Indications and Contraindications for the Applica- notice of the great experimental pathologist, Julius Cohn- tion the Bead Test.—The bead test should be used in heim, who soon took Weigert as his assistant at Breslau. of The illness of the master threw a of the work all cases in which a more of the large part daily thorough knowledge of the institute and of the dead-house on who soon functions of the is desired. Weigert, digestive apparatus developed under the critical eyes of his teacher into a path- The bead test is not permissible in all pronounced ologic anatomist possessed of superior technic and objective stenoses of the digestive tract, stricture of the esophagus, criticism. One might have supposed that Cohnheim's genius stomach and intestine. would have led Weigert into the growing and promising field of experimental pathology. There are two reasons why this proved not to be the case. Weigert early attained an in- dividual view of medicine and of the methods most likely to advance it. He believed that pathologic histology might be materially advanced by the development of improved methods THE COLLECTED WORKS OF CARL WEIGERT. of staining, and from the outset was so successful in devis- ing valuable histologie methods that he did not care to turn E. K. Dunham, M.D. and C. A. Herter, M.D. aside to join Cohnheim in his experimental studies. That NEW YORK CITY. Weigert's great master helped him by encouragement and The publication of the collected works of the great patho- suggestion is certain, but it is equally true that the young logic anatomist, Carl Weigert, is a notable event for the pathologist worked out his own salvation in all that pertained further and many persons interested in the progress of discovery and to histology. His independence extended still was thought in medicine, for between the covers of these carefully early reflected in his well considered views of general biologic edited volumes may be found the records of methods of inves- laws. That Cohnheim was influenced by the original thought tigation, of observations and of generalizations that are exert- of his pupil can not be doubted. For example, it appears to hav- ing a deep and lasting influence on medical science. This have been Weigert's influence that led the master, after influence is the more remarkable because it emanates from ing met with failure, to repeat with success his experiment on of tubercles. But a man who was singularly modest and gentle, unapt to con- the inoculation the strong individuality tend for the prestige of his views\p=m-\aman who spoke his of Weigert as an original worker was not the sole obstacle message to science not from the vantage-ground of the to following the paths opened by the great experimentalist. authority that belongs to high academic rank but from the A certain innate tenderness of nature, quite unmixed with him an to on more obscure and independent focus of an unpretentious false sentiment, gave aversion experimenting laboratory without university connections. So intimate is animals—an aversion similar to that which made it impos- the relation between the character of this man and the work sible for Pasteur to do vivisection. Rieder tells us that the which he did that it seems fitting to sketch, in a few words, rabbits in the Senkenberg Institute led an enviable existence, his life and personality before undertaking to review his con- for when they came in contact with their master it was to tributions to biologic science. share his mid-day meal. When in was invited to fill the chair of A SKETCH OF HIS LIFE. Cohnheim, 1878, pathologic anatomy at the University of Leipsig, Weigert small town that in It was the Silesian of Milnsterberg went with him as extraordinarius, a position which he filled the a decade the 1845, gave Carl Weigert to world. Within until the death of the master, in 1885. It was during this a to same district gave Weigert cousin destined develop great period that Weigert made some of hin best contributions to an and to be and gifts as investigator his sympathetic help- pathologic anatomy; and perhaps no work of his has had a ful colleague through life—Paul Ehrlich. In childhood Weigert wider influence on the of medicine than the dis- it progress showed studious habits and exceptional filial affection, but covery in 1882 of a method by which the medullary sheaths does not appear that he early gave indications of his genius of nerves can be sharply differentiated from the axis cylinder. as an investigator. During the medical school period he de- On Cohnheim's death, Weigert undertook the duties incidental veloped a taste for research and had the good fortune after to teaching pathologic anatomy at the Senkenberg Institute to passing the state examinations be associated with Virchow in Frankfurt. Here, in the course of nearly twenty years' as his amanuensis. He now came under the influence of the tenure of the directorship of the institute, he quietly continued physiologist, Heidenhain, and later worked with Waldeyer, his admirable researches in pathologic anatomy and placed who had been a of the vitalistic himself pupil great physi- many young investigators under an enduring sense of grati- ologist. tude for the inspiration gained from his guidance. The Franco-Prussian War broke rudely into Weigert's Although the Frankfurt period was one of happiness for studies, but his experience as surgeon to his regiment much Weigert he never wholly recovered from the disappointment of widened his view of life. In later days he loved to tell of failing to succeed Cohnheim in the professorship at the Uni- his military adventures during the