. 3. — Dog weighing 4970 grams, showing traces of albumin in urine, received, January 5th, 1889.. .25 gram of Congo red dissolved in 10 c.c. of water introduced under the skin on the right side of the back. January 6th, urine scarcely colored, almost free from albumin. January 7th, .25 gram injected similarly; urine uncolored, alkaline, but little albumin ; animal seemed weak. January 8th, took but little food ; urine uncolored ; no abscess. January 9th, urine uncolored, and but little food taken ; .25 gram introduced under the skin of the back on the left side. Abscess appeared on the abdomen to the right of the mesial line. January loth, but little food taken ; urine un- colored ; .25 gram administered subcutaneously under the skin of the left side of the back. Large abscess to the left of the linea alba, January nth, animal very weak. Urine almost uncolored and con- tained little albumin. A large abscess on the right side of the abdo- men was opened and about 15 c.c. of a blood-red liquid was dis- charged in which fatty globules could be seen by the naked eye. The liquid coagulated in about ten minutes, and after suitable dilution showed the oxyhasmoglobin bands, though very weakly. Acids made 142 THE COAL-TAR COLORS. the liquids intensely blue, and it, therefore, consisted in large part of unchanged non-absorbed color. Microscope showed fatty globules, red blood corpuscles, some of which were normally formed and some shriveled. Pus cells were also present, but microbes colored by Gramm's method were not found. January 12th, animal very weak and melancholy. Weight, 4300 grams, therefore lost 670 grams in eight days. January 13th to 14th, the abscess which opened on Janu- ary nth spontaneously discharged a red liquid which contained much Congo red, as was indicated by the bluing by acids. The opened abscess on the left side seemed to have been absorbed. Rectal tem- perature 39.5°; .25 gram administered. January i6th, animal very miserable, did not eat ; rectal temperature 39-5°; the opened abscess seemed about to close. January i8th, rectal temperature 39.2°; ani- mal was uncomfortable, ate but little. January 22d, took some food ; cross and miserable ; rectal temperature 40.5°. January 24th, weak and cross ; took food. January 29th, one abscess opened spontane- ously and discharged unchanged color mingled with some pus. Animal took food but was very weak. February 5th, animal again lively, took food. The abscess over the abdomen was doubtless a hypostatic abscess from the material introduced at the point of injec- tion. According to experiments i and 2, Congo red is, after long- continued administration by the stomach, harmless. The dis- turbances which ensued on subcutaneous injection were prob- ably dependent upon an invasion of putrefactive bacilli and had no direct relation to the color. DISAZO-COLORS OF THE CONGO GROUP. 143 Azo-blue. This coJor is produced by diazotizing one molecule of ortho- toluidine and joining the tetrazo-compound so formed to two molecules of a-naphtholmonosulphonic acid (N. W.). The con- stitutional formula is as follows: — N = CH, CH. N = N HO NaSO, HO NaSO. and the color is, therefore, sodium tolidinedisazo-a-naphthol- monosulphonate (N. W.) a-naphtholmonosulphonate (N. W.). The specimen used was obtained from the Aniline Manufacturing Company of Berlin. The color dyes cotton, in alkaline bath, grayish violet. Typical Reactions. — It is a bluish-black powder tolerably easily soluble in water to a red-violet liquid. The watery solution produces with hydrochloric acid a reddish-violet precipitate easily soluble in water and alcohol. Sodium hydroxide produces a cherry-red liquid. Concentrated sulphuric acid produces in the solution a blue precipitate that is soluble in excess of acid to an indigo-blue liquid. The powder dissolves in concentrated sulphuric acid to an indigo -blue liquid which becomes turbid on the addition of water from the separation of a violet precipitate. The precipitate is soluble in water to a violet solution. The solution of the color in concentrated sulphuric acid is decom- posed by boiling, becoming brown. Ammoniacal copper solu- tion produces a cherry-red precipitate that is difficultly soluble in water. 144 THE COAL-TAR COLORS. Exp. I. — Dog weighing 8450 grams, urine of which was pale and contained but little albumin, received, January 8th, two grams dis- solved in peptone administered by the tube. January 29th, animal was lively, took food ; urine was uncolored. Sodium hydroxide pro- duced a transient green color; albumin doubtful. January loth, two grams by the tube. Urine uncolored, but had a violet sheen ; strongly alkaline ; little albumin. Sodium hydroxide and ammonium hydroxide produced a transient greenish tint. No characteristic re- action with ferric chloride. January nth, five grams by the tube; urine colorless ; little albumin. Boiling with concentrated sulphuric acid, but not with dilute acetic acid, produces a distinct bluish black and dark color. It yields to ether a bluish red substance. The dis- tillate was free from phenol. January 12th, eight grams adminis- tered. Urine abundant, somewhat bluish violet. Animal lively. Urine contained but little albumin, and did not produce alkahne copper solution. January 13th to 14th, no administration. Urine colorless. January 15th, urine colorless. Five grams of the color. January i6th, urine colorless, little albumin. January i8th, urine colorless, little albumin. Five grams administered. January 20th, urine colorless, little albumin. Weight, 8490 grams. Exp. 2. — Another dog weighing 4700 grams received during one month one and a half grams daily by means of the tube. Animal remained well, with good appetite. A slight amount of albumin made its appearance in the urine. Exp. 3. — Dog weighing 4600 grams, showing normal urine, re- ceived, January 29th, .20 gram in 10 c. c. of water subcutaneously on the left side of the back. January 30th, abscess appeared at the left side ; .20 gram given in 10 c. c. of water subcutaneously on the right side of the back. January 31st, abscess on the left side opened, and discharged a violet gelatinous mass with only a small amount of blood. The color was the unchanged azo-blue. The pus contained numerous pus corpuscles and large quantities of putrefactive bacilli. The urine was unchanged in color and contained a little albumin. Weight, 4580 grams. February 3d, dog ate and was more lively. February 7th, .20 gram under the skin of the abdomen with a care- fully sterilized syringe after thorough disinfection of the parts in- jected. February loth, no abscess; animal lively. February 15th, no abscess. February 24th, ammal lively, no abscess. Azo-blue is harmless, both when administered by the stomach and subcutaneously. Disturbances produced by the subcutan- DISAZO-COLORS OF THE CONGO GROUP. 145 eous method were ascribable to the introduction of putrefactive bacilli. Chrysamin R. This color is produced by diazotizing one molecule of o-toli- dine in conjugation with two molecules of salicylic acid. The constitutional formula is as follows : — HO N -= N CH. NaCO. CH. N N NaCO. HO The color is, therefore, sodium orthotolidinedisazosalicylate- salicylate. The sample was obtained from the Aniline Man- ufacturing Company of Berlin. Typical Reactions. — It was a brownish yellow powder, and produced a brown solution in water. This solution gave with hydrochloric acid a gelatinous, brown precipitate which was difficultly soluble in water, more easily in alcohol, to a brown color. Acetic acid gives a brown flocculent precipitate. Sodium hydroxide gives a gelatinous, reddish brown precipitate soluble in water to a red-brown color. Ammonium hydroxide gives a red-brown solution. Ammoniacal copper solution gives a gela- tinous, red-brown precipitate difficultly soluble in water. The powder dissolves in concentrated sulphuric acid to a red-violet liquid which on dilution with water deposits a brownish flocculi. Colors cotton, in alkaline bath, yellow. Exp. 7. — Dog weighing 9230 grams, showing normally colored urine, alkaline, very little albumin, and plenty of sulphates, received, on January 3d, five grams of chrysamin in peptone by the tube. Urine was alkaline yellowish, dyeing of cotton easily performed; very little 146 THE COAL-TAR COLORS. albumin. January 4th, five grams of the color administered. Jan- uary 5th, urine yellowish, became red by sodium hydroxide ; diar- rhoea ; animal took food. January 6th to 7th, animal lively ; slight diarrhoea ; urine almost uncolored, albumin slight, sulphates abund- ant, alkaline. January 7th, one gram of the color. Urine slightly colored, contained distinct amount of albumin. January 8th, urine slightly colored, some albumin. January 9th, one gram administered. Animal lively. January loth, two grams administered. Animal lively; wandered about freely the whole day. January nth, two grams administered. Animal lively. January 12th, three grams of the color. January 13th, animal lively, took food. January 14th, weight, 9600 grams; therefore, a gain of 370 grams in 12 days. January 15th, lively. Three grams of the color administered. Jan- uary 1 6th to 20th, albumin slight, animal lively, took food. In a second experiment, an animal weighing 11,300 grams took in the course of 10 days three doses of seven grams each of the color by means of the tube. Urine was yellowish in color, and contained very little albumin. Animal remained lively even 14 days after the administration. Exp, J. — A dog weighing 3680 grams, urine of which ^as un- colored and contained traces of albumin, received, January loth, .25 gram of the color in 10 c. c. of lukewarm water subcutaneously. Urine was neutral, somewhat yellowish, albumin slight. January nth, animal took no food; no abscess; dyeing of cotton did not suc- ceed ; .25 gram injected. January 12th, animal weak, no abscess; urine very slightly colored ; albumin slight; .25 gram was injected. January 13th, albumin slight. January 14th, animal melancholy; no injection ; two abscesses on the back ; 40° rectal temperature. January 15th, .25 gram subcutaneously. Urine weakly yellow; al- bumin distinct; does not color cotton. January i6th, no injection, animal cross ; temperature 39.5° ; took little food. One of the abscess- es of the back opened spontaneously and discharged a yellow liquid (chrysamin). January 17th, animal cross ; rectal temperature 39.5°; abscess as above. January i8th, abscess discharged but little color. January 19th to 21st, temperature 39.5°; cross; had taken little food. There seemed to be a new abscess forming, January 22d, ate but little. The abscesses, which were opened with a knife, discharged about 20 c, c. of a gelatinous mass exhibiting the color of injected dye, and in which the unchanged material itself was found. Bacteria were CONCLUSIONS. 