TEE COMBATING OF TUBERCULOSIS. 467 



An almost equally striking distinction between human and bovine 

 tuberculosis was brought to light by a feeding experiment with swine. 

 Six young swine were fed daily for three months with the tuberculous 

 sputum of consumptive patients. Six other swine received bacilli of 

 bovine tuberculosis with their food daily for the same period. The ani- 

 mals that were fed with sputum remained healthy and grew lustily, 

 whereas those that were fed with the bacilli of bovine tuberculosis soon 

 became sickly, were stunted in their growth, and half of them died. 

 After three and a half months the surviving swine were all killed and 

 examined. Among the animals that had been fed with sputum no 

 trace of tuberculosis was found, except here and there little nodules 

 in the l}Tnphatic 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 tuberculosis had, without exception (just as in the cattle ex- 

 periment), severe tuberculous diseases, especially tuberculous infiltra- 

 tion of the greatly enlarged lymphatic glands of the neck and of the 

 mesenteric glands, and also extensive tuberculosis of the lungs and 

 the spleen. 



The difference betw^een human and bovine tuberculosis appeared 

 not less strikingly in a similar experiment with asses, sheep and goats, 

 into whose vascular systems the two kinds of tubercle bacilli were in- 

 jected. 



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 and Harms, Bollinger and others, 

 who fed calves, swdne and goats with tuberculous material, one finds 

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

 tuberculous cattle always fell ill of tuberculosis, whereas those that 

 were fed with human material did not. Comparative investigations 

 regarding human and bovine tuberculosis have been made very recently 

 in North America by Smith, Dinwiddle, Frothingham and Eepp, and 

 their result agreed with that of ours. The unambiguous and absolutely 

 conclusive result of our experiments is due to the fact that we chose 

 methods of infection which excluded all sources of error, and carefully 

 avoided everything connected with the stalling, feeding and tending 

 of the animals that might have a disturbing effect on the experiments. 

 Considering all these facts, I feel justified in maintaining that human 

 tuberculosis differs from bovine and cannot be transmitted to cattle. 

 It seems to me very desirable, however, that these experiments should 

 be repeated elsewhere, in order that all doubts as to the correctness of 

 my assertion may be removed. I wish only to add that, owing to the 

 great importance of this matter, our Government has resolved to ap- 

 point a commission to make further inquiries on the subject. 