seige of Paris and of his versity of Leipsig, and throughout his life the failure caused subsequent visit to England. During the years immediately him hours of depression. Weigert knew, what was equally to following the war, Weigert gave considerable attention well known to the best qualified judges, that he was the clinical medicine in the Breslau Clinic and this education person best fitted to fill the chair vacated by Cohnheim, de- and served him well in later life, when, with wonderful skill spite the fact that he was not an experimental pathologist. insight, he indicated to the physicians of Frankfurt, in his The thought that his colleagues had rejected him, very largely talks in the dead-house, the relations between the pathologic for the reason of his being a Jew, was a standing offense to findings and the clinical phenomena. It was during this early his sense of justice. That his great merits were really in a Breslau period that Weigert made his admirable investiga- measure recognized by members of the Leipsig faculty seems tions of the eruption in smallpox, in connection with which probable. They offered him a public call to the university on he developed the conception of cell death or coagulation condition that he would not accept it—a proposition which methods of bacteria in necrosis and originated staining tissues. naturally proved highly distasteful to Weigert. It is an in- in its of new facts This research was rich yield methods, and, dication of the superior nature of the man that in a manu- the ideas worked out by young investigator. script dealing especially with the methods of making ap- But Weigert at this time made little impression on patho- pointments in universities, found after Weigert's death, this logic anatomists, not because his investigations were not difficult subject is dealt with in a thoroughly objective and original, but because, as Lichtheim says, they were too orig- judicial way, without the slightest intrusion of personal inal. His work on smallpox, nevertheless, brought him to the feeling. Weigert resembled his great predecessor in pathologic Including a review of the book published with the co\l=o"\peration anatomy, Virchow, in not being a good teacher for the man of and Paul Ehrlich and edited by Robert Rieder. Ludwig Edinger of and poor He had none of the In two with three 584 average ability training. quarto volumes lithographic plates. Pages of the schoolmaster and could not talk and 744. Price, 50 marks. Berlin: J. Springer, 1906. didactic ways for

Downloaded From: http://jama.jamanetwork.com/ by a Oakland University User on 06/08/2015 artistic effect. It was thus fortunate that in Frankfurt he to be unimportant. On one occasion, when asked about his was not expected to give instructions to beginners in medicine. work he said, "I am working away at the old things—small, The special students who came to his little laboratory pre- insignificant things. I realize -„hat I can not compete with pared to do serious work found that Weigert possessed, in my younger colleagues. Look at my cousin Paulus (mean- the highest degree, the power of intellectually stimulating ing Ehrlich) and his immunity work. How can I keep up others and of making their work fruitful. His influence as a with that? Then again this modern chemical pathology which teacher extended far beyond the field of medicine and deeply requires so much special training. It is all right for Paulus affected the philosophic outlook of many a student. The with his extraordinary memory for those hexagons (benzene persons who came into close contact with Weigert recognized ring derivatives), but I can not do it." that the society of the joyous yet earnest man was ever an The attitude of the universities toward Weigert doubtless education and a delight. contributed to his despondency and even made him at times As an investigator, Weigert belongs in a select group of doubt somewhat hi3 powers, his knowledge and hjs worth. a and deliberate, careful workers, who regard problem calmly During the "period of nearly twenty years following Cohn- from every side while bringing to bear extraordinary powers heim's death he did not once receive a university call—a fact in of analysis and a high degree of ingenuity overcoming difficult to understand when one realizes how greatjy his figure technical difficulties. The manner in which he developed his towers above nearly all contemporary pathologic anatomists. Intricate methods of staining shows his capacity for grasp- He sought neither fame nor honors, but it was hard to be and ing principles applying them to special ends. His studies slighted for men of clearly inferior capacity. It is probably Of inflammation and of new growths reveal the constructive true that the scant appreciation shown him by the faculties philosophic mind, which derives its highest satisfaction in the was in part owing to lack of forcefulness and will power in search for fundamental in a laws the midst of bewildering certain directions. Rieder aptly says of him: "He had no maze of was that facts. Weigert's mind one advanced step idea how one makes a career and how necessary it is to-day by step and took few risks. His mind was almost too well to associate one's own advantage with that of others." Weigert ordered to lead him into the experimental ventures that pro- clearly had the amiable faults of the over-sensitive idealistic duce the most never strikingly original results. He published student whose modesty makes it impossible for him to ap- until he was that he satisfied had done the best work 'of praise his own worth. which he was and when he said to one of