112 PATHOLOGY 



Fortunately Clark's warning had been anticipated by development. 

 Virchow himself long before repeatedly emphasized that pathologi- 

 cal anatomy cannot deal forever with the product without searching 

 for the cause that led to its production. It seems to me that the 

 following highly remarkable statement in the Prospectus of the first 

 volume of Virchow's Archiv, published in 1847, shows that the 

 founder of cellular pathology had a wonderfully clear vision of the 

 role pathological anatomy was to play in the evolution of patholog- 

 ical physiology: 



"The standpoint we aim to occupy is simply that of natural sci- 

 ence. Practical medicine, the applied theoretical, the theoretical- 

 pathological physiology is the ideal we shall strive to reach so far 

 as our powers permit. While we recognize fully the title and the 

 independence of pathological anatomy, and of the clinic, they serve 

 us preeminently as sources of new questions the answers to which 

 fall to the lot of pathological physiology. Inasmuch, however, as 

 these questions to a large extent may be formulated only through 

 painstaking and comprehensive detailed study of manifestations 

 (of disease) in the living, and of the conditions in the dead, we regard 

 the exact growth of anatomical and clinical experiences as the first 

 and most important demand of the present time. From an empir- 

 icism of this kind will result gradually the true theory of medicine, 

 pathological physiology!" 



Microbiology, Etiology, Comparative Pathology 



It was reserved for etiology, the offspring of microbiology, "to 

 lift pathology permanently out of the level of a purely descriptive 

 science, for with the entrance of a dynamic factor, a causal element, 

 under the guise of microorganisms, the experimental era began 

 definitely." 



The coming of microbiology, long foreshadowed by ingenious 

 speculations concerning infectious diseases, at once made patho- 

 logy broader and definitely comparative in its scope, thus widening 

 its relations to general biology on the one hand, and to preventive 

 and curative medicine on the other. It. will be recalled that the 

 founders of bacteriology Pasteur, chemist and biologist, and 

 Koch, physician both made their appearance in medicine as inves- 

 tigators of animal infections. Infectious diseases constitute a promi- 

 nent part in the field of pathology, and deeper insight into their 

 nature required simple, easily controllable conditions accessible to 

 experiment and analysis. This became possible by the discovery 

 and study of microorganisms which could be used to set in motion 

 the complex phenomena of disease according to the pleasure of the 

 investigator. In animals the course of a disease may be cut short 



