No. G. DEPARTMENT OF AGRICULTURE. 459 



growths which nic so (luiraetei-islic of hovlue tiibei'culosis were 

 iouiul ou (he onu'iilum and iieritoneum. lu short, (he cattle proved 

 just as susceptible to infection by the bacillus of bovine tuberculosis 

 as they had proved i^isiisceptible to infection by (he bacillus of 

 human tuberculosis. 1 wish only to add that preparations of the 

 organs of the catde which were ariilicially infec(ed with bovine tu- 

 berculosis iu these experiments are exhibited in the Museum of Path- 

 ology and Bacteriology. 



An almost equally striking distinction between human and bovine 

 tuberculosis was brought to light by a feeding experiment with 

 swine. iSix you«g swine were fed daily for three months with the 

 tubercular sputum of consumptive patients. Six other swine re- 

 ceived bacilli of bovine tuberculosis with their food daily for the 

 same period. The animals that were fed with spu(um remained 

 healthy and grew lustily, whereas those that were fed wi(h (he bacilli 

 of bovine tuberculosis soon became sickly, were stunted in their 

 growth, and half of them died. After (hree months and a half 

 the surviving swine were all killed and examined. Among the ani- 

 mals that liad been fed with sputum not a trace of tuberculosis was 

 found, except here and there little nodules in the lymphatic glands 

 of the neck, and in one case a few grey nodules in the lungs. The 

 animals, on the other hand, which had eaten bacilli of bovine tuber- 

 culosis had, without exception (just as in the cattle experiment), 

 severe tubercular diseases, especially tubercular inflltratioo of the 

 greatly enlarged lymphatic glands of the neck and of the mesenteric 

 glands, and also extensive tuberculosis of the lungs aud the spleen. 



The dilTerence between human and bovine tuberculosis appeared 

 not less strikingly in a similar experiment with asses, sheep aod 

 goats, into whose vascular systems the two kinds of tubercle-bacilli 

 were injected. 



Our experiments, I must add, are not the only ones that have led 

 to this result. If one studies the older literature of the subject, and 

 collates the reports of the numerous experiments that were made in 

 former times by Chauveau, Giinther, Harms, Bollinger, and others, 

 who fed calves, swine and goats with tubercular material, one 

 tinds that the animals that were fed with the milk and pieces of 

 the lungs of tubercular cattle always fell ill of tuberculosis, whereas 

 those that received human material with their food did not. Com- 

 parative investigations regarding human and bovine tuberculosis 

 have been made very recently in North America by Smith, Dinwid- 

 dle and Frothingham. and their result agreed with that of ours. 

 The unambiguous and absolutely conclusive result of our experi- 

 ments is due to the fact that we chose methods of infection which 

 exclude all sources of error, and carefully avoided everything con- 

 lu'eted with the stalling, feeding, and tending of the animals that 

 might have a disturbing effect on the experiments. 



