RESEARCH IN MEDICINE 131 



methods of a science of clinical medicine and have aided materially in 

 the advance of this branch of medicine. 



Such are the methods and problems of present-day research in medi- 

 cine. The history of medicine teaches us that new methods and fruit- 

 ful hypotheses may be brought forth at any time ; new diseases, on the 

 other hand, can now be expected only through changes in social rela- 

 tions and practises or as the result of new industries. Advance, there- 

 fore, would appear to lie in the concentrated application of present 

 methods to present problems and in the application of such new meth- 

 ods, as may be confidently expected to appear from time to time, in 

 any science which is so actively cultivated as is the science of modern 

 medicine. 



In this narrative of research medicine I have grouped the various 

 phases of my presentation about men or events. These, as Hippocrates 

 and Galen in antiquity; Vesalius and his influence on anatomy; Pare 

 and his observations in surgery; Harvey, Hunter and Haller and their 

 more or less isolated discoveries in physiology; Morgagni and his ob- 

 servations in pathological anatomy; and Jenner and his discovery of 

 vaccination, represent the epoch-making efforts of workers widely sepa- 

 rated and more or less isolated. In the early part of the nineteenth 

 century, Johannes Miiller, Liebig and Rokitansky founded respectively 

 the sciences of physiology, organic chemistry and pathological anat- 

 omy upon the basis of concentrated laboratory effort and gave to these 

 sciences an impetus the result of which we recognize to-day in the im- 

 portance which they have attained. The main line of advance, how- 

 ever, has been in the past 70 years, and was made possible by the study 

 of cells, through (1) the work of Schleiden on vegetable cells and of 

 Schwann on animal cells thus establishing the cell doctrine; (2) the 

 application of this theory by Virchow to pathology, and (3) Pasteur's 

 conception of the role played by microscopic cells in fermentation and 

 his application of this to the etiology of disease. Out of Pasteur's work 

 grew, the treatment of bacterial diseases by vaccines and antitoxic sera, 

 and the increased knowledge of infectious diseases gained by the study 

 of bacteriology, led to the search for protozoa as causes of disease and 

 the demonstration of the etiological importance of the latter, led, in 

 turn, to the development of Ehrlich's chemotherapy as a means of com- 

 bating protozoan disease. But while this was the main line of advance 

 we have seen how Pasteur influenced surgery through Lister, and how 

 anesthesia, through the efforts of Morton came also to aid this science. 

 So, likewise, physiological chemistry came into being, indirectly as a re- 

 sult of Liebig's work, but more directly as a result of the needs of 

 physiology for a better understanding of cell composition and enzyme 

 action, and, finally, both physiology and physiological chemistry con- 