his capable, pupils In 1904 Weigert was looking forward with eagerness to a in 1887, "One can never publish anything late enough," he visit to the United States, to "the land of unlimited possi- gave the clue to his attitude toward research. In all that bilities," as he liked to call it. It was expected that he would he had in mind soundness and conscientious did, Weigert per- lecture at the Johns Hopkins Medical School on certain topics formance. The extreme of this sometimes had the tendency in general pathology on which he had long pondered. It is detrimental effect on his work that may come from an ex- certain that he would have been enthusiastically received by conscientiousness. For was so anxious aggerated example, he his many friends and pupils and the visit would surely have to the of his stain that he let perfect reliability neuroglia helped him to throw off his doubts as to his own merit. "It many more important subjects rest while he pursued an end will bring fresh wind to his sails," said his cousin, Ehrlich, which a he could hope to attain only by large admixture of in speaking of the proposed visit. But Fate willed it other- fortune with effort. Thus he tended at times good intelligent wise. In the summer of 1904, at the close of a Sunday agree- to In the admirable critical reviews which grow unproductive. ably spent with his friends, Weigert retired to his room to wrote, one finds the same conscientious Weigert performance read, as was his wont. The next morning his lifeless body as in his research work and the same interest in the percep- was found. He had apparently had no premonitions of what tion of fundamental The reviews on principles. chemotaxis, was impending. Indeed, during the last days of his life his on new theories of and on antitoxin heredity immunity, are companions had observed with pleasure a return of the buoy- cases in and all bear the of an mind. point imprint original ancy of spirit that had characterized his earlier days. Weigert was a man of medium with a well- stature, large, The death of Carl Weigert was in every sense premature. head. In his later he was inclined shaped years slightly Through it humanity lost a singularly simple, noble toward His brown were ex- spirit corpulence. large eyes beautiful, and the science of medicine was robbed of one of its greatest pressing gentleness and great intelligence. His sympathetic, lights. open and which gave him interest in all kinds joyous nature, » weigert's works. of human endeavor and all sorts of people, made him greatly In these two handsome works liked. He mixed freely with scientific and practical men of volumes, Weigert's fill 1,328 all kinds. He often amused his more intimate friends with pages, which are preceded by a preface and 140 pages devoted his powers of ventriloquism and mind-reading, but his greatest to a sketch of the master's life, tributes to his services in and and and social gift lay in a rare talent for telling stories full of a neurology histology by Edinger Ehrlich, a naive humor and kindliness. chronologic list of Weigert's scientific publications in which is to Up to the time of his sudden death, from coronary throm- reference made 97 titles. bosis, he enjoyed good health and remained steadfastly at It would be a hopeless task to attempt a detailed review work. As his body lay on its bier there stood filtering in the of this rich collection. It is possible merely to select certain laboratory a solution designed to improve the neuroglia stain. of these works for particular mention and this may be done In the last years of his life Weigert devoted much thought almost at random, where all the material bears the marks to the pathogenesis of new growths and it was his intention of deep study and careful exposition. The style is exceed- to embody his views in a publication dealing with the sub- ingly lucid and on the whole simple, but so concise and idio- ject from the standpoint of the laws of cell development. He matic as to render translation into exactly equivalent Eng- was deeply interested in De Vries' great work on Mutation lish a matter of great difficulty. are under and believed it shed important light on some questions con- Weigert's works grouped six i.eads: "Bioplastik," nected with the aberrant growth of animal cells. One of the "Pathologic Anatomy," "Pathologic Histology," "Bacteriology," reviewers visited Weigert in his laboratory not long before "Neurology and Microtechnic," and 'Varia;" the last includ- his death and found him sitting on a high stool with legs ing an obituary of Julius Cohnheim, his master, an article folded under him tailor-fashion, perusing De Vries'. "I read on mind-reading and some remarks referring to the establish- this work," he said, "over and over again. Parts of it I find ment of an institute for experimental therapy in Frankfurt. very difficult to understand because it is so technical, but I This division does not follow the chronological order, but do not wish to lose a line of it or miss an idea, and so I brings together those contributions which are naturally re- stick to it." lated to each other. In some respects the articles included Despite his many and great contributions to medical science, under the collective title "Bioplastik" are of particular inter- Weigert in his later days had periods of depression in which est because they serve admirably to illustrate the breadth of he suffered great discouragement in regard to his capacity for thought manifested by Weigert throughout his writings and work. He felt his powers waning and imagined his researches his analytical, critical and constructive abilities.