147 not with perfect certainty recognizable in the discharged hquid, and those which are colored by Gramm's method were completely absent. Many fatty globules, only traces of albumin. Weight, 3210 grams. Chryiramin is harmless when taken into the stomach. The abscess produced by subcutaneous administration may be referable to putrefactive organisms, although these were not definitely recognized. CONCLUSIONS. Of the 23 azo-colors subjected to examination only two, metanil yellow and orange II, produce such effects when admin- istered by the stomach that we can consider them poisonous. With dogs, the lethal dose is less than one gram per kilo of the body weight of orange II, and only .53 gram per kilo of metanil yellow. Of the remaining colors some produce vomiting {e.g., Bismarck brown), and others diarrhoea (fast brown, chrysamin R),-and many develop a slight albuminuria. The phenomena produced by subcutaneous administration are not all susceptible of the same interpretation. The abscesses were in some cases (for instance, azo-blue) referable to the invasion of microor- ganisms. Naphthol black P., however, is plainly poisonous when introduced into the subcutaneous cellular tissue. A strik- ing fact is how long, in some cases, the aqueous solution of the color remains unabsorbed in the subcutaneous cellular tissue. Congo red, for instance, in Experiment 3 could be recog- nized in considerable amount seven days after the injection. Similar observations were made with chrysamin. The investigations of the color prepared from the w-ni- traniline and /5-napbthol, /-nitraniline and Schgeffer's salt, /- nitraniliue and naphthionic acid (archil-substitute), showed that the introduction of a nitro-group into an azo-color does not necessarily produce a poisonous body, this being contrary to what the experiments with the nitro-colors proper has led us to anticipate. This harmlessness of the nitro-group in the azo- colors is not, however, due to the presence of the sulphonic acid group, — the detoxicating influence of which was recognized in connection with the nitro-group. For instance, w-nitrazotin, prepared from w-nitraniline and /5-naphthol, contains no sul- 148 THE COAL-TAR COLORS. phonic group and yet is non-poisonous, in spite of the nitro- group present. Further, in spite of the presence of the sulphonic groups, colors may be poisonous, as is shown with orange II, pre- pared from /-amidobenzenesulphonic acid and /3-naphtho], and metanil yellow, prepared from ///-amidobenzenesulphonic acid and diphenylamine. The poisonous qualities of orange II and metanil yellow are not referable with certainty to their consti- tution, since two other colors of known constitution, closely analogous to them have been shown to be non-poisonous. For instance, the poisonous metanil yellow corresponds to the non- poisonous diphenylamine orange. The difference between the two is in the relation between the sulphonic group and the azo-group. In diphenylamine orange, these groups stand to each other in the para-position ; in metanil yellow, in the meta-posi- tion. The correctness of these formulae is shown by the fact that the metanil yellow is obtained by the diazotizing of w-ami- dobenzenesulphonicacid, while diphenylamine orange is obtained by diazotizing /-amidobenzenesulphonic acid. Further,* orange II, which is poisonous, corresponds to another color, orange I, which is not poisonous. These bodies differ only in the position of the hydroxyl in the naphthalene residue. In orange II the hydroxy! has the /5-position ; in orange I, the a-position. This is shown by the methods of preparing the colors, one being made from «- and the other from /J-naphthol. Other azo- colors which contain the /5-naphthol residue, for instance, Soudan I, new coccin, fast red B, xylidine red, and azarin S, are entirely non-poisonous. The urine obtained from the animals fed or treated subcutane- ously with the azo-colors was generally colored and contained the unchanged color only when considerable quantities of the mate- rial had been administered. A portion of the color adminis- tered was found in the faeces, and especially when the color was insoluble. Generally the complex color molecule is split up in the animal organism into uncolored derivatives. When animals to which azo-colors have been administered have excreted a urine of normal color, I have never been able to obtain any coloring materials analogous to the azo-body used. APPENDIX. Formation of Dyestuffs. — The conditions under which an uncolored body, or one not capable of coloring fibres, be- comes converted into a dyestuff are explained by the following theoretical suggestions of O. N. Witt. Witt assumes the presence of certain characteristic groups — chromophorous groups — in all dyestuffs, which, by introduction into colorless bodies, give rise to the basis structure of dyestuffs — chromogenous groups. When these chromogenous groups are joined to salt-forming groups, such as hydroxyl or amidogen, dyestuffs are formed. The following are examples of chromophorous groups : — -NO, characteristic for nitro- colors. — NO " " nitroso-colors. — N^:.: N- — " " azo-colors. R — N 1 C ~J " " rosaniline colors, R — O I I C > il R — CO i-ci CO 1 1 CO " " rosolic acid colors. " " phthalein colors (eosin, etc.). " " anthraquinone colors (alizarin), 149 150 THE COAL-TAR COLORS I R — N N — — I characteristic for indamines. " indophenols. R- 1 -0 1 N 1 R- 1 - s 1 1 N- 1 - R 1 N J " methyl blue, etc. N = N (azine group) characteristic for azines, safranine, etc. — CO — C = I . " " indigo. — NH Azobenzene, CgHj — N = N — CgHg, contains the chromo- phorous group — N = N — , and is a chromogen, but not a dye, because it has no affinity for fibres. By introduction of NH^, or HO, we obtain respectively amidoazobenzene and hydroxyazo- benzene, both of which are dyes. Salt-forming groups, which de- velop the coloring power of bodies, are called ''auxochromous" groups. Representing by R, Rx, Ry, Rz various hydrocarbon radicles, we may express the principal types of azo-compounds as fol- lows : — Monazo-colors : — R- - N = = N — Rx HO R- -N:. x^ p HO - j\ — Ry HSO3 R- - N.- - N — Rx NH, R- -Nzz .N-RxOH HSO, APPENDIX. 151 Primary diazo-colors :• R _N-^N\p R _ N := N / R _ N = N Ry — N zS}*^^ no HO Ry::N=:S^R'eutic Gazette, " The clinical descriptions are clear and full, and the methods of treatment described are those generally recognized as being the most modern and satisfactory." — The London Lancet. Guide to the E^xamination of Urine. Tenth E^dition. For the Use of Physicians and Students. With Colored Plate and Numerous Illustrations Engraved on Wood. Tenth Edition, Revised, Enlarged, and in many parts entirely rewritten. Cloth, ^1.50 '^:^ A French translation of this book has been pub- lished in Paris. " The book is probably more widely and generally known and ap- preciated than any of its similars in subject and scope." — New York Medical Journal. " The book is a reliable one, and should find a place in the library of every practitioner and student of medicine." — Boston Medical and Surgical Journal. Ha-ndbcok of Physica.1 Dia.gno£is. Fourth Edition. Revised and Enlarged. With two Colored Plates and 55 other Illustrations. 298 pages. i2mo. Cloth, ^1.50 " Like everything else emanating from this distinguished author this little book is replete with practical information from beginning to end." — The Chicago Aledical Recorder. " The author approaches his subject from a practical point of view and the little work will prove a good friend to the student."-— The American Journal 0/ the MedicalSciencet. 3 NEV THIRD EDITION— NOV READY MORRIS' Anatomy Rewritten — Revised — Improved WITH MANY NEW ILLUSTRATIONS Out of 102 of the leading medical schools 60 recommend "Morris." It contains many features of special advantage to students. It is modern, up-to-date in every respect. It has been carefully revised, the articles on Osteology and Nervous System having been rewritten. Each copy con- tains the colored illustrations and a Thumb Index. Octavo. With S46 Illustrations, of which 267 are printed in colors. CLOTH, $6.00; LEATHER. $7.00 " The ever-growing popularity of the book with teachers and stu- dents is an index of its value, and it may safely be recommended to all interested." — From The Medical Record, New York. "Of all the text-books of moderate size on human anatomy in the English language, Morris is undoubtedly the most up-to-date and accu- rate." — From The Philadelphia Medical Journal. McMurrich — Embryology THE DEVELOPMENT OF THE HUMAN BODY With 270 Illustrations A Text- Book for Medical Students. By J. Playfair McMurrich, Professor of Anatomy, Medical Department, University of Michigan. 527 pages. Cloth, ;?3.oo NINTH EDITION POTTER'S MATERIA MEDICA, PHARMACY, AND THERAPEUTICS An Exhaustive Handbook Including the Action of Medicines, Special Therapeutics of Disease, Official and Practical Pharmacy, and Minute Direc- tions for Prescription Writing, etc. Including over 650 Prescriptions and Formulae. By Samuel O. L. Potter, M.A., M.D., M.R.C.P. (Lond.), formerly Professor of the Principles and Practice of Medicine, Cooper Medical Col- lege, San Francisco ; Major and Brigade Surgeon, U. S. Vol. Ninth Edition, Revised and Enlarged. 