Tuberculosis. 409 



extensive and intensive lesions, rabbits much less so, but in both 

 emaciation and wasting are very marked. In short the lesions 

 are essentially and unmistakably those of generalized tuber- 

 culosis. 



" At first, however, incredulity prevailed and experiments on a 

 large scale were inaugurated all over Europe and America to put 

 the question to crucial test. Martin, Conheim, Burdon-Sander- 

 son, Simon, Wilson, Fox, L,ebert and Wyss, Fraenkel, Walden- 

 bourg, and others inoculated with all sorts of non-tuberculous 

 organic materials (bronchial mucus, foul pus, cancer juice, dis- 

 eased liver, simple cotton setons, etc.) and from these in Guinea 

 pigs there resulted local caseated foci, and implication of the 

 adjacent lymphatic glands. It was found that the liquids from 

 low types of pneumonia produced these apparently tubercular 

 deposits, while that from acute sthenic pneumonia did not ; thut 

 the cotton thread seton failed to produce the disease if it were 

 first steeped in carbolic acid, and that the lesion caused by break- 

 ing a bone without injury to the skin failed to produce the 

 characteristic lesions even in the very susceptible Guinea pig. 

 It became evident, therefore, that the morbid results in these 

 cases, were due to accidental inoculations with the poison of the 

 tubercle, which is widely distributed, or with some pyaemic or 

 other germs. 



" Gradually the truth triumphed, and those who had at first 

 been loudest in their opposition were led by their own experi- 

 ments to become the firmest supporters of the new truth. 



" As early as 1874, Gerlach had experimented largely in feed- 

 ing the milk of tuberculous cows, and had infected calves, pigs, 

 sheep and rabbits in this way. Chauveau in (1874), Klebs (1873), 

 Semmer (1880) and Parrot (1870) fed calves, cats, Guinea pigs, 

 pigs, sheep and a variety of other species of animals with tuber- 

 culous flesh or lungs, or saliva, producing tuberculosis in a large 

 proportion of cases. In this manner they escaped the charge of 

 the operation of a wound and of aerial bacteria, and yet succeeded 

 in producing infection. The lesions in this case began in the in- 

 testinal mucous membranes and mesenteric glands. 



" Another essay in the same direction was made by Tappeiner 

 (1878), who infected rabbits, Guinea-pigs and dogs, by enclosing 

 them in boxes and compelling them to breathe tuberculous 



