560 
CORRESPONDENCE. 
Department of Parke, Davis & Co., Detroit, Mich., I was 
requested to test the efficiency of certain samples of tuberculin. 
In carrying out the test a yearling heifer in good condition was 
selected, and to insure accuracy it was tuberculin tested, but did 
not react. 
In the course of a few days I was given some human sputum, 
which I was informed was very rich in the germs of tubercu¬ 
losis, and that it had been obtained from a virulent case in a 
man. I placed about a teaspoonful of this material beneath the 
skin of the heifer, just behind the shoulder blade, put the ani¬ 
mal^ into comfortable quarters and awaited results. In the 
course of two or three weeks the animal began to fail and the 
appetite became capricious; in about six weeks I concluded it 
was a genuine case of tuberculosis, and that it would be a good 
time to test the efficiency of the tuberculin ; the test was accord- 
ingly applied and the animal reacted in a most marked manner, 
indicating tuberculosis. A post-mortem w T as then held, but the 
general tuberculosis of the mesenteric glands and lungs which I 
expected to find was not present. I did, however, find a lym¬ 
phatic gland in proximity to the point of inoculation which 
presented every appearance of tuberculosis, and microscopic 
examination verified the diagnosis first made. Having appar¬ 
ently produced tuberculosis in the animal which afterwards 
responded to the test, and thus established the efficiency of the 
sample of tuberculin, I seemed to have accomplished my test. 
The only difference which I can see between this experiment 
and some of those conducted by Prof. Koch, was that the sputum 
which I used had been examined microscopically before injec¬ 
tion and the animal was tuberculin tested before the autopsy 
was made. 
With regard to some of the other experiments of Prof. Koch 
in testing the virulence of human and bovine tuberculosis they 
do not seem to be parallel. To wit: In the effort to transmit 
human tuberculosis to the bovine, in some cases sputum was 
used which must have been contaminated ; in others artificial 
cultures were used, which may or may not have been atten¬ 
uated, while in transmitting tuberculosis from bovine to bovine 
the lung substance of a tubercular animal was used. In any 
work that I have conducted in this line the most pronounced 
effects have always been produced when the lung substance of 
a recently killed tubercular animal has been used for injection 
or feeding purposes. 
Considering all that has been done in the past by way of 