8vo. With Thumb Index in each copy. Cloth, ^5.00 ; Leather, ^6.00 *^*This is the most complete and trustworthy book for the use of students and physicians. Students who pur- chase it will find it to contain a vast deal of information not in the usual text-books arranged in the most practical man- ner for facilitating study and reference. It cannot be sur- passed as a physician's working book. WHITE AND WILCOX. Materia Medica, Pharmacy^ Pharmacologfy^ and Thera- peutics. Fifth Edition* A Handbook for Students. By W. Hale White, m.d., F.R.C.P., etc., Physician to, and Lecturer on Materia Medica and Therapeutics at, Guy's Hospital, etc. Fifth American Edition, Revised by Reynold W. Wilcox, M A. , M. D. , ll.d. , Professor of Clinical Medicine and Thera- peutics at the New York Post-Graduate Medical School and Hospital ; Visiting Physician, St. Mark's Hospital ; Assist- ant Visiting Physician, Bellevue Hospital. i2mo. Cloth, ^3iOo ; Leather, 1^3. 50 SUBJECT INDEX. Gould's Medical Dictionaries, - Pages 12, 13 Morris* Anatomy, New Edition, - - Page 4 Compends for Students, - - - - Page 27 SUBJECT. PAQB Alimentary Canal (see Sur- gery) 24 Anatomy 7 Anesthetics 18, 19 Autopsies (see Pathology) 20 Bacteriology 8 Bandaging (see Surgery) . . 24 Blood, Examination of . . . 8 Brain 8 Chemistry. Physics .... 9 Children, Diseases of 11 Climatology 19 Clinical Charts 25 Compends 27 Consumption (see Lungs) . 16 Cyclopedia of Medicine ... 13 Dentistry 11 Diabetes(seeUrin. Organs) 25 Diagnosis 11 Diagrams (see Anatomy) . 8 Dictionaries, Cyclopedias. 12 Diet and Food 13 Disinfection 16 Dissectors 7 Ear 14 Electricity 14 Embryology 7 Emergencies 24 Eye 14 Fevers 15 Food 13 Formularies 21 Gynecology 15 Hay Fever 25 Heart 15 Histology 15 Hydrotherapy 19 Hygiene 16 Hypnotism 8 Insanity 8 Intestines 23 Latin, Medical (see Phar- macy) 21 Life Insurance 19 Lungs 16 Massage 17 Materia Medica 17 Mechanotherapy 17 Medical Jurisprudence .... 18 SUBJECT. PAoa Mental Therapeutics 8 Microscopy 18 Milk 8,10 Miscellaneous 18 Nervous Diseases 19 Nose 25 Nursing 20 Obstetrics 20 Ophthalmology 14 Organotherapy 18 Osteology (see Anatomy) . 7 Pathology 20 Pharmacy 21 Physical Diagnosis 11 Physical Training 17 Physiology 22 Pneumotherapy 19 Poisons (see Toxicology) . . 18 Practice of Medicine 22 Prescription Books (Phar- macy) 21 Refraction (see Eye) 14 Rest 19 Sanitary Science n 16 Serum-Therapy 17 Skin ♦. . . 23 Spectacles (see Eye) ..... 14 Spine (see Nervous Dis- eases) 19 Stomach 23 Students' Compends ..... 27 Surgery and Surgical Dis- eases 24 Technological Books ..... 9 Temperature Charts 25 Therapeutics 17 Throat 25 Toxicology 18 Tumors (see Surgery) .... 24 U. S. Pharmacopoeia 22 Urinary Organs 25 Urine 25 Venereal Diseases 26 Veterinary Medicine 26 Visiting Lists, Physicians'. (Send lor Special Circu- lar.) Water Analysis 16 Women, Diseases of 15 Self-Examination tor Medical Students. 3500 Questions on Medical Subjects, with References to Standard Works in which the correct replies will be found. Together with Questions from State Examining Boards. 8d Ed. Paper Cover, 10 ot». SUBJECT CATALOGUE OF MEDICAL BOOKS. SPECIAL NOTE. — The prices given in this catalogue are net ; no discount can be allowed retail purchasers under any con- sideration. This rule has been established in order that everyone will be treated alike, a general reduction in former prices having been made to meet previous retail discounts. Upon receipt of the advertised price any book will be forwarded by mail or express, all charges prepaid. ANATOMY. EMBRYOLOGY. MORRIS. Text-Book of Anatomy. Third Revised and Enlarged Edition. 846 Illustrations, 267 of which are printed in colors. Thumb Index in Each Copy. Cloth, $6.00 ; Leather, $7.00 "The ever-growing popularity of the book with teachers and students is an index of its value." — Medical Record. New York. BROOMELL. Anatomy and Histology of the Human Mouth and Teeth. 2d Edition, Enlarged. 337 Illus. Cloth, $4.60 DAVISON. Mammalian Anatomy. With Special Reference to the Cat. 108 Illustrations. Just Ready. $1.50 DEAVER. Surgical Anatomy. A Treatise on Anatomy in its Application to Medicine and Surgery. With 499 very hand- some full-page Illustrations Engraved from Original Drawings made by special Artists from dissections prepared for the pur- pose. Three vols. By Subscription only. Half Morocco or Sheep, $24.00 ; Half Russia, $27.00 GORDINIER. Anatomy of the Central Nervous System. With 271 Illustrations, many of which are original. Cloth, $6.00 HEATH. Practical Anatomy. 9th Edition. 321 Illus. $4.25 HOLDEN. Anatomy. A Manual of Dissections. Revised by A. Hbwson, M.D., Demonstrator of Anatomy, Jefferson Medical College, Philadelphia. 320 handsome Illustrations. 7th Ed. In two compact 12mo volumes. 850 pages. Large New Type. Vol. I. Scalp— Face— Orbit— Neck— Throat— Thorax — Up- per Extremity. $1.60 Vol. II. Abdomen — Perineum — Lower Extremity — Brain — Eve — Ear — Mammary Gland — Scrotum — Testes. $1.50 HOLDEN. Human Osteology. Comprising a Description of the Bones, with Colored Delineations of the Attachments of the Muscles. The General and Microscopical Structure of Bone and its Development. With Lithographic Plates and numer- ous Illustrations. 8th Edition. $6.26 HOLDEN. Landmarks, Medical and Surgical. 4th Ed. .75 HUGHES AND KEITH. Dissections. With 527 Colored Plates and other Illustrations. In three parts. I, Upper and Lower Extremity. $3.00 II, Abdomen— Thorax'. $3.00 III, Head — Neck — Central Nervoxis System. $3.00 LAZARUS-BARLOW. Pathological Anatomy. 21 Plates and 171 other Illustrations. Just Ready. $6.60 McMURRICH. Embryology. The Development of the Human Body. 276 lUustrations. $3.00 8 SUBJECT CATALOGUK MARSHALL. Physiological Diagrams. Eleven Life-Size Colored DiaKrama (each seven feet by three feet seven inches). Designed for Demonstration before the Class. In Sheets, Unmounted, $40.00; Backed with Muslin and Moxinted on Rollers, $60.00; Ditto, Spring Rollers, in hand- some Walnut Wall Map Case, $100.00; Single Plates— Sheets, $5.00; Mounted, $7.60. Explanatory Key, .50. Purchaser must pay freight charges. MINOT. Laboratory Text-Book of Embryology. 218 Illustra- tions. Just Ready. $4.50 POTTBR. Compend of Anatomy, Including Visceral Anatomy. 7th Edition, Revised and Enlarged. 16 Plates and 138 other Illustrations. Just Beady. .80; Interleaved, $1.00 WILSON. Anatomy. 11th Edition. 429 Illus., 26 Plates. $5.00 YUTZY. Guide to the Dissection of the Human Body. Based on Morris' Anatomy. Paper Cover, .25 BACTERIOLOGY- CONN. AgricTiltural Bacteriology, Including the Study of Bacteria as relating to Agriculture, Soil, Dairy and Food Products, Sewage, Domestic Animals, etc. Illustrated. $2.50 CONN. Bacteria in Milk and Its Products. Designed for Students of Dairying, Boards of Health, Bacteriologists, etc. Illustrated. $1.25 EMERY. Bacteriological Diagnosis. 2 Colored Plates and 32 other Illustrations. $1.50 HEWLETT. Manual of Bacteriology. 75 Illustrations. Second Edition, Revised and Enlarged. $4.00 SMITH. Laboratory Exercises in Bacteriology. A Handbook for Students. Illustrated. $1.50 WILLIAMS. Bacteriology. A Manual for Students. 99 Illus- trations. 3d Edition, Revised. Just Beady. $1.50 BLOOD, Examination of. DA COSTA. Clinical Hematology. A Practical Guide to the Examination of the Blood, with Reference to Diagnosis. Six Colored Plates and 48 other lUus. Cloth. $5.00 ; Sheep, $6.00 BRAIN AND INSANITY (see also Nervous Diseases.) BLACKBURN. A Manual of Autopsies. Designed for the Use of Hospitals for the Insane and other Public Institutions. Ten full-page Plates and other Illustrations. $1.25 CHASE. General Paresis. Illustrated. $1.75 DERCUM. Mental Therapeutics, Rest, Suggestion. See Cohen, Physiologic Therapeutics, page 17. 60RDINIER. The Gross and Minute Anatomy of the Central Nervous System. With full-page and other lUus. $6.00 IRELAND. The Mental Affections of Children. 2d Ed. $4.00 LEWIS (BEVAN). Mental Diseases. A Text-Book having Special Reference to the Pathological Aspects of Insanity. 26 Lithographic Plates and other Illustrations. 2d Ed. $7.00 MEDICAL BOOKS. 9 MAIVN. Manual of Psychological Medicine. S3.00 PERSHING. Diagnosis of Rervout and Mental Disease. Illus- trated. $1-25 REGIS. Mental Medicine. Authorised Translation by H. M. Bankistsr, u.d. $2.00 STEARNS. Mental Diseases. With a Digest of Laws Relating to Care of Insane. Illustrated. Cloth, $2.75; Sheep, $3.25 TUEIE. Dictionary of Psychological Medicine. Giving the Definition, Etymology, and Symptoms of the Terms used in Medical Psychology, with the Symptoms, Pathology, and Treatment of the Recognized Forms of Mental Disorders. Two volumes. $10.00 WOOD, H. C. Brain and Overwork. .40 CHEMISTRY AND TECHNOLOGY. Special Catalogue of Chemical Book* $ent free upon application. ALLEN. Commercial Organic Analysis. A Treatise on the Modes of Assaying the Various Organic Chemicals and Prod- ucts Employed in the Arts, Manufactures, Medicine, etc., with Concise Methods for the Detection of Impurities, Adul- terations, etc. 8vo. Vol. I. Alcohols, Neutral Alcoholic Derivatives, etc.. Ethers, Vegetable Acids, Starch, Sugars, etc. 3d Edition. $4.50 Vol. II, Part I. Fixed Oils and Fats, Glycerol, Explosives, etc. 3d Edition. $3.50 Vol. II, Part 11. Hydrocarbons, Mineral Oils, Lubricants, Benzenes, Naphthalenes and Derivatives, Creosote, Phenols, etc. 3d Edition. $3.60 Vol. II, Part III. Terpenes, Essential Oils, Resins, Camphors, etc. 3d Edition. In Press. Vol. Ill, Part I. Tannins, Dyes, and Coloring Matters. 3d Edition, Enlarged and Rewritten. Illustrated. $4.50 Vol. Ill, Part II. The Amines, Hydrazines and Derivatives, Pyridine Bases. The Antipyretics, etc. Vegetable Alka- loids, Tea, Coffee, Cocoa, etc. 8vo. 2d Edition. $4.50 Vol. Ill, Part III. Vegetable Alkaloids, Non-Basic Vegetable Bitter Principles. Animal Bases, Animal Acids, Cyanogen Compounds, etc. 2d Edition, 8vo. $4.50 Vol. IV. The Proteids and Albuminous Principles. 2d Edition. ^ $4.50 BAILEY AND CADY. Qualitative Chemical Analysis. $1.25 BARTLEY. Medical and Pharmaceutical Chemistry. A Text- Book for Medical, Dental, and Pharmaceutical Students. With Illustrations, Glossary, and Complete Index. 