Downloaded From: http://jama.jamanetwork.com/ by a Oakland University User on 06/08/2015 A striking example of the philosophical inclination of biologie phenomena, and to make useful, conservative and Weigert's mind to unify, systematize and correlate the knowl- guarded generalizations. One would be tempted, in this con- edge he possessed is contained in the 186 pages bearing the nection, to dwell upon Weigert's trained powers of imagina- caption "Attempt at a general pathologic morphology based tion which led him to seek consistent hypotheses as an aid on the normal," which is the seventh and final division of that to research, were it not that the mere enumeration already part of the whole work designated as "Bioplastik." This study made of the titles of the "Bioplastic" papers reveal this comprises fifteen chapters, only five of which may be re- quality of his mind; a quality" admirably blended with a garded as completed, in at least a tentative form, to the critical judgment. satisfaction of the author, for in an interesting foot note of That Weigert was an expert histologist, hardly calls for the editor's there is mention of Weigert's characteristic habit mention. His services to that branch of medical science are of repeatedly revising his writings. An enumeration of these well known. The studies of tissue-changes in coagulation chapters is all that is permitted by our space, but it will necrosis rested upon this technical knowledge, but his widest suffice to indicate the interest and value of this contribution, influence in this direction was exerted by his elaboration of as well as the methodical way in which Weigert developed methods of staining with a view to identifying the various his ideas: constituents of objects subjected to microscopic examination. 1. An Introduction and Plan. His writings on these topics are embraced in the 345 pages 2. Causality of Vital Phenomena. included in the fourth and fifth divisions of this collection: 3. and General Considerations Concerning Function Matter. and and Microteehnic." The bac- 4. Origin of Living Matter. "Bacteriology" "Neurology 5. Evolution and Epigénesis. tériologie papers are not numerous and do not occupy more 6. Idioplasm. than 70 pages of a volume containing 774 pages. The first 7. The Non-idioplastlc Germ-Constituents. paper is one in 1871 on the bacteria 8. The of the Germ-Potentialities In and bactériologie published Multiplicity Phytogeny as • the is of interest Ontogeny. in skin in smallpox. This paper mark- 9. The Alleged Totlpotentlality of the Idioplasm of Somatic ing the first discovery of bacteria in tissues. Weigert shows Cells. his excellent judgment in this instance in not falling into the 10. Remarks on the Nature of the Changes In the Idioplasm error of concluding that smallpox is due to the micrococci During Ontogenesis. in lesions of disease. The 11. External Conditions Activating Latent Idioplastic Rudiments. wliich he discovered the this fol- 12. Bloplastlc Phenomena. Kinetic and Potential Bioplastlc lowing paper is one on a mycosis in a newly born child and Energy. has to do with the coloration of bacteria. In 1881 Weigert 13. Regeneration. an on the technic of 14. The Obstacles to Growth Concerned In Regeneration. published important paper microscopic 15. Idioplastic Activities in Regeneration. investigations of bacteria in which he devotes special atten- tion to methods of Considerable is devoted to We have selected this study from among those classed as staining. space methods of of bacteria in sections. This com- bioplastic, for more detailed notice, partly because it is the investigation munication also contains a section on the of the final word from this liberal thinker upon these subjects, significance of bacteria. The author out here the impor- partly because it is a posthumous work, not published else- dyeing brings tance of with acetic acid or where. The other works in this the edi- drying tissues strong potassium placed category by in order to render the bacteria of tors, with the dates of publication, are: hydroxid capable taking stains in those cases where have failed to be 1. 1880 and 1886. they readily Inflammation, is to that con- 2. Vital Phenomena of Cells Under Pathloglc Conditions, 1886. colored. It interesting note although Weigert 3. New Problems In Pathologic Anatomy, 1896. siders the introduction of the anilin dyes as extremely im- 4. New Theories of Heredity, 1887. portant in detecting the presence of bacteria in tissues, he 5. Recent Works on the Theory of Antitoxic Immunity, 1898. does not draw the conclusion that the failure to take up color 6. on In Natural Chats the Methods of Research Science, 1898 of In (first published after Welgert's death). necessarily means the absence micro-organisms. other words, he recogni.es that further experiments are At the risk of exceeding the limits to a review, we clearly proper to result in the discovery of methods which will render can not forbear making brief mention of the work on inflam- likely visible micro-organisms which remain untouched even by the mation. The origin and foundations of our conception of this methods developed by himself. varied process are subjected to a critical examination based greatly improved In 1887 a controversial paper of consid- on an historical study of the modifications that conception has Weigert published erable interest with the bacteria passed through, as insight into has devel- dealing question. Although biologic processes