30 MEDICINE 



scientific investigation. It is remarkable that the great awakening 

 in France which preceded it should have been characterized by the 

 opposite tendencies. During this period of speculation in Germany 

 valuable contributions to knowledge were continually being made 

 in anatomy and physiology. The chief exponents of the Natur- 

 philosophie were physicians who had to do with the clinical phe- 

 nomena of disease. Speculation was fostered because the methods 

 of gaining information from the study of disease were at the time 

 so meager that observation was restricted. So confirmed was the 

 habit of speculation that each new discovery in anatomy and physi- 

 ology, instead of serving as a basis for investigation, became food 

 for new speculation. 



It is possible to see the influence of the Natur-philosophie on its 

 greatest opponent, Rudolf Virchow. No one more clearly laid down 

 the methods of scientific investigation than did Virchow in the 

 opening articles of his Archivs. He was a born investigator and 

 made valuable contributions to knowledge in every department 

 of medicine. The protocols of his autopsies are models of full and 

 accurate descriptions of observations. He made important additions 

 to the technic and methods of work by the use of which new know- 

 ledge was gained. He was a great teacher as well as investigator, 

 and men trained in his methods are among the most famous in 

 medicine. 



It is difficult to find in the history of modern medicine any one 

 who can be compared with Virchow in the contributions made to 

 medical knowledge and the influence which he exerted. He sub- 

 stituted for the ontologic conception of disease, which was prevalent 

 in Germany at that time, the conception which we adopt to-day, 

 that it consists in life under altered conditions. This is not an 

 explanation, but a simple way of stating the summation of the 

 most obvious phenomena. He created the cell theory of disease, 

 which, though it represented an enormous advance over prevalent 

 theories and has been most stimulating to investigation, can no 

 more be held in its entirety as Virchow gave it than any of the 

 systems it supplanted. Unlike the other systems, it did not pretend 

 to be all-satisfying and all-explaining. The cell theory of disease 

 should be regarded as an hypothesis fully justified in being formed 

 from the knowledge at that time available. In Virchow's theory of 

 inflammation we see the great value of an hypothesis which, though 

 gradually proved incorrect by continued observations, has been 

 most stimulating to investigation. It is interesting to see the con- 

 tention which has been excited by theory. No one contends for the 

 acceptance of an observation, but is content to leave this for time, 

 but the contention is for the conception based on the observation 

 and the theory formed from the conceptions. Virchow properly 



