TUBERCULOSIS. 
687 
experiments conducted with this substance a marked elevation 
of temperature was noticed when it was injected into the system 
of tuberculous subjects. - In healthy subjects no elevation of 
temperature was noticed. In view of this fact tuberculin has 
been extensively used since 1891 as a diagnostic agent in the 
ower animals. For this purpose its value cannot be over 
estimated. The manner in which it acts as a diagnostic agent 
is an interesting one and demands a few moments of our 
time. 
. * haVe stated before that the system of tuberculous patients 
is charged with the toxalbumins of the germ of the disease. 
This product of the germ is nothing more nor less than tuber¬ 
culin. The addition of a small amount of artificially prepared 
tuberculin to that already contained in the system causes a tem¬ 
porary fever, or reaction, in from six to twelve hours after the 
injection. The reaction varies from one to six degrees above 
the average normal temperature, and lasts from twelve to four¬ 
teen hours. In healthy subjects the quantity of tuberculin in¬ 
jected is so small that the animal is not affected by it. Reports 
are unanimous in support of this statement. 
That this new method of detecting the disease in all of its 
stages is an extremely delicate and accurate one will be seen by 
the following experiments : 
In April, 1893, tuberculin was used on the entire herd of 
cattle at the Experiment Station, with the result that only one 
animal gave the reaction. This animal was a thoroughbred 
Shorthorn cow in excellent flesh for beef, for which she would 
have been sold in another week, as she was worthless as a dairy 
cow. The elevation of temperature above the normal was i.8°. 
A post-mortem examination revealed intestinal tuberculosis, 
with two large tubercles on the liver. In July, of the same year ’ 
by the request of Captain C. E. Vawter, of the Miller School’ 
and with the assistance of Prof. Tinsley, I used tuberculin on 
the entire herd of milch cows belonging to the above mentioned 
school with the result that one cow gave a reaction of 4.2 0 . An 
autopsy in this case revealed intestinal and pulmonary tubercu- 