6th Ed. $3.00 BARTLEY. Clinical Chemistry. The Examination of Feces, Saliva, Gastric Juice, Milk, and Urine. $1.00 BLOXAM. Chemistry, Inorganic and Organic. With Experi- ments. 9th Ed., Revised. 284 Engravings. $6.00 BUNGE. Physiologic and Pathologic Chemistry. From the Fourth German Enlarged Edition. $3.00 CALDWELL. Elements of Qualitative and Quantitative Chem- ical Analysis. 3d Edition, Revised. $1.00 10 SUBJECT CATALOGUE.' CAMERON. Soap and Candles. 64 Illustrations. $2.00 CLOWES AND COLEMAN. Quantitative Analysis. 6th Edi- tion. 125 Illustrations. $3.50 COBLENTZ. Volumetric Analysis. Illustrated. $1.25 CONGDON. Laboratory Instructions in Chemistry. With Numerous Tables and 56 Illustrations. $1.00 GARDNER. The Brewer, Distiller, and Wine Manufacturer. lUustrated. $1.50 GRAY. Physics. Volume I. Dynamics and Properties of Matter. 350 Illustrations. $4.50 GROVES AND THORP. Chemical Technology. The Applica- tion of Chemistry to the Arts and Manufactures. Vol. I. Fuel and its Applications. 607 Illustrations and 4 Plates. Cloth, $5.00; i Mor., $6.50 Vol. II. Lighting. Illustrated. Cloth, $4.00; i Mor., $5.50 Vol. III. Gas Lighting. Cloth, $3.50; i Mor., $4.50 Vol. IV. Electric Lighting. Photometry. Cloth, $3.50; i Mor., $4.50 HEUSLER. The Chemistry of the Terpenes. $4.00 HOLLAND. The Urine, the Gastric Contents, the Common Poisons, and the Milk. Memoranda, Chemical and Micro- scopical, for Laboratory Use. 6th Ed. Illustrated. $1.00 LEFFMANN. Compend of Medical Chemistry, Inorganic and Organic. 4th Edition, Revised. .80; Interleaved, $1.00 LEFFMANN. Analysis of Milk and Milk Products. 2d Edition, Enlarged. Illustrated. $1.26 LEFFMANN. Water Analysis. For Sanitary and Technio Pur- poses. Illustrated. 5th Edition. $1.25 LEFFMANN. Structural Formulae. Including 180 Structural and Stereo-Chemical Formulae. 12mo. Interleaved. $^.00 LEFFMANN AND BEAM. Select Methods in Food Analysis. Illustrated. $2.50 MUTER. Practical and Analytical Chemistry. 3d American from the Ninth English Edition. Revised to meet the re- quirements of American Students. 56 Illustrations. $1.25 OETTEL. Exercises in Electro-Chemistry. Illustrated. .75 OETTEL. Electro-Chemical Experiments. Illustrated. .75 RICHTER. Inorganic Chemistry. 6th American from 10th German Edition. Authorized translation by Edgak F. Smith, M.A , PH.D. 89 Illustrations and a Colored Plate. $1.76 RICHTER. Organic Chemistry. 3d American Edition, trans- lated from the 8th German by Edgar F. Smith. Illus. 2 vols. Vol. I. Aliphatic Series. 625 pages. $3.00 Vol. II. Carbocyclic Series. 671 pages. $3.00 ROCKWOOD. Chemical Analysis for Students of Medicine, Dentistry, and Pharmacy. Illustrated. $1.50 SMITH. Electro-Chemical Analysis. 3d Ed. 39 Illus. $1.50 SMITH AND KELLER. Experiments. Arranged for Students in General Chemistry. 4th Edition. Illustrated. .60 SUTTON. Volumetric Analysis. A Systematic Handbook for the Quantitative Estimation of Chemical Substances by Measure, Applied to Liquids, Solids, and Gases. 8th Edition, Revised. 112 Illustrations. $5.00 SYMONDS. Manual of Chemistry. 2d Edition. $2.00 TRAUBE. Physico-chemical Methods. 97 lUustrationt. $1.60 MEDICAL BOOKS. 11 THRESH. Water and Water Supplies. 3d Edition. $2.00 ULZER AND FRAENKEL. Chemical Technical Analysis. Translated by Fleck. Illustrated. $1.25 WOODY. Essentials of Chemistry and Urinalysis. 4th Edition. Illustrated. $1.50 *♦* Special Catalogue of Books on Chemistry free upon application. CHILDREN. HATFIELD. Compend of Diseases of Children. With a Colored Plate. 3d Ed. Just Ready. .80 ; Interleaved, $1.00 IRELAND. The Mental Affections of Children. Idiocy, Im- becility, Insanity, etc. 2d Edition. $4.00 POWER. Surgical Diseases of Children and their Treatment by Modern Methods. Illustrated. $2.50 STARR. The Digestive Organs in Childhood. The Diseases of the Digestive Organs in Infancy and Childhood. 3d Edition, Rewritten and Enlarged. Illustrated. $3.00 STARR. Hygiene of the Nursery. Including the General Regi- men and Feeding of Infants and Children, and the Domestic Management of the Ordinary Emergencies of Early Life, Massage, etc. 6th Edition. 25 Illustrations. $1.00 SMITH. Wasting Diseases of Children. 6th Edition. $2.00 TAYLOR AND WELLS. The Diseases of Children. 2d Edition, Revised and Enlarged. Illustrated. 8vo. $4.50 " It is well worthy the careful study of both student and prac- titioner, and can not fail to prove of great value to both. We do not hesitate to recommend it." — Boston Medical and Surgical Journal. DIAGNOSIS. BROWN. Medical Diagnosis. A Manual of Clinical Methods. 4th Edition. 112 Illustrations. Cloth, $2.25 DA COSTA. Clinical Hematology. A Practical Guide to Exam- ination of Blood, with Reference to Diagnosis. 6 Colored Plates, 48 other Illustrations. Cloth, $5.00 ; Sheep, $6.00 DOUGLAS. Surgical Diseases of Abdomen, with Reference to Diagnosis. 20 Full-Page Plates. Just Ready. Cloth, $7.00 ; Sheep, $8.00 EMERY. Bacteriological Diagnosis. 2 Colored Plates and 32 other Illustrations. $1.50 MEMMINGER. Diagnosis by the Urine. 2d Ed. 24 lUus. $1.00 PERSHING. Diagnosis of Nervous and Mental Diseases. Illustrated. $1.25 STEELL. Physical Signs of Pulmonary Disease. $1.25 TYSON. Handbook of Physical Diagnosis. For Students and Physicians. By the Professor of Clinical Medicine in the Uni- versity of Pennsylvania. Illus. 4th Ed., Improved and En- larged. With 2 Colored and 55 other Illustrations. $1.50 DENTISTRY. Special Catalogue of Dental Book* tent free upon application. BARRETT. Dental Surgery for General Practitioners and Students of Medicine and Dentistry. Extraction of Teeth, eta. 3d Edition. Illustrated. $1.00 12 SUBJECT CATALOGUE. BROOMELL. Anatomy and Histology of the Human Mouth and Teeth. Second Edition, Revised and Enlarged. 337 handsome Illustrations. Cloth, $4.50; Leather, $5.50 FILLEBROWN. Operative Dentistry. Illustrated. $2.26 GORGAS. Dental Medicine. A Manual of Materia Medica and Therapeutics. 7th Edition. Cloth, $4.00 ; Sheep,$5.00 GORGAS. Questions and Answers for the Dental Student. Embracing all the subjects in the Curriculum of the Dental Student. Octavo. $6.00 HARRIS. Principles and Practice of Dentistry. Including Anatomy, Physiology, Pathology, Therapeutics, Dental Sur- gery, and Mechanism. 13th Edition. Revised by F. J. S. GoRGAS, M.D., D.D.s. 1250 Illus. Cloth. $6.00 ; Leather, $7.00 HARRIS. Dictionary of Dentistry. Including Definitions of Such Words and Phrases of the Collateral Sciences as Pertain to the Art and Practice of Dentistry. 6th Edition, Revised and Enlarged by Ferdinand J. S. Goroas, m.d., ^.s.b. Cloth, $5.00; Leather. $6.00 RICHARDSON. Mechanical Dentistry. 7th Edition. Thor- oughly Revised and Enlarged by Dk. Gho. W. Warrbn. 691 Illustrations. Cloth, $5.00; Leather, $6.00 SMITH. Dental Metallurgy. 2d Edition. Illustrated. $2.00 TAFT. Index of Dental Periodical Literature. $2.00 TOMES. Dental Anatomy. 263 Illustrations. 6th Ed. $4.00 TOMES. Dental Surgery. 4th Edition. 289 Illu». $4.00 WARREN. Compend of Dental Pathology and Dental Medicine. With a Chapter on Emergencies. th Edition. Illustrated. .80; Interleaved, $1.00 WARREN. Dental Prosthesis and Metallurgy. 129 Illus. $1.25 WHITE. The Mouth and Teeth. Illustrated. .40 DICTIONARIES. CYCLOPEDIAS. GOULD. The Illustrated Dictionary of Medicine, Biology, and Allied Sciences. Being an Exhaustive Lexicon of Medicine and those Sciences Collateral to it: Biology (Zoology and Botany), Chemistry, Dentistry, Pharmacology, Microscopy, etc., with many useful Tables and numerous fine Illustrations. 1633 pages. Fifth Edition. ^ Sheep or Half Morocco. $10.00: with Thumb Index, $11.00 Half Russia, Thumb Index, $12.00 GOULD. The Medical Student's Dictionary, nth Edition. Il- lustrated. Including those Words and Phrases generally used in Medicine, with their Proper Pronunciation and Definition, Based on Recent Medical Literature. With Table of Epo- nymio Terms and Tests and Tables of the Bacilli, Micrococci, Mineral Springs, etc., of the Arteries, Muscles, Nerves, Ganglia, Plexuses, etc. Eleventh Edition. Enlarged and illustrated with a large number of Engravings. 840 pages. Half Morocco, $2.50 ; with Thumb Index, $3.00 FlexibleXeather, Burnished Edges, Thumb Index, 3.50 MEDICAL BOOKS. 13 GOULD. The Pocket Pronoxincing Medical Lexicon. 4th Edi- tion. (30,000 Medical Words Pronounced and Defined.) Con- tainine all the Words, their Definition and Pronunciation, that the Medical, Dental, or Pharmaceutical Student Gener- ally Comes in Contact with; also Elaborate Tables of Epo- nynr\io Terms, Art«rie9, Muscles, Nerves, Bacilli, etc., etc., a Dose List in both Englinh and Metric Systems, etc.. Arranged in a Most Convenient Form for Reference and Memorising. Fourth Edition, Reviaed and Enlarged. 838 pages. Full Limp Leather, Gilt Edges, $1.00; Thumb Index, $1.25 145,000 Copies of Gould's Dictionaries have been sold. GOULD AITD PYLE. Cyclopedia of Practical Medicine and Surgery. Seventy-two Special Contributors. Illustrated. One Volume. A Concise Reference Handbook of Medicine, Sur- gery, Obstetrics, Materia Medica, Therapeutics, and the Vari- ous Specialties, with Particular Reference to Diagnosis and Treatment. CompUed under the Editorial Supervision of GaoRQB M. Gould, m.©.. Author of "An Illustrated Dictionary of Medicine," etc.; and WjLltkr L. Ptlb, m.d., Assistant Surgeon Wills Eye Hospital; formerly Editor "International Me<£cal Magasine," etc., and Seventy-two Special Contribu- tors. With many Illustrations. Large Square 8vo, to corre- spond with Gould's "Illustrated Dictionary." Full Sheep or Half Mor., $10.00; with Thumb Index, $11.00 Half Russia, Thumb Index, $12.00 net. GOULD AKD PYLE. Pocket Cyclopedia of Medicine and Sur- gery. Based upon above book and uniform in size with "Gould's Pocket Dictionary." FuU Limp Leather, GUt Edges, $1.00 With Thumb Index, $1.25 HARRIS. Dictionary of Dentistry. Including Definitions of Such Words and Phrases of the Collateral Sciences as Pertain to the Art and Practice of Dentistry. 