NINTH ANNUAL YEAR BOOK— PART X 475 
injection had produced in no single case an unusually rapid or vicious 
course of tuberculosis. In spite of a demand made monttis ago, I have 
received thus far no report from any veterinarian of an undesirable 
result. 
On a large farm, on which before the injection tuberculosis had ap- 
peared in a vicious form the owner had the impression that the severe 
cases had afterwards become more numerous. He had, however, not 
suffered severe losses, and eight months later the large reacting division 
by no means made a bad impression. Finally, it is to be noticed that 
tuberculin has been employed on a large scale in Denmark for years, and 
still the demand from farmers constantly increases. This could certainly 
not be the case if the injections were generally followed by bad results. 
Paige said, after the tests of the herd of the Massachusetts Agricul- 
tural College, tliat "its use is not followed by any ill effects of a serious 
or permanent nature.' " 
Lamson of the New Hampshire College Agricultural Experiment Sta- 
tion, said: "There is abundant testimony that its use is not in any way 
injurious to a healthy animal." 
Conn, who made a special study of the present attitude of European 
science toward tuberculosis in cattle, reached the following conclusions: 
It has been, from the first, thought by some that the use of tuberculin 
produces a direct injury upon the inoculated animals. This, however, is 
undoubtedly a mistake, and there is no longer any belief anyvvhere on 
the part of scientists that the injury thus produced is worthy of note. 
In the first place, the idea that it may produce the disease in a perfectly 
healthy animal by the inoculation is absolutely fallacious. The tuberculin 
does not corttain the tubercle bacillus, and it is absolutely certain that it 
is impossible to produce a case of tuberculosis in an animal unless the 
tubercle bacilli are present. The use of tuberculin, therefore, certainly 
can never produce the disease in the inoculated animal. 
It has been more widely believed, however, that the inoculation of an 
animal v/ith this material has a tendency to stimulate an incipient case 
of tuberculosis. It has been thought that an animal with a very slight 
case of the disease may, after inoculation, show a very rapid extension 
of this disease and be speedily brought to a condition where it is beyond 
any use. The reasons given for this have been the apparent activity of 
the tuberculosis infection in animals that have been slaughtered shortly 
after inoculation. This has been claimed, not only by agriculturists who 
have not understood the subject well, but also by veterinarians and bac- 
teriologists. But here, too, we must recognize that the claim has been 
disproved and that there is now a practical unanimity of opinion on the 
part of all who are best calculated to judge, that such an injurious effect 
does not occur. Even those who have been most pronounced in the claim 
that there is injury thus resulting from tuberculin have, little by little, 
modified their claim, until at the present time they say either that the in- 
jury w^hich they formerly claimed does not occur, or that the stimulus of the 
two or three who hold this very moderate opinion, all bacteriologists 
and vptprlnarians iinifp in np-rppin^ that thprp is no pvidpnpp fnr hplievina: 
