TUBERCULOSIS OF ANIMALS. 
65 
B. We are told that the virulency of the parts of a tuber¬ 
culous animal selected for alimentary uses is either quite 
wanting or very slight in degree when called to act in 
the connective tissue, and that it may be entirely ignored 
when its action is to take place in the intestines. This opti¬ 
mistic conclusion rests upon quite too compliant an interpre¬ 
tation of the experimental facts. The quickest and surest 
way of demonstrating the presence of the tuberculous virus 
in a suspected fluid or tissue is to employ it in the inoculation 
of the peritoneum of animals possessing a high degree of sus¬ 
ceptibility to the tuberculosis infection. The virulency of 
the blood and of the muscular juice has been demonstrated 
by this process in a great number of cases. But inasmuch as 
success has not been absolutely invariable, certain “ reason- 
ers,” taking advantage of the negative results, have claimed 
that tuberculous virus does not exist in microscopic lesions. 
And again, they willfully exaggerate the proportion of the 
negative results, and tacitly concede only an insignificant 
value to the demonstrated facts. 
We have with the most scrupulous care and impartiality 
collected reports of forty-seven experiments designed to as¬ 
certain the comparative degrees of virulency possessed by 
tuberculous animals free from muscular lesions. In all, one 
hundred and thirty-seven guinea pigs were used in these 
experiments. Out of these forty-seven recorded cases, nine 
have given us thirteen positive results.. Consequently, 
from the comparatively small statistical showing the flesh of 
tuberculous animals has proved itself infecting in one-fifth of 
the cases, and has tuberculized the inoculated subjects in the 
proportion of 9.4 per cent. We desire to remark emphati¬ 
cally that these figures are the minima. Indeed, it must not 
be forgotten that the virulent bacilli are irregularly dispersed 
through the muscular masses ; that only a very small fraction 
of them are used in the inoculation and again, that only the 
juice of the muscle is injected ; and moreover, that a number 
of microbes much greater than those extracted in the juice, 
must remain in the pulp of the tissue submitted to dilaceration,, 
or to the squeezing process. 