6th Edition, Revised and Enlarged by Fkbdinand J. S. Gorgas, m.d., d.d.s. Cloth, $5.00: Leather, $6.00 LONGLEY. Pocket Medical Dictionary. Cloth, .75 TREVES AITD LANG. German-English Medical Dictionary. Half Calf, $3.25 DIET AND FOOD. ALLEN. Proteids and Albuminous Principles. An analytical Study of Food Products. 2d Edition. $4.50 BURNETT. Foods and Dietaries. A Manual of Clinical Diet- etics, with Diet Lists for Various Diseases, etc. 2d Ed. $1.50 DAVIS. Dietotherapy. Food in Health and Disease. With Tables of Dietaries, Relative Value of Foods, etc. See Cohen, Phyaiologic Therapeutic*, page 17. GREENISH. Microscopical Examination of Foods and Drugs. Illustrated. Just Ready. $3.50 HAIG. Diet and Food. Considered in Relation to Strength and Power of Endurance. 4th Edition. $1.00 LEFFMANN. Select Methods in Food Analysis. Ulua. $2.50 14 SUBJECT CATALOGUE. EAR (see also Throat and Nose). BURNETT. Hearing and How to Keep It. Illustrated. .40 HOVELL. Diseases of the Ear and Naso-Pharynx. Including Anatomy and Physiology of the Organ, together with the Treatment of the Affections of the Nose and Pharynx which Conduce to Aural Disease. 128 Illustrations. 2d Ed. $5.50 PRITCHARD. Diseases of the Ear. 4th Edition, Enlarged. Many Illustrations and For/nul£e. In Press. ELECTRICITY. BIGELOW. Plain Talks on Medical Electricity and Batteries. With a Therapeutic Index and a Glossary. 43 Illustrations. 2d Edition. $1.00 HEDLEY. Therapeutic Electricity and Practical Muscle Testing. 99 Illustrations. $2.50 JACOBY. Electrotherapy. 2 volumes. Illustrated. See Cohen, Physiologic Therapeutics, page 17. JONES. Medical Electricity. 3d Edition. 117 lUus. $3.00 EYE. A Special Circular of Books on the Eye sent free upon application. DARIER. Ocular Therapeutics. Just Beady. $3.00 DONDERS. The Nature and Consequences of Anomalies of Refraction. With Portrait and lUus. Half Morocco, $1.25 FICK. Diseases of the Eye and Ophthalmoscopy. Translated by A. B. Halb, M.D. 157 Illus. Cloth, $4.50; Sheep, $5.50 GOULD AND PYLE. Compend of Diseases of the Eye and Re- fraction. Including Treatment and Operations, and a Section on Local Therapeutics. With Formulae, Usefiil Tables, %. Glossary, and 111 Illus., several of which are in colors. 2d Edition, Revised. Cloth, .80; Interleaved, $1.00 GREEFF. The Microscopic Examination of the Eye. Illus- trated. $1.25 HARLAN. Eyesight, and How to Care for It. Illus. .40 HARTRIDGE. On the Ophthahnoscope. 4th Edition. With 4 Colored Plates and 68 Wood-cuts. $1.60 HARTRIDGE. Refraction. 104 Illustrations and Test Types. 12th Edition, Enlarged. $1.50 HANSELL AND SWEET. Treatise on Diseases of the Eye. With 253 Illustrations. $4.00 HANSELL AND REBER. Muscular Anomalies of the Eye. Illustrated. $1.50 HANSELL AND BELL. Clinical Ophthalmology. Colored Plate of Normal Fundus and 120 Illustrations. $1.50 HENDERSON. Notes on the Eye. 3d Ed. Just Ready. $1.50 JENNINGS. Manual of Ophthalmoscopy. 95 Illustrations and 1 Colored Plate. $1.50 MORTON. Refraction of the Eye. Its Diagnosis and the Cor- rection of its Errors. 6th Edition. $1.00 OHLEMANN. Ocular Therapeutics. Authorized Translation, and Edited by Dr. Charles A. Olivbr. $1.76 PARSONS. Elementary Ophthalmic Optics. With Diagram- matio Illustrations. $2.00 MEDICAL BOOKS. 15 PHILLIPS. Spectacles and Eyeglasses. Their Prescription and Adjustment. 3d Edition. 52 Illustrations. $1.00 SWANZY. Diseases of the Eye and Their Treatment. 8th Edition, Revised and Enlarged. 168 Illustrations, 1 Plain Plate and a ZephjT Test Card. Just Ready. $2.50 THORINGTON. Retinoscopy. 4th Edition, Carefully Revised. Illustrated. $1.00 THORINGTON. Refraction and How to Refract. 200 lUustra- tions, 13 of which are colored. 2d Edition. $1.50 WALKER. Student's Aid in Ophthabnology. Colored Plate and 40 other Illustrations and a Glossary. $1.50 WORTH. Squint : Its Causes, Pathology, Treatment. $2.00 WRIGHT. Ophthalmology. 2d Edition, Revised and Enlarged. 117 Illustrations and a Glossary. $3.00 FEVERS. GOODALL AND WASHBOURN. Fevers and Their Treatment. Illustrated. $3.00 WILCOX. Fever Nursing. In Press. GYNECOLOGY. BISHOP. Uterine Fibromyomata. Their Pathology, Diag- nosis, and Treatment. Illustrated. Cloth, $3.50 BYFORD (H. T.). Manual of Gynecology. 3d Edition, Revised and Enlarged. 363 Illustrations. S3.00; Sheep, $3.50 DtJHRSSEN. A Manual of Gynecological Practice. 105 Illus- trations. $1.50 FTJLLERTON. Surgical Nursing. 3d Edition, Revised and Enlarged. 69 Illustrations. $1.00 GALABIN. Diseases of Women. Sixth Edition. By Alfred Lewis Galabin, m.a., m.d., f.r.c.p. 6th Edition, Revised and Enlarged. 284 Illustrations. Octavo. Cloth, $5.00 LEWERS. Diseases of Women. 146 Illus. 5th Ed. $2.50 LEWERS. Cancer of the Uterus. Jitst Ready. $3.00 MONTGOMERY. Practical Gynecology. A Complete Sys- tematic Text-Book. 2d Edition, Revised and Enlarged. With 539 Illus. Just Ready. Cloth, $5.00; Leather, $6.00 ROBERTS. Gynecological Pathology. With 127 Full-page Plates containing 151 Figures. $6.00 WELLS. Compend of Gynecology. Illustrated. 3d Edition, Revised and Enlarged. Just Ready. .80; Interleaved, $1.00 HEART. THORNE. The Schott Methods of the Treatment of Chronic Heart Disease. Fourth Edition. Illustrated. $2.00 HISTOLOGY. GUSHING. Compend of Histology. By H. H. Cushino, m.d., Demonstrator of Histology, Jefferson Medical College, Phila- delphia. Illus. Nearly Ready. .80; Interleaved, $1.00 LAZARUS-BARLOW. Pathological ' Anatomy and Histology. Uluatrated. Just Ready. $6.50 1« SUBJECT CATALOGUE. STIRLING. Outlines of Practical Histology. 368 Illxistrationg. 2d Edition, Revised and Enlarged. With new Illua. $2.00 STOHR. Histology and Microscopical Anatomy. Edited by A. ScHAPBR, M.D., University of Breslau, formerly Demon- strator of Histology, Harvard Medical School. Fifth Amer- ican from 10th German Edition, Revised and Enlarged. 353 nivistrations. $3.00 HYGIENE. Special Catalogue of Books on Hygiene sent free upon application. CAIfFIELD. Hygiene of the Sick-Room. A Book for Nurses and Others. Being a Brief Consideration of Asepsis, Anti- sepsis, Disinfection, Bacteriology, Immunity, Heating, Venti- lation, etc. $1.25 CONN. Agricultural Bacteriology. Illxistrated. $2.50 CONN. Bacteriology of Milk and Milk Products- Hlus. $1.26 COPLIN. Practical Hygiene. A Complete American Text- Book. 138 Illustrations. New Edition. Preparing. HARTSHORNE. Our Homes. Illustrated. .40 KENWOOD. PubUc Health Laboratory Work. 116 Illustra- tions and 3 Plates. $2.00 LEFFMANN. Select Methods in Food Analysis. 53 Illustra- tions and 4 Plates. $2.50 LEFFMANN. Examination of Water for Sanitary and Technical Purposes. 4th Edition. Illustrated. $1.25 LEFFMANN. Analysis of Milk and Milk Products. Illustrated. Second Edition. $1.25 LINCOLN. School and Industrial Hygiene. .40 McFARLAND. Prophylaxis and Personal Hygiene. CSare of the Sick. See Cohen, Physiologic TherapeiUics, page 17. KOTTER. The Theory and Practice of Hygiene. 15 Plates and 138 other Illustrations. 8vo. 2d Edition. $7.00 PARKAS AND KENWOOD. Hygiene and PubUc Health. 2d Edition, Enlarged. Illustrated. $3.00 ROSENAU. Disinfection and Disinfectants. Hlus. $2.00 STARR. The Hygiene of the Nursery. Including the General Regimen and Feeding of Infants and Children, and the Domes- tic Management of the Ordinary Emergencies of Early Life, Massage, etc. 6th Edition. 25 Illustrations. $1.00 STEVENSON AND MURPHY. A Treatise on Hygiene. By Various Authors. In three octavo volumes. Illustrated. Vol. I, $6.00; Vol. II, $6.00; Vol. Ill, $5.00 THRESH. Water and Water Supplies. 3d Edition. $2.00 WILSON. Handbook of Hygiene and Sanitary Science. With Illustrations. 8th Edition. $3.00 WEYL. Sanitary Relations of the Coal-Tar Colors. Authorised Translation by Hbnbt Lsffuann, ii.J>., ph.d. $1.25 LUNGS AND PLEURA. KNOPF. Pulmonary Tuberculosis. Its Modem Prophylaxis and Treatment in Special Institutions and at Home. lUus. $3.00 STEELL. Physical Signs of Pulmonary Disease. Illua. $1.25 MEDICAL BOOKS. 17 MASSAGE. PHYSICAL EXERCISE. OSTROM. Massage and the Orieinal Swedish Movements. Their Application to Various Diseases of the Body. A Manual for Students, Nurses, and Physicians. Fifth Edition, En- larged. 115 Illustrations, many of which are original. $1.00 MITCHELL AND GULICK. Mechanotherapy. Exercise, Ortho- pedics, Massage, Ocular Corrections, etc. Illustrated. Set Cohen, Phytiologie Therapeutics, below. TREVES. Physical Education. Its Value, Methods, etc. .76 MATERIA MEDICA AND THERAPEUTICS. BRACKEN. Outlines of Materia Medica and Pharmacology. $2.75 COBLENTZ. The Newer Remedies. Including their Synonyms, Sources, Methods of Preparation, Tests, Solubilities, Doses, etc. 3(1 Edition, Enlarged and Revised. $1.00 COHEN. Physiologic Therapeutics. Methods other than Drug- Giving useful in the Prevention of Disease and in the Treat- ment of the Sick. Mechanotherapy, Mental Therapeutics, Suggestion, Electrotherapy, Climatology, Hydrotherapy, Pneumatotherapy, Prophylaxis, Dietetics, Organotherapy, Phototherapy, Mineral Waters, Baths, etc. 11 volumes, 8vo. Illustrated. (Subscription.) Cloth, $27.50; ^ Mor., $38.50 Special Descriptive Circular toill be tent upon application. GORGAS. Dental Medicine. A Manual of Materia Medica and Therapeutics. 7th Edition, Revised. $4.00 GROFF. Materia Medica for Nurses, with Questions for Self- Examination. 2d Edition, Revised and Improved. $1.25 HELLER. Essentials of Materia Medicat Pharmacy, and Pre- scription Writing. $1.50 HEWLETT. Serum-Therapy. $1.75 MAYS. Theine in the Treatment of Neuralgia, i bound. .60 POTTER. Handbook of Materia Medica, Pharmacy, and Thera- peutics, including the Action of Medicines, Special Therapeu- tics, Pharmacology, etc., including over 600 Prescriptions and Formulae. 9th Edition, Revised and Enlarged. With Thumb Index in each copy. Just Ready. Cloth, $5.00 ; Sheep, $6.00 ' "In conclusion we may add that Dr. Potter's Therapeutics covers a wider field than many books which bear this title. He discusses a good many drugs which are rarely employed, and therefore the book is as useful to one who wishes to look for un- usual information as it is to him who wishes a handbook for ready reference in the treatment of disease as he meets it from day to day." — Therapeutic Gazette. POTTER. Compend of Materia Medica, Therapeutics, and Pre- scription Writing, with Special Reference to the Physiological Action of Drugs. 