RESEARCH IN MEDICINE 115 



RESEARCH IN MEDICINE 1 



By Professor RICHARD M. PEARCE 



UNIVERSITY OP PENNSYLVANIA 



IV. Present-day Methods and Problems 



THE important activities in scientific medicine at the present time 

 may be said, without fear of contradiction, to be in. the depart- 

 ments of (1) immunology, 2 (2) protozoology, (3) chemotherapy, (4) 

 physiological chemistry, (5) experimental pharmacology and (6) 

 experimental pathology. The methods and problems of these various 

 phases of medicine it is my intention to discuss, some at length, others 

 briefly, in the present lecture. 



Immunology is the science which would explain and apply the 

 mechanisms by means of which the animal body is enabled to resist 

 disease. As has been shown, the efforts of bacteriologists until about 

 1890 were devoted almost entirely to the study of the etiology of the 

 infectious diseases and to attempts to combat these by vaccination with 

 attenuated viruses. Another phase of bacteriology was, however, 

 already under way, and this, in the earlier nineties, not only yielded 

 results of great practical importance, but opened a new and ever-widen- 

 ing field of investigation. This was the study of the mode of action 

 of invading bacteria and their products, that is, of the process of infec- 

 tion and intoxication, and the mechanism by which the host combats 

 the invasion and absorbs or cures such infection by overwhelming the 

 foreign organism. One of the first results was the study of a group of 

 soluble poisons, toxins — formed by certain bacteria and which it has 

 been found are responsible not only for the symptoms which follow 

 certain infections, but also for that effect on the cells of the host which 

 stimulates the formation of the antibodies which we call antitoxins. 

 Pasteur in his study of chicken-cholera had noticed that a bacteria-free 

 filtrate of a culture of the specific microorganism of this disease could 

 cause the symptoms produced by the bacilli themselves, but does not 

 seem to have given much importance to the observation. Later (1888) 

 two of his assistants, Roux and Yersin, found the same to be true of 

 filtered cultures of the diphtheria bacillus. Later it was found that the 

 tetanus bacillus and the bacillus (B. botulismus) of meat poisoning 

 yielded similar soluble poisons. 



1 The Hitchcock lectures, delivered at the University of California, January 

 23-26, 1912. 



2 The use of this term is not perhaps above criticism, but its increasing use 

 and need of some comprehensive word to cover the various activities represented 

 by the term ' ' studies in immunity, " " serology ' ' which in themselves are not 

 adequate, are given as justification of its use. 



