JoiY ], 1904.] 



SCIENCE. 



the news brought in the journals or just as 

 often in the letters from Paris, or London 

 or even from little Weimar, where the 

 Wahlverwandtsehaften reflected the curi- 

 osity and enthusiasm of the epoch. There 

 was for a moment danger that the medical- 

 chemical history of the seventeenth century 

 would repeat itself at the beginning of the 

 nineteenth, when oxygen and the galvanic 

 cell began to be hailed in some quarters as 

 offering the key for all mysteries and the 

 cure for all diseases. But the three hun- 

 dred years following the rise of Paracelsus 

 had produced a new race of thinkers, and 

 only temporarily could men be brought 

 away from a now well-developed and neces- 

 sary tendency — the collection and investi- 

 gation of facts. 



It is not my purpose to sketch the fruit- 

 ful work of the next half century, as I wish 

 to speak particularly of a later period, but 

 it must be recalled that the pioneer labors 

 of Dumas, Liebig and Wohler in organic 

 chemistry made possible the later develop- 

 ments in physiological and pathological 

 chemistry. In this period of great scien- 

 tific activity it must be admitted, however, 

 that the practical influence of chemistry 

 on medicine was not very great. Each dis- 

 cipline developed largely in its own way, 

 and while the practitioner recognized in 

 physiology and physiological chemistry 

 sciences of great interest and beauty, he 

 was not very clear as to what uses he could 

 make of them except in a few limited di- 

 rections. Chemistry had become complete- 

 ly divorced from pharmacy and cared noth- 

 ing for the preparation of remedies, and 

 the applications of chemical analysis which 

 might prove an aid in diagnosis were as 

 yet few and far between. In the eyes of 

 the medical practitioner and medical stu- 

 dent chemistry was very theoretical, to be 

 tolerated rather tham to be cultivated. I 

 have elsewhere called attention to the al- 

 most futile efforts to build up courses in 



chemistry in the early medical schools of 

 the United States. The efforts failed here 

 as, practically speaking, they failed else- 

 where at the same time because of the lack 

 of immediate relationship of the one sci- 

 ence to the other. A medical man might 

 just as well be asked to study botany or 

 zoology as chemistry, as far as any really 

 helpful practical application was con- 

 cerned, excepting, perhaps, in two or three 

 simple tests. 



And so the situation remained until 

 about 1860, when the views of Pasteur on 

 alcoholic fermentation and the isolation by 

 the German physiologists of several active 

 soluble ferments or enzymes of the animal 

 body began to attract wide attention and 

 point the way toward an explanation of 

 many processes taking place in the organ- 

 ism. With the growing recognition of the 

 character and importance of the work of 

 the enzymes I think we have the first real 

 tangible evidence of the dependence of 

 medicine on the new chemistry. The doc- 

 trine of the ferments as applied to the 

 chemical changes taking place within the 

 body is one, apparently, of indefinite ex- 

 tension, and at the present day, after forty 

 years of trial, it seems more than ever 

 likely to hold its own and be capable of 

 even wider development. In passing, I 

 must add that it would not be fair to claim 

 that the great advances just suggested were 

 all due to the efforts of chemists. On the 

 contrary, many of them were conceived and 

 largely worked out by men who had been 

 trained primarily in medicine rather than 

 in chemistry. 



In speaking of the relations of modern 

 medicine and chemistry it may be recog- 

 nized that they are essentially of three 

 kinds. We have first the very simple and 

 so-called practical relation in which chem- 

 istry becomes an aid to medicine in the way 

 of diagnosis. Here analytical chemistry is 

 alone concerned and the chemist is called 