6th Edition. .80; Interleaved, $1.00 MURRAY. Rough Notes on Remedies. 4th Edition. $1.25 SAYRE. Organic Materia Medica and Pharmacognosy. An Introduction to the Study of the Vegetable Kingdom and the Vegetable and Animal Drugs. Comprising the Botanical and Physical Characteristics, Source, Constituents, and Pharma- copeial Preparations, Insects Injurious to Drugs, and Pharma- cal Botany. With sections on Histology and Microtechnique, by W. C. St«tbn8. 374 Illustrations, many of which are original. 2d Edition. Cloth, $4.60 18 SUBJECT CATALOGUE. TAVERA. Medicinal Plants of the Philippines. S2.00 WHITE AND WILCOX. Materia Medica, Pharmacy, Pharma- cology, and Therapeutics. 5th American Edition, Revised by Reynold W. Wilcox, m.a., m.d., ll.d., Professor of Clinical Medicine and Therapeutics at the New York Post-Graduate Medical School. Cloth, $3.00 ; Leather, $3.50 MEDICAL JURISPRUDENCE AND TOXICOLOGY. REESE. Medical Jiirisprudence and Toxicology. A Text-Book for Medical and Legal Practitioners and Students. 6th Edition. Revised by Henry Leffmann. m.d. Cloth, $3.00 ; Leather, $3.50 "To the student of medical jurisprudence and toxicology it is invaluable, as it is concise, clear, and thorough in every respect." — The American Journal of the Medical Sciences. MANN. Forensic Medicine and Toxicology. Illua. S6.50 TANNER. Memoranda of Poisons. Their Antidotes and Tests. 9th Edition, by Dr. Henry Leffmann. Just Ready. .75 MICROSCOPY. CARPENTER. The Microscope and Its Revelations. 8th Edition, Revised and Enlarged. 817 Illustrations and 23 Plates. Cloth, $8.00; Half Morocco, $9.00 GREENISH. Microscopical Examination of Foods and Drugs. Illvistrated. Just Ready. $3.50 LEE. The Microtomist's - Vade Mecum. A Handbijok of Methods of Microscopical Anatomy. 887 Articles. 5th Edition, Enlarged. $4.00 OERTEL. Medical Microscopy. A Guide to Diagnosis, Ele- mentary Laboratory Methods and Microscopic Technic. 131 Illustrations. $2.00 REEVES. Medical Microscopy, including Chapters on Bacteri- ology, Neoplasms, Urinary Examination, etc. Numerous Illustrations, some of which are printed in colors. $2.50 WETHERED. Medical Microscopy. A Guide to the Use of the Microscope in Practical Medicine. 100 Illustrations. $2.00 MISCELLANEOUS. BERRY. Diseases of Thyroid Gland. Illustrated. $4.00 BUXTON. Anesthetics. Illustrated. 3d Edition. $1.50 COHEN. Organotherapy. See Cohen, Physiologic Therapeutics, page 17. FRENKEL. Tabetic Ataxia. Illustrated. $3.00 GOULD. Borderland Studies. Miscellaneous Addresses and Ewaye. 12mo. $2.00 GOULD. Biographic Clinics. Volume I. The Origin of the Ill-Health of DeQuincy, Carlyle, Darwin, Huxley, and Browning. $1.00 MEDICAL BOOKS. 19 GOULD Biographic Clinics. Volume II. The Origin of the Ill-Health of Wagner, Parkman, Mrs. Carlisle, Spencer, Whittier, Ossoli, George Eliot, and Nietsche. Nearly Ready. GREENE. Medical Examination for Life Insurance. IUub. With colored and other Engravings. 2d Edition. In Press. ELAIG. Causation of Disease by Uric Acid. The Pathology of High Arterial Tension, Headache, Epilepsy, Gout, Rheuma- tism, Diabetes, Bright's Disease, etc. 6th Edition. $3.50 HENRY. A Practical Treatise on Anemia. Half Cloth, .50 NEW SYDENHAM SOCIETY'S PUBLICATIONS. Circulars upon application. Per Annum, $8.00 OSGOOD. The Winter and Its Dangers. .40 PACKARD. Sea Air and Sea Bathing. .40 RICHARDSON. Long Life and How to Reach It. .40 SCHEUBE. Diseases of Warm Countries. Illustrated. Just Ready. $8.00 TISSIER. Pneumotherapy, Aerotherapy, Inhalation Methods. See Cohen, Physiologic Therapeutics, page 17. TURNBULL. Artificial Anesthesia. 4th Ed. Illus. $2.50 WARDEN. The Paris Medical SchooL Paper, 75 WEBER AND HINSDALE. CUmatology and Health Resorts. Including Mineral Springs. 2 vols. Illustrated with Colored Maps. See Cohen, Physiologic Therapeutics, page 17. WILSON. The Simimer and Its Diseases. .40 WINTERNITZ. Hydrotherapy, Thermotherapy, Phototherapy, Mineral Waters, Baths, etc. Illustrated. See Cohen, Physio- logic Therapeutics, page 17. NERVOUS DISEASES. DERCUM. Rest, Suggestion, Mental Therapeutics. See Cohen, Physiologic Therapeutics, page 17. GORDINIER. The Gross and Minute Anatomy of the Central Nervous System. With 271 original colored and other Illus- trations. Cloth, $6.00; Sheep, $7.00 GOWERS. Syphilis and the Nervous System. $1.00 GOWERS. Manual of Diseases of the Nervous System. A Complete Text-Book. Revised, Enlarged, and in many parts Rewritten. With many new Illustrations. Two volumes. Vol. I. Diseases of the Nerves and Spinal Cord. 3d Edition, Enlarged. Cloth, $4.00; Sheep, $5.00 Vol. II. Diseases of the Brain and Cranial Nerves; General and Functional Disease. 2d Ed. Cloth, $4.00 ; Sheep, $5.00 GOWERS. Epilepsy and Other Chronic Convulsive Diseases. 2d Edition. $3.00 GOWERS. Clinical Lectures. Illustrated. Second Series." ^_ iTt PT€SS HORSLEY. The Brain and Spinal Cord, the Structure and Functions of. Numerous Illustrations. $2.50 ORMEROD. Diseases of the Nervous System. 66 Wood En- gravmgs. $1.00 PERSHING. Diagnosis of Nervous and Mental Diseases. Illus- trated. J1.25 PRESTON. Hysteria and Certain AUied Conditions, Their Nature and Treatment. Illustrated. $2.00 WOOD. Brain Work and Overwork. .40 20 SUBJECT CATALOGUE. NURSING (see also Massage). Special Cataloffue of Bookt for Nurse* tent free upon application. CASTIELD. Hygiene of the Sick-Room. A Book for Nurses and Others. Being a Brief Consideration of Asepsis, Anti- sepsis, Disinfection, Bacteriology, Immunity, Heating and Ventilation, and Kindred Subjects for the Use of Nurses and Other Intelligent Women. S1.25 CUFF. Lectiu-es to Nurses on Medicine. 4th Edition. $1.25 DAVIS. Bandaging. Its Principles and Practice. 163 Original Illustrations. S1.50 DOMVILLE. Manual for Nurses and Others Engaged in At- tending the Sick. 9th Edition. With Recipes for Sick-room Cookery, etc. In Press. FULLERTON. Obstetric Nursing. 6th Ed. 45 Illua. $1.00 FULLERTON. Surgical Nursing. 3d Ed. 69 Illus. $1.00 6R0FF. Materia Medica for Nurses. With Questions for Self- Examination. 2d Edition, Revised and Improved- Just Ready. $1.25 HADLEY. Generalf Medical, and Surgical Nursing. A very Complete Manual, Including Sick-room Cookery. $1.25 HUMPHREY. A Manual for Nurses. Including General Anatomy and Physiology, Management of the Sick-room, etc. 24th Edition. 79 Illustrations. $1.00 STARR. The Hygiene of the Nursery. Including the General Regimen and Feeding of Infants and Children, and the Domes- tic Management of the Ordinary Emergencies of Early Life, Massage, etc. 6th Edition. 25 Illustrations. $1.00 TEMPERATURE AND CLINICAL CHARTS. See page 25. VOSWINEJSL. Surgical Nursing. Second Edition, Enlarged. 112 lUustrations. $1.00 WILCOX. Fever Nursing. Preparing. OBSTETRICS. CAZEAUX AND TARNIER. Midwifery. With Appendix by MuNDi). The Theory and Practice of Obstetrics, including the Diseases of Pregnancy and Partvu-ition, Obstetrical Operations, etc. 8th Edition. Illustrated by colored and other full-page Plates, and numerous Wood Engravings. Cloth, $4.50; Full Leather, $6.50 EDGAR. Text-Book of Obstetrics. By J. Cufton Edgar, M.D., Professor of Obstetrics and Clinical Midwifery, Medical Department of Cornell University, New York City, etc. 1221 Illustrations. Just Beady. Cloth, $6.00; Sheep, $7.00 FULLERTON. Obstetric Nursing. 6th Ed. lUus. $1.00 LANDIS. Compend of Obstetrics. 7th Edition, Revised by Wm. H. Wmxs, M.D., Demonstrator of Clinical Obstetrics. Jefferson Medical College. 52 Illustrations. .80; Interleaved, $1.00 WINCKEL. Text-Book of Obstetrics, Including the Pathology and Therapeutics of the Puerperal State. Illustrated. $5.00 PATHOLOGY. BLACKBURN. Autopsies. A Manual of Autopsies Designed for the Use of Hospitals for the Insane and other Public Insti- tutions. Ten fiill-page Plates and other Illustrations. $1.26 MEDICAL BOOKS. 21 COPLIN. Manual of Pathology. Including Bacteriology, Tech- nic of Post-Mortems, Methods of Pathologic Research, etc. 330 Illuatrationa, 7 Colored Platea. 3d Edition. $3.50 DA COSTA. Clinical Hematology. A Practical Guide to the Examination of the Blood. Six Colored Plates and 48 Illus- trations. Cloth, $5.00; Sheep, $6.00 LAZARUS-BARLOW. Pathological Anatomy. With 7 Colored Plates and 171 other Illustrations. $6.50 MacLEOD. The Pathology of the Skin. Colored and other Illustrations. Just Ready. $5.00 MARTIN. Manual of Pathology. Illustrated. Nearly Ready. ROBERTS. Gynecological Pathology. Illustrated. $6.00 THAYER. Compend of Special Pathology. Illustrated. .80; Interleaved, $1.00 THAYER. Manual of General and Special Pathology. 131 Illustrations. 711 pages. 2d Edition. Just Ready. $2.50 VIRCHOW. Post-Mortem Examinations. 3d Edition. .75 WHITACRE. Laboratory Text-Book of Pathology. With 121 Illustrations. $1.50 PHARMACY, Special Catalogue of Book* on Pharmacy sent free upon application. COBLENTZ. Manual of Pharmacy. A Complete Text-Book by the Professor in the New York College of Pharmacy. 2d Ed., Revised and Enlarged. 437 Illus. Cloth, $3.50; Sheep, $4.50 COBLENTZ. Volxmietric Analysis. Illustrated. $1.25 BEASLEY. Book of 3100 Prescriptions. Collected from the Practice of the Most Eminent Physicians and Surgeons — Eng- lish, French, and American. A Compendious History of the Materia Medica, Lists of the Doses of all the Officinal and Es- tablished Preparations, an Index of Diseases and their Reme- dies. 7th Edition. $2.00 BEASLEY. Druggists' General Receipt Book. Comprising a Copious Veterinary Formulary, Recipes in Patent and Pro- prietary Medicines, Druggists' Nostrums, etc. ; Perfumery and Cosmetics, Beverages, Dietetic Articles and Condiments, Trade Chemicals, Soientifio Processes, and many Useful Tables. 10th Edition. $2.00 BEASLEY. Pharmaceutical Formulary. A Synopsis of the British, French, German, and United States Pharmacopoeias. Comprising Standard and Approved Formulae for the Prepara- tions and Compounds Employed in Medicine. 