448 
CONGRESS ON TUBERCULOSIS. 
ment with swine. Six young swine were fed daily for three 
months with the tubercular sputum* of consumptive patients. 
Six other swine received bacilli of bovine tuberculosis with 
their food daily for the same period. The animals 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 months and a half 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 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 tuberculosis 
had, without exception (just as in the cattle experiment), severe 
tubercular diseases, especially tubercular infiltration of the 
greatly enlarged lymphatic glands of the neck and of the mes- 
sentric glands, and also extensive tuberculosis of the lungs and 
the spleen. 
The difference between human and bovine tuberculosis ap¬ 
peared not less strikingly in a similar experiment with asses, 
sheep, and 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 experi¬ 
ments that were made in former times by Chauveau, Gunther 
and Harms, Bollinger, and others, who fed calves, swine, and 
goats with tubercular material, one finds 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. Comparative investi¬ 
gations regarding human and bovine tuberculosis have been 
made very recently in North America by Smith, Dinwiddie 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 every¬ 
thing connected with the stalling, feeding, and tending of the 
animals that might have a disturbing effect on the experi¬ 
ments. 
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, 
