450 
CONGRESS ON TUBERCULOSIS. 
and of these few cases that have been enumerated, it is by no 
means certain that they were due to Infection by bovine tuber¬ 
culosis. It is just as likely that they were caused by the widely 
propagated bacilli of human tuberculosis, which may have got 
into the digestive canal in some way or other—for instance, by 
swallowing saliva of the mouth. Hitherto nobody could decide 
with certainty in such a case whether the tuberculosis of the in¬ 
testine was of human or of animal origin. Now we can diag¬ 
nose them. All that is necessary is to cultivate in pure culture 
the tubercle-bacilli found in the tubercular material, and to as¬ 
certain whether they belong to bovine tuberculosis by inoculat¬ 
ing cattle with them. For this purpose I recommend subcutan¬ 
eous injection, which yields quite specially characteristic and 
convincing results. For half a year past I have occupied my¬ 
self with such investigations, but, owing to the rareness of the 
disease in question, the number of the cases I have been able to 
investigate is but small. What has hitherto resulted from this 
investigation does not speak for the assumption that bovine tu¬ 
berculosis occurs in man. 
Though the important question whether man is susceptible to 
bovine tuberculosis at all is not yet absolutely decided, and will 
not admit of absolute decision to-day or to-morrow, one is never¬ 
theless already at liberty to say that, if such a susceptibility really 
exists,the infection of human beings is but a very rare occurrence. 
I should estimate the extent of infection by the milk and flesh 
of tubercular cattle, and the butter made of their milk, as hardly 
greater than that of hereditary transmission, and I therefore do 
not deem it advisable to take any measures against it. 
So the only main source of the Infection of tuberculosis is 
the sputum of consumptive patients, and the measures for the 
combating of tuberculosis must aim at the prevention of the 
dangers arising from its diffusion. Well, what is to be done in 
this direction? Several ways are open. One’s first thought 
might be to consign all persons suffering from tuberculosis of 
the lungs, whose sputum contains tubercle-bacilli to suitable es¬ 
tablishments. This, however, is not only absolutely impracti¬ 
cable, but also unnecessary. For a consumptive who coughs 
out tubercle-bacilli is not necessarily a source of Infection on 
that account, so long as he takes care that his sputum is prop¬ 
erly removed and rendered innocuous. This is certainly true 
of very many patieuts, especially in the first stages, and also of 
those who belong to the well-to-do classes, and are able to pro¬ 
cure the necessary nursing. But how is it with people of very 
