558 THE POPULAR SCIENCE MONTHLY 



pathological, and outlined a classification of new growths which is the 

 basis of all present-day knowledge of tumors. 



With his activities as anthropologist-archeologist we are not espe- 

 cially concerned except as they indicate the wide range of his interests. 

 He was one of the founders of the German Anthropological Society, 

 and later its president, and made expeditions with Schliemann to Troy, 

 Egypt, Nubia and the Peloponnese. 



Of vast importance to medicine, however, was his establislmient of 

 the first pathological laboratory, at the time he returned (in 1855) to 

 Berlin from Wiirzburg after a political exile of eight years; an exile 

 due to his sympathy with the revolutionary tendencies of 1848. This 

 laboratory was the forerunner of the many which have been founded in 

 the past fifty-five years in all parts of the world, and which have been 

 found essential not only for the purpose of teaching and research, but 

 also in the modern hospital. And again of importance is that influence 

 exerted through his famous pupils such as Leyden, v. Eecklinghausen, 

 Cohnheim, Waldeyer, Kiihne and Eindfleisch, to mention only the more 

 prominent, who carried his views to other fields and continued his 

 methods. Other great influences were to extend the territory of pathol- 

 ogy, as, for examples, Cohnheim's conception of experimental pathology, 

 Weigert's tinctorial methods for the difi'erentiation of cells and tissues, 

 Ehrlich's application of these methods to the study of the blood, 

 Metchnikoff's studies in comparative pathology, and finally the science 

 of bacteriology; but with Virchow remains the credit of having estab- 

 lished pathology as a science of university rank. 



The third of a century beginning in 1838 with the founding of 

 Liebig's laboratory and ending in 1858 with the publication of Vir- 

 chow's doctrine of cellular pathology, represents a greater advance in 

 the science of medicine than the combined activities of all the preceding 

 centuries. What was the influence of these advances on the art and 

 practise of medicine? Medicine at the beginning of the century was 

 still influenced by the metaphysical treatment of scientific subjects. 

 The previous century had been one of schools and systems, those of 

 Cullen and Brown in England, Broussais in France and Hoffman and 

 Stahl in Germany. It was also the time of Hahnemann (1753-1844) 

 and the rise of homeopathy. The prevailing tendency was to base dis- 

 ease on the study of symptoms, without regard to the underlying patho- 

 logical changes causing the symptoms. A few quotations may bring 

 this period of change from the old to the new prominently before you. 



Helmholtz writes of the period of his student life : 



My education fell ■within a period of the development of modern medicine 

 when among thinking and conscientious minds there reigned perfect despair. 

 It was not dif3Eicult to understand that the older and mostly theorizing methods 

 of treating medical subjects had become absolutely useless. . . . We can not 

 wonder if many honest, serious thinking men turned away in dissatisfaction 

 from medicine, or if they from principle embraced an extreme empiricism. 



