TUBERCULIN TESTS OE THE COLLEGE HERD. 
19 
reason for condemning it as a diagnostic agent. It is be¬ 
lieved that it does not fail to detect the disease in more than 
one-fifth of one per cent, of cases which are not far advanced 
in their course, and in our experience the disease has been 
found in every case which responded to the test. 
Tuberculin is a glycerine extract of the toxin produced 
by the bacillus tuberculosis, but it contains no living germs 
which can communicate the disease. The normal tempera¬ 
ture of an animal is obtained, then a small quantity of the 
tuberculin is injected hypodermically so it will be absorbed 
into the blood. If the animal is diseased the tuberculin 
causes a rise in temperature of 2 degrees or more in 8 to 16 
hours, and sometimes a swelling and soreness where the in¬ 
jection was made. It should be used under the direction of 
a veterinarian or physician, or someone who has used and 
understands the method of applying the tuberculin and ob¬ 
serving the results. 
WHY WE TESTED THE COLLEGE HERD. 
Our cattle had not been tested and we suspected the 
disease. However, we had only one animal under suspi¬ 
cion, and we hoped she would be the only case. Gildana, a 
Jersey cow about eight years old had been out of health for 
some months. She had the malignant catarrhal fever which 
was prevalent during the fall months, and did not recover 
as did other animals which were affected. She seemed to 
be passing into decrepid old age which we thought due in 
all probability to tuberculosis. Dr. Glover was consulted 
and he agreed to test the dairy herd. We did not expect to 
find many cases as we thought there was reason to believe 
that tuberculosis might not be so prevalent in our dry sunny 
climate as it had proved to be in more humid regions. 
There may have been a little personal pride in the thought 
that our cattle, which had been given the best of care under 
the most favorable conditions, would be unusually healthy. 
As we will show later this idea was not without some found¬ 
ation in fact. But tuberculosis is a disease which leaves its 
victim hopeful and in good cheer and one about which the 
novice should not jump at conclusions. We guessed that 
Gildana had tuberculosis, but we guessed wrong, for she did* 
not respond to the test and is now believed to be healthy, 
while other cows in the herd which to all appearances were 
healthy, were found to be veritable pest houses of infection. 
Again, because cattle form so large a part of human 
food; because they are subject to many diseases fatal to 