12th Ed. $2.00 GREENISH. Microscopical Examination of Foods and Drugs. Illustrated. Just Ready. $3.50 ROBINSON. Latin Grammar of Pharmacy and Medicine. 4th Edition. With elaborate Vocabularies. Just Ready. $1.50 SAYRE. Organic Materia Medica and Pharmacognosy. An Introduction to the Study of the Vegetable Kingdom and the Vegetable and Animal Drugs. Comprising the Botanical and Physical Characteristics, Source, Constituents, and Pharma- copeial Preparations, Insects Injurious to Drugs, and Phar- macal Botany. With sections on Histology and Microtech- nique, by W. C. Stbvens, 374 Illustrations. Second Edition. Cloth. $4.50 22 SUBJECT CAf ALOGtJE. SCOVILLE. The Art of Compounding. Second Edition, Re- vised and Enlarged. Cloth, 82.50 STEWART. Compend of Pharmacy. Based upon "Reming- ton's Text-Book of Pharmacy." 6th Edition, Revised m Accordance with the U. S. Pharmacopoeia, 1890. Complete Tables of Metric and English Weights and Measures. .80; Interleaved, $1.00 TAVERA. Medicinal Plants of the Philippines. $2.00 UNITED STATES PHARMACOPCEIA. 7th Decennial Revision. Cloth, S2.50 (postpaid, $2.77) ; Sheep, $3.00 (postpaid, $3.27) ; Interleaved, $4.00 (postpaid, $4.50); Printed on one side of page only, unbound, $3.50 (postpaid, $3.90). Select Tables from the U. S. P. Being Nine of the Most Impor- tant and Useful Tables, Printed on Separate Sheets. .25 POTTER. Handbook of Materia Medica, Pharmacy, and Thera- peutics. 600 Prescriptions. 9th Edition. Cloth, $5.00; Sheep, $6.00 PHYSIOLOGY. BIRCH. Practical Physiology. An Elementary Class Boole. 62 Illustrations. $1-75 BRUBAKER. Text-Book of Physiology. Illus. Nearly Ready. BRUBAKER. Compend of Physiology. 11th Edition, Revised and Enlarged. Illustrated. .80; Interleaved, $1.00 JONES. Outlines of Physiology. 96 Illustrations. $1.50 KIRKES. Handbook of Physiology. 17th Authorized Edition. Revised, Rearranged, and Enlarged. By Prot. W. D. Halli- burton, of Kings College, London. 681 Illustrations, some of which are in colors. Cloth, $3.00 ; Leather, $3.75 LANDOIS. A Text-Book of Human Physiology. Including Histology and Microscopical Anatomy, with Special Reference to the Requirements of Practical Medicine. 5th American, translated and edited from the last German Edition by A. P. Brubaker, M.D., and A. A. Eshner, M.D. In Press. STARLING. Elements of Human Physiology. 100 Illus. $1.00 STIRLING. Outlines of Practical Physiology. Including Chem- ical and Experimental Physiology, with Special Reference to Practical Medicine. 3d Edition. 289 Illustrations. $2.00 TYSON. CeU Doctrine. Its History and Present State. $1.60 PRACTICE. BEALE. On Slight Ailments : their Nature and Treatment. 2d Edition, Enlarged and Illustrated. $1.25 COHEN. Physiologic Therapeutics. The Treatment of Disease by Methods other than Drug-giving. See page 17. FAGGE. Practice of Medicine. 4th Edition, by P. H. Pte- Smith, M.D. 2 volumes. Vol. I, $6.00; Vol. II, $6.00 FOWLER. Dictionary of Practical Medicine. By various writers. An Encyclopaedia of Medicine. Cloth, $3.00; Half Moroeco, $4.00 MEDICAL BOOKS. IS GOULD AND PYLE. Cyclopedia of Practical Medicine and Surgery. A Concise Reference Handbook, with particular Reference to Diagnosis and Treatment. Edited by Drs. Gould and Ptlb, Assisted by 72 Special Contributors. Illus- trated, one volume. Large Square Octavo, Uniform with "Gould's Illustrated Dictionary." Sheep or Half Mor., $10.00; with Thumb Index, $1L00 Half Russia, Thumb Index, $12.00 4^ Complete descriptive circular free upon application. GOULD AND PYLE'S Pocket Cyclopedia of Medicine and Sur- gery. Based upon the above and Uniform with "Gould's Pocket Dictionary." Full Limp Leather, Gilt Edges, Round Corners, $1.00; with Thumb Index, $1.25. HUGHES. Compend of the Practice of Medicine. 6th Edition, Revised and Enlarged. Part I. Continued, Eruptive, and Periodical Fevers, Disease of the Stomach, Intestines, Peritoneum, Biliary Passages, Liver, Kidneys, etc., and General Diseases, etc. Part II. Diseases of the Respiratory System, Circulatory System, and Nervous System ; Diseases of the Blood, etc. Price of each part, .80; Interleaved, $1.00 Physician's Edition. In one volume, including the above two parts, a Section on Skin Diseases, and an Index. 6th Re- vised Edition. 625 pp. Full Morocco, Gilt Edge, $2.25 TAYLOR. Practice of Medicine. 6th Edition. $4.00 TYSON. The Practice of Medicine. By James Ttson, m.ix. Professor of Medicine in the University of Pennsylvania. Complete Systematic Text-book, with Special Reference to Diagnosis and Treatment. 3d Edition, Enlarged and Revised. Colored Plates and 125 other Illustrations. Cloth, $5.50; Leather, $6.50 STOMACH. INTESTINES. FENWICK. Cancer of the Stomach. Just Ready. $3.00 HEMMETER. Diseases of the Stomach. Their Special Pathol- ogy, Diagnosis, and Treatment. With Sections on Anatomy, Analysis of Stomach Contents, Dietetics, Surgery of the Stom- ach, etc. 3d Edition, Revised. With 15 Plates and 41 other Illustrations, a number of which are in colors. Cloth, $6.00; Sheep, $7.00 HEMMETER. Diseases of the Intestines. Their Special Path- ology, Diagnosis, and Treatment. With Sections on Anatomy and Physiology, Microscopic and Chemic Examination of In- testinal Contents, Secretions, Feces and Urine, Intestinal Bacteria and Parasites, Surgery of the Intestines, Dietetics, Diseases of the Rectum, etc. With Full-page Colored Plates and many other Original Illustrations. 2 volumes. Octavo. Price of each volume, Cloth, $5.00; Sheep, $6.00 SKIN. BULKLEY. The Skin in Health and Disease. Illustrated. .40 CROCKER. Diseases of the Skin. Their Dejcription, Pathol- ogy, Diagnosis, and Treatment, with Special Reference to the Skin Eruptions of Children. 3d Edition, Thoroughly Revised. With New Illustrations. Cloth, $5.00 ; Sheep, $6.00 MacLEOD. The Pathology of the Skin. Colored and other Illustrations. $5.00 lA SUBJECT CATALOGUE. SCELA.MBER6. Diseases of the Skin. 3d Edition, Revised and Enlarged. 106 lUuBtrationa. Beine No. 16 ? Qiiii-Compend? Series. Jxut Ready. Cloth, .80; Interleaved, $1.00 VAW HARLINGEN. On Skin Diseases. A Practical Manual i* of Dianiosis and Treatment, with Special Reference to Differ- W ential Diagnosis. 3d Edition, Revised and Enlarged. With V Formulae and 60 Illustrations, some of which are printed in ^ colors. $2.75 SURGERY AND SURGICAL DISEASES (see also Urinary Organs). BERRY. Diseases of the Thyroid Gland. Illustrated. $4.00 BUTLIN. Operative Surgery of Malignant Disease. 2d Edi- tion. Illustrated. Octavo. $4.50 CASPER AND RICHTER. Fimctional Kidney Diagnosis. $1.50 DAVIS. Bandaging. Its Principles and Practice. 163 Original Illustrations. $1.50 DBAVER. Sxirgical Anatomy. A Treatise on Human Anatomy in its Application to Medicine and Surgery. With about 500 very handsome full-page Illustrations Engraved from Original Drawings made by special Artists from Dissections prepared for the purpose. Three volumes. Royal Square Octavo. By Sxibacription only. .Novo Ready. Half Morocco or Sheep, $24.00; Half Russia, $27.00 DEAVER. Appendicitis : its Symptoms, Diagnosis, Pathologry, Treatment, and Complications. Elaborately Illustrated with Colored Plates and other Illus. 3d Edition. Nearly Ready. DOUGLAS. Surgical Diseases of the Abdomen. Illustrated by 20 Full-page Plates. Juit Ready. Cloth, $7.00; Sheep, $8.00 DULLES. What to do First in Accidents and Poisoning. 5th Edition. New lUustrations. $1.00 FULLERTON. Surgical Nursing. 3d Ed. 69 Illus. $1.00 HAMILTON. Lectures on Tximors. 3d Edition. $1.25 HEATH. Minor Surgery and Bandaging. 12th Edition, Re- vised and Enlarged. 195 Illus., Formulae, Diet List, etc. $1.50 HEATH. Clinical Lectures on Sxirgical Subjects. Second Series. $2.00 HORWITZ. Compend of Surgery and Bandaging. Including Minor Surgery, Amputations, Fractures, Dislocations, SurgicfU Diseases, etc., with Differential Diagnosis and Treatment. 5th Edition, very much Enlarged and Rearranged. 167 Illus., 98 Formulae. Cloth, .80; Interleaved, $1.00 JACOBSON. Operations of Surgery. 4th Ed., Enlarged. 550 Illus. Two volumes. Cloth, $10.00; Leather, $12.00 KBAY. Medical Treatment of Gall-Stones. $1.25 KEHR. Gall-stone Disease. Translated by William Wotktn* Sbthouk, m.d. $2.50 MAKINS. Surgical Experiences in South Africa. 1899-1900. Illustrated. $4.00 MAYLARD. Surgery of the Alimentary Canal. 97 lUiistrations. 2d Edition, Revised. $3.00 MEDICAL BOOKS. 25 HOULLIN. Text-Book of Surgery. With Special Reference to Treatment. 3d American Edition. Revised and edited by John B. Hamilton, m.d., ll.d., Professor of the Principles of Surgery and Clinical Surgery, Rush Medical College, Chicago. 623 Illuatrations, many of which are printed in colors. Cloth, $6.00; Leather, $7.00 SMITH. Abdominal Surgery. Being a Systematic Description of all the Principal Operations. 224 Illustrations. 6th Edi- tion. 2 volumes. Cloth, $10.00 VOSWTNKEL. Surgical Nursing. Second Edition, Revised and Enlarged. Ill Illustrations. $1.00 WALSHAM. Manual of Practical Surgery. 7th Ed., Revised and Enlarged. 483 Engravings. 950 pages. $3.50 TEMPERATURE CHARTS, ETC. GRIFFITH. Graphic Clinical Chart for Recording Tempera- ture, Respiration, Pulse, Day of Disease, Date, Age, Sex, Occu- pation, Name, etc. Printed in three colors. Sample copies free. Put up in loose packages of fifty, 50 cts. Price to Hospitals, 500 copies, $4.00; 1000 copies, $7.50. KEEN'S Clinical Charts. Seven Outline Drawings of the Body, on which may be marked the Course of Disease, Fractures, Operations, etc. Each Drawing may be had separately, twenty-five to pad, 25 cents. THROAT AND NOSE (see also Ear). COHEN. The Throat and Voice. Illustrated. .40 HALL. Diseases of the Nose and Throat. 2d Edition, Enlarged. Two Colored Plates and 80 Illustrations. $2.75 HOLLOPETER. Hay Fever. Its Successful Treatment. $1.00 KNIGHT. Diseases of the Throat. A Manual for Students. Illustrated. Just Ready. $3.00 KYLE (J. J.). Diseases of the Ear, Nose, and Throat. A Com- pend for Students. Illustrated. .§0; Interleaved, $1.00 McBRIDE. Diseases of the Throat, Nose, and Ear. With Col- ored Illustrations from Original Drawings. 