TUBERCULOSIS 



165 



ing the thermometer in the rectum and allowing 

 it to remain there for three or four minutes 

 before reading. About half a teaspoonful (2 c.c.) 

 of the tuberculin is then injected underneath the 



Fig. 45. This picture shows how tuberculin is injected under 

 the skin in making the tuberculin test. 



skin, usually at the shoulder, with an ordinary 

 hypodermic syringe. Eight to ten hours after 

 injection five more temperatures are taken in 

 the same manner, two hours apart. A rise in 

 temperature of two degrees is considered a "pos- 

 itive reaction;" that is, the animal is said to be 

 diseased. 