the doctrines for which he contests have since been estab- oped. This constructively critical survey of past achievements long it is to read this paper even at the present leaves the wholesome impression on the reader's mind that lished, interesting as an of criticism of the contentions knowledge is still in process of evolution and that the final day example searching word is not yet uttered. Having, nevertheless, classified and of a writer named Hiller, who energetically contended that his results with the inoculation of certain bacteria defined in this manner the known factors constituting our negative constituted a that these and most other bacteria are conception of the inflammatory process, the author analyzes proof innocuous. In the same a on and classifies its various manifestations in a characteristic and year Weigert published paper a formed and exceedingly lucid exposition of different concrete glycerin as method of distinguishing unformed examples. ferments. The section is three No one can read such a broad and logical treatment of a com- bactériologie completed by to of recurrent fever. plex subject without a refreshing sense of renewed inspiration. papers relating Obermeyer's spirillae The section with and microteehnic consti- The pathology of tuberculosis is discussed in thirteen ar- dealing neurology of em- the first in before the demonstration tutes one of the most important portions the volume, ticles, appearing 1877, and of the tubercle bacillus, and the last published in 1903. These bodying, as it does, Weigert's extremely important funda- the of This sec- studies, therefore, embrace the most interesting epoch in the mental methods for differentiation tissues. tion contains the a on micro- development of knowledge concerning this disease and even following papers: First, paper technic which deals with the of section in those articles which now have chiefly an historical interest scopic subject cutting, certain in the microtome introduced one can not but admire the acute and observation improvements by Weigert thorough and the and of This and the close and suggestive deductions of the writer. There coloration impregnation preparations. in 1894. It is followed one are also several valuable papers on tumors, malformations, etc. paper was published by dealing with the technic of the central nervous One of the to which devoted much histologie system, pub- subjects Weigert produc- lished in 1896. This constitutes an admirable historical re- is tive study that of coagulation, both in the blood and tis- view of the and contains much of interest to histolo- and in subject sues, these volumes will be found his successive papers gists of the present day. It discusses the method of Golgi at elaborating the conception of coagulation necrosis and the and in a critical manner. The second contribu- which great length technic with the presence of fibrin and similar sub- tion to the histologie technic of the central nervous system ii stances may be demonstrated by a differential stain. These dated 1897 and deals in an exhaustive manner with the sub- articles afford another example of his patient effort to dis- ject of staining the medullary sheath of a nerve fiber and cover and define the essential facts and processes underlying with the principles concerned in such staining. The third of

Downloaded From: http://jama.jamanetwork.com/ by a Oakland University User on 06/08/2015 this series of contributions on the histologie technic of the these facts, relying probably on the presumed skill of central nervous system is likewise dated 1897 and is devoted the manufacturers and believing that nothing so worth- to the Marchi method. Then follow two papers dealing with less would be offered to them. In view of this misplaced the methods of staining fibrin. The first is dated 1887, giving to method of coloration of confidence, the Council has thought it advisable bring Weigert's original selective by means the facts to anilin dyes. The difference between this method and that of general attention. Gram is out. is very clearly brought This subject brought up MIXTURES OF FERMENTS IN LIQUID FORM. to date in a paper dated 1903, dealing again with the fibrin on stain. These papers are followed by one dated 1898 giving Digestion, in the human organism, is carried large- Weigert's method of staining elastic fibers. ly by the action of peculiar principles, ferments, secreted A section now follows which is devoted mainly to the papers by the glands connected with the alimentary canal. of Weigert in which are presented his discoveries of methods of These ferments are very powerful, in that they can staining the medullary sheaths of the central nervous system. effect profound changes in the foodstuffs, changes which In 1890 Weigert brought out his extremely important method which would of the the chemist can only imitate by processes staining neuroglia structures of the central nervous sys- be destructive to the human On the other tem in man. His two papers dealing with this discovery are organism. hand—and this is ferments are printed in this volume and are followed by a long contribu- very important—organic can exercise their actions tion, of the utmost significance to histology, in which the nor- very delicate bodies, which only mal human neuroglia is discussed from the historical stand- under favorable conditions, and which are either inhib- point and in the light of his own methods. This paper is dated ited or destroyed by very slight departures from these. 