3d Ed. $7.00 POTTER. Speech and its Defects. Considered Physiologically, Pathologically, and RemediaUy. $1.00 URINE AND URINARY ORGANS. ACTON. The Functions and Disorders of the Reproductive Organs in Childhood, Youth, Adult Age, and Advanced Life, Considered in their Physiological, Social, and Moral Relations. 8th Edition. $1.75 CASPER AND RICHTER. Functional Kidney Diagnosis. $1.50 HOLLAND. The Urine, the Gastric Contents, the Common Poisons, and the Milk. Memoranda, Chemical and Micro- scopical, for Laboratory Use. Illustrated and Interleaved. 6th Edition. $1.00 KLEEN. Diabetes and Glycosuria. $2.50 26 SUBJECT CATALOGUE. MEMMINGER. Diagnosis by the Urine. 2d Edition. 24 Illus- trations. $1.00 MORRIS. Renal Surgery, with Special Reference to Stone in the Kidnev and Ureter and to the Surgical Treatment of Calculous Anuria. Illustrated. $2.00 MOULLIN. Enlargement of the Prostate. Its Treatment and Radical Cure. 2d Edition. Illustrated. $1.75 MOULLIN. Inflammation of the Bladder and Urinary Fever. Octavo. $1.50 SCOTT. The Urine. Its Clinical and Microscopical Examina- tion. 41 Lithographic Plates and other Illustrations. Quarto. Cloth, $5.00 TYSON. Guide to Examination of the Urine. For the Use of Physicians and Students. With Colored Plate and Numerous niustrations engraved on wood. 10th Edition, Revised, En- larged, and paruy Rewritten. With New Illustrations. Jvst Beady. $1.50 VAIf KUYS. Chemical Analysis of Urine. 39 Illus. $1.00 VENEREAL DISEASES. GOWERS. Syphilis and the Nervous System. $1.00 STURGIS AND CABOT. Student's Manual of Venereal Diseases. 7th Revised and Enlarged Edition. 12mo $1.25 VETERINARY. BALLOU. Eqtiine Anatomy and Physiology. 29 Graphic Illustrations. .80; Interleaved, $1.90 JACOBSON. The Operations of Surgery. By W. H. A. Jacobson, F.R.C.S., Surgeon to Guy's Hospital ; Consulting Surgeon Royal Hospital for Children and Women ; and F. J. Steward, f.r.c.s., Assistant Surgeon Guy's Hospital. Fourth Edition — Revised, Enlarged, and Improved. 550 Illustrations. Two Volumes, Octavo, 1524 pages. Cloth, $10.00; Sheep, $12.00 " The important anatomical points are clearly set forth, the conditions indicating or contraindicating operative interference are given, the details of the operations themselves are brought forward prominently, and frequently the after-treatment is considered. Herein is one of the strong points of the book."— - Nev York Medical Journal. "We know of no series of books issued by any house that so fully meets our approval as these ? Quiz-Compends?. They are well arranged, full and concise, and are really the best line of text-books that could be found for either student or practitioner." — Southern Clinic. BLAKISTON'S ? QUIZ-COMPENDS? The Best Series of Manuals for the Use of Students. Price of each, Cloth, .80. Interleaved, for taking Notes, $1.00 These Compends are based on the most popiilar text-books and the lectures of prominent professors, and are kept constantly revised, so that they may thoroughly represent the present state of the subjects upon which they treat. The authors have had large experience as Quiz-Masters and attaches of colleges, and are well acquainted with the wants of students. They are arranged in the most approved form, thorough and concise, containing nearly 1000 illustrations and lithograph plates, inserted wherever they could be used to advantage. Can be used by students of any coUege. They contain information nowhere else collected in such a condensed, practical shape. No. I. POTTER. HUMAN ANATOMY. Seventh Edition. 138 Illustrations and 16 Plates of Nerves and Arteries. No. 2. HUGHES. PRACTICE OF MEDICINE. Part I. Sixth Edition, Enlarged and Improved. No. 3. HUGHES. PRACTICE OF MEDICINE. Part H. Sixth Edition, Revised and Improved. No. 4. BRUBAKER. PHYSIOLOGY. Eleventh Edition. Illua. No. 5. LANDIS. OBSTETRICS. Seventh Edition. 52 Illua. No. 6. POTTER. MATERIA MEDICA, THERAPEUTICS, AND PRESCRIPTION WRITING. Sixth Revised Edition. No. 7. WELLS. GYNECOLOGY. Third Edition. 140 Illus. No. 8. GOULD AND PYLE. DISEASES OF THE EYE. Second Edition. Refraction, Treatment, Surgery, etc. 109 Illus. No. 9. HORWITZ. SURGERY. Including Minor Surgery, Bandaging, Surgical Diseases, Differential Diagnosis and Treatment. Fifth Edition. With 98 Formula and 71 Illus- trations. No. 10. LEFFMANN. MEDICAL CHEMISTRY. Fourth Edi- tion. Including Urinalysis, Animal Chemistry, Chemistry of Milk, Blood, Tissues, the Secretions, etc. No. II. STEWART. PHARMACY. Fifth Edition. Based upon Prof. Remington's Text-Book of Pharmacy. No. 12. BALLOU. EQUINE ANATOMY AND PHYSIOLOGY 29 graphic Illustrations. No. 13. WARREN. DENTAL PATHOLOGY AND DENTAL MEDICINE. Fourth Edition, Illustrated. No. 14. HATFIELD. DISEASES OF CHILDREN. 3d Edition. No. 15. THAYER. GENERAL PATHOLOGY. 78 Ulus. No. 16. SCHAMBERG. DISEASES OF THE SKIN. Third Edition, Revised and Enlarged. 106 lUustrationa, No. 17. GUSHING. HISTOLOGY. lUustrated. In Press. No. 18. THAYER. SPECIAL PATHOLOGY. 34 Illustrations. No. 19. KYLE. DISEASES OF THE EAR. NOSE, AND THROAT. Illustrated. 27 DA COSTA Clinical Hematology A Practical Guide to the Examination of the Blood by Clinical Methods. With Reference to the Diagnosis of Disease. With Colored Illustrations. Cloth, ^5.00 *^*A new, thorough, systematic, and comprehensive work, its purpose being, first, to show how to examine the blood, and second, how to diagnose from such examination diseases of the blood itself and general diseases. The author' s aim has been to cover not alone the field of original research, but to supply a book for the student, the hospital physician and the general practitioner. It will be found wanting in none of these respects. OERTEL Medical Microscopy A GUIDE TO DIAGNOSIS, ELEMEN- TARY LABORATORY METHODS, AND MICROSCOPIC TECHNIC By T. E. Oertel, M.D., Professor of Pathology and Clinical Microscopy, Medical Depart- ment, University of Georgia. WITH 131ILLUSTRATIONS. i2mo. Cloth, $2.00 28 The Pocket Cyclopedia, of Medicine and Surgery Full Limp Leather, Round Corners, Gilt Edges, $1.00 With Thumb Index, $1.25 Uniform tvith ^* Gould's Pocket Dictionary" A concise practical volume of nearly 600 pages, containing a vast amount of infor- mation on all medical subjects, including Diagnosis and Treatment of Disease, with Formulas and Prescriptions, Emer- gencies, Poisons, Drugs and Their Uses, Nursing, Surgical Procedures, Dose List in both English and Metric Systems, etc. By Drs. Gould and Pyle Based upon their large ^* Cyclopedia of Medicine and Surgery.*' ^ t^ ^ *^* This is a new book which will prove of the greatest value to students. It is to the broad field of general medi- cal information what "Gould's Pocket Dictionary" is to the more special one of definition and pronunciation of words. The articles are concise but thorough, and arranged in shape for quick reference. In no other book can be found so much exact detailed knowledge so conveniently classified, so evenly distributed, so methodically grouped. It is Multum in Parvo. Sample Pages Free. 29 A NEW EDITION Crocker on the Skin The Diseases of the Skin. Their Description, Pathology, Diagnosis, and Treatment, with Special Reference to the Skin Eruptions of Children. By H. Radcliffe Crocker, M.D., Physician to the Department of Skin Diseases, Uni- versity College Hospital, London. With new Illustrations. Third Edition, Rewritten and Enlarged OCTAVO. JUST READY? CLOTH, $5.00 *^* This new edition will easily hold the high position given the previous printings. The author is a member of American, English, French, German, and Italian Dermato- logical Societies, and a recognized authority the world over. STURGIS— MANUAL OF VENEREAL DISEASES By F. R. Sturgis, m.d.. Sometime Clinical Professor of Venereal Diseases in the Medical Department of the Uni- versity of the City of New York. Seventh Edition, Revised and in Part Rewritten by the Author and Follen Cabot, M.D., Instructor in Genito-Urinary and Venereal Diseases in the Cornell University Medical College. i2mo. 216 pages. Cloth, $1.25 *^* This manual was originally written for students' use, and is as concise and as practical as possible. It pre- sents a careful, condensed description of the commoner forms of venereal diseases which occur in the practice of the general physician, together with the most approved remedies. 80 FOR THE DISSECTING ROOM Holden*s Anatomy — Seventh Edition 320 Illustratioi\s A Manual of the Dissections of the Human Body. By John Langton, f.r.c.s. Carefully Revised by A. Hewson, m.d., Demonstrator of Anatomy, Jefferson Medical College, Phila- delphia, etc. 320 Illustrations. Two small compact vol- umes. i2mo. Vol. I, Scalp, Face, Orbit, Neck, Throat, Thorax, Upper. Extremity. 435 pages. 153 Illustrations. Oil Cloth, $1.50 Vol. II. Abdomen, Perineum, Lower Extremity, Brain, Eye, Ear, Mammary Gland, Scrotum, Testes. 445 pages. 167 Illustrations. Oil Cloth, ^1.50 Each volume sold separately. Hughes a^ivd Keith — Dissections IllustraLted A Manual of Dissections by Alfred W. Hughes, m.b., M.R.c.s. (Edin. ), late Professor of Anatomy and Dean of Medical Faculty, King's College, London, etc., and Arthur Keith, m.d., Joint Lecturer on Anatomy, London, Hospital Medical College, etc. In three parts. With 527 Colored and other Illustrations. I. Upper and Lower Extremity. 2i2> Plates, 1 16 other Illustrations. Cloth, $3.00 II. Abdomen. Thorax. 4 Plates, 149 other Illus- trations. Cloth, ^3.00 III. Head, Neck, and Central Nervous System. 16 Plates, 204 other Illustrations. Cloth, $3.00 Each voluvie sold separ'ately. *^ The student will find it of great advantage to have a ''Dissector" to supplement his regular text-book on anatomy. These books meet all requirements, and as they can be purchased in parts as wanted, the outlay is small. "*> 31 EDGAR'S OBSTETRICS A NEW TEXT -BOOK 1 2 2 1 Illustrations Edgar's Obstetrics excels all other works on this subject in completeness, in uni- formity and consistency in arrangement, thoroughness and clearness in handling details, and in the number and usefulness of its illus- trations. OCTAVO. CLOTH, ^6.005 SHEEP, ^7.00 COLUMBIA UNIVERSITY LIBRARIES 0041075048