226 TUBERCULOSIS. 



were, however, successfully overcome. lie cultivated the organism by 

 the above method from a great variety of sources, and by a large series 

 of inoculation experiments on various animals, performed by different 

 methods, he conclusively proved that bacilli from these different 

 sources produced the same tubercular lesions and were really of the 

 same species. His work was the means of showing conclusively that 

 such conditions as lupus, " white swelling" of joints, scrofulous disease 

 of glands, etc., are really tubercular in nature. 



Tuberculosis in Animals. Tuberculosis is not only the 

 most widely spread of all diseases affecting the human 

 subject, and produces a mortality greater than any other, 

 but there is probably no other disease which affects the 

 domestic animals so widely. We need not here describe in 

 detail the various tubercular lesions in the human subject, 

 but some facts regarding the disease in the lower animals 

 may be given, as this subject is of great importance in rela- 

 tion to the infection of the human subject. 



Amongst the domestic animals the disease is com- 

 monest in cattle (bovine tuberculosis), and in them the 

 lesions are very various, both in their character and dis- 

 tribution. In most cases the lungs are affected, and 

 contain numerous rounded nodules, many being of con- 

 siderable size ; these may be softened in the centre, 

 but are usually of pretty firm consistence and may 

 be calcified. There may be in addition caseous pneu- 

 monia, and also small tubercular granulations. Along 

 with these changes in the lungs, the pleurae are also often 

 affected, and show numerous nodules, some of which may 

 be of large size, firm and pedunculated, the condition being 

 known in Germany as Perlsucht, in France as powmeliere. 

 Lesions similar to the last may be chiefly confined to the 

 peritoneum and pleurae. In other cases, again, the abdo- 

 minal organs are principally involved. The udder becomes 

 affected in a certain proportion of cases of tuberculosis in 

 cows in 3 per cent according to Bang but primary affec- 

 tion of this gland is very rare. Tuberculosis is also a com- 

 paratively common disease in pigs, in which animals it in 

 many cases affects the abdominal organs, in other cases 

 produces a sort of caseous pneumonia, and sometimes 