1895. Weigert's last contribution to the technic of the neu- They are quite as sensitive to reagents as proteids or roglia stain was made in 1903, in which he treats of ways of toxins, and reagents which injure the one are very apt improving his own, previously described, methods and also dis- to injure the others. Pepsin and pancreatin are used cusses similar methods for the study of neuroglia which have of and are been others. The rest the for the very purpose digesting proteids, they developed by of volume is given up also destructive to toxins it be rather to papers of less importance. It should be mentioned, however, ; would, therefore, not act on one in that among the papers which have been collected at the end strange if they did another, resulting alkalies are also of the volume is an extremely appreciative necrolog relating mutual destruction. Strong acids and In solutions to Weigert's master, Julius Cohnheim. This paper was writ- most injurious to ferments. very dilute ten in 1884. In the same year also was published a short dis- they are favorable to some, unfavorable to others. Pep- cussion on the subject of mind-reading. The last contribution sin and are opposite in this respect, and a re- deals with the of the of for pancreatin question establishment an institute action suited to the one will destroy the other. serum investigation and experimental therapy in Frankfurt These facts have been known in a way, a-M., and will be read with interest by those who have fol- long general and are confirmed in the most recent authori- lowed the classical contributions that have come from this they fully on the institute under the guidance of Ehrlich in the past nine years. tative work1 subject. The first the fer- It was as a and resourceful tech- investigators proceeded by mixing morphologist microscopic them at nician that Weigert entered and left his on the field ments and reagents and keeping body tempera- impress the of bacteriology, and his services to neurology are of similar ture, generally for six hours. After this exposure, character. In fact, throughout his writings we find that the quantity of ferment which had escaped destruction was chief data underlying his work were morphologic. But he was estimated by bringing the mixture to the reaction most pre-eminent in his ability to handle and verify these data. favorable to this ferment and adding fibrin, egg albumin They inspired him to seek the significance of the changes in solution, starch, etc., according to the nature of the structure he was so capable of detecting, and this striving led ferments. him ro his of vital and conception phenomena. The chemical The brief citations illustrate the nature of physical aspects of pathology are but lightly touched on, and following when considered at all are discussed mainly in reviews of the the results : work of others. That Weigert was in sympathy with these EXPERIMENTS ON TRYPSIN (PANCREATIN). more recent aspects of pathology can not oe doubted, but he (a) Effect of Hydrochloric Acid: was too completely engrossed in the on which he was problem In these the was submit- best fitted to work, to make notable contributions in these di- experiments trypsin (pancreatin) ted to the action of hydrochloric acid of varying strengths for rections. His publications in the field of his choice are des- a six hours. Then the was rendered alkaline, tined to become classics. period of liquid and now the time determined which was required to digest a certain amount of fibrin. After making alkaline the di- Per cent, of HC1 in the prelim- gestion of fibrin Is practically SOME FACTS ABOUT DIGESTIVE FERMENTS. inary digestion of six hours. completed in. 0.000 .3 hours. TORALD M.D. 0.056 .5 hours. SOLLMANN, 7 Professor of Pharmacology and Materia Medica, Western Reserve 0.112 . hours. 0.280 .8 hours. University; Member of the Council on Pharmacy and 0.560.No in 8 hours. Chemistry, American Medical Association. digestion normal CLEVELAND, OHIO. When it is remembered that the acidity of gastric juice generally corresponds to about 0.2 per cent. HC1 it will INTRODUCTION. be seen that an acidity of one-fourth of this figure weakens The Council on Pharmacy and Chemistry, in the the activity of the trypsin so that it requires about double the time to effect while to an but course of its work, found occasion to examine a number digestion; exposure acidity little above that of the gastric juice destroys it altogether. of articles widely advertised as digestants. A large pro- portion of these failed to come up to the claims which (6) Effect of Pepsin: were made for them\p=m-\afailure which have been Composition of the mixture for might the preliminary digestion of After making alkaline, the dl- predicted, since these claims often involve impossibilities slx hours. gestion of fibrin Is : as absurd as that of for the simultaneous action Trypsin and water.Practically completed In 3 hours. hoping Trypsin and 0.112 per cent. HC1. Starts In 5 hours; one-half Is di- of an acid and alkali the in other gested In 6 hours. by mixing two; words, Trypsin and 0.112 per cent. HC1 they are examples of well-established incompatabilities. and pepsin .No digestion in 29 hours. For the reason, however, that these preparations are ad- vertised indicates 1. Wroblewski, Bednarski and Wojczinski: Hofmeister's Beitr., that many physicians are overlooking 1901, I, 289.

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