112 



TUBERCLE 



whose conditions of life are for the most part 

 already known, and can be further studied. . . . 

 Before all things, we must shut off the sources of 

 the infection, so far as it is in the power of man to 

 do this."* 



In November 1890 he announced, in the 

 Deutsche Medizinische Woe hens chrift, the discovery 

 of tuberculin. Its failure was one of the world's 

 tragedies ; and, for all the years of careful work 

 that have been given to its improvement, from 1890 

 until now, it still, in the general opinion of medical 

 men, fails to fulfil the hope that it first inspired. 

 The modified forms of it have given, here or there, 

 good results : the defeat may not be final, and men 

 may live to see phthisis fought and beaten with its 

 own weapons : but, for the present, it is more to the 

 purpose to consider what other benefits have been 

 gained, from the discovery of the tubercle-bacillus 

 in 1882, in every civilised country in the world. 



1. It has given to everybody a more reasonable 

 and hopeful view of phthisis and the diseases allied 

 to it. The older doctrine of heredity, that the child 

 inherits the disease itself, has given way to the 

 doctrine that the inheritance, in the vast majority of 



* " In Zukunft wird man es im Kampf gegen diese schreck- 

 liche Plage des Menschengeschlechtes nicht mehr mit einem 

 unbestimmten Etwas, sondern mit einem fassbaren Parasiten 

 zu thim haben, dessen Lebensbedingungen zum grossten Theil 

 bekannt sind und noch weiter erforscht werden. Es miissen 

 vor alien Dingen die Quellen, aus denen der Infections-stoff 

 fliesst, so weit es in menschlichen Macht liegt, verschlossen 

 werden." 



