Tuberculosis,. 127 



ness. Yet the condition demanded, the rise of temperature after 

 the use of tubercuUn, is present. 



Again a cow that is closely approaching calving has the tem- 

 perature raised. If tuberculin has been used it is often raised 

 higher than it would be otherwise. It is therefore improper to 

 use this agent on a cow at this period. 



Active exertion, exposure in the hot sun, confinment in a close 

 building, the privation of water at the customary time and other 

 conditions will cause rise of temperature. But such a rise would 

 not imply tuberculosis, even after tuberculin. 



Apart from these and other such causes of error in unskilled 

 hands, the rise of temperature under this test should be taken not 

 as a condemnation of tuberculin, but as a stimulus to search for 

 small occult tubercles. A thorough search will rarelj^ prove 

 fruitless. 



2nd. The temperature sometimes fails to rise under the tuber- 

 culin test, though the animals be in the last stages of tuberculosis. 



This also is true. Here the body seems to be already so 

 saturated with tuberculin, that the small addition made in the 

 test makes no impression, and if we trusted to the reaction alone, 

 we would pronounce the cow free from the disease. But such cases 

 are easily diagnosed without tuberculin. Even the un.skilled more 

 than suspect them, and a physical examination by the skilled 

 practitioner leaves him in no doubt as to their condition. To use 

 tuberculin on such cows is to waste an expensive agent and to 

 run the risk of being misled. Objection based on blunders of this 

 kind is valid enough as an argument against the use of tuberculin 

 by the ignorant and thoughtless, but not against its use by an 

 able practitioner. 



3d. Tuberculin causes reaction in even the slightest cases of 

 tuberculosis, in which the victims would survive for years and 

 might recover. 



This charge is also true, and it is because of its truth that tuber- 

 culin is invaluable and indispensible as a diagnostic agent, in all 

 attempts to put an end to the disease. An eminent German pro- 

 fessor (Eggeling) in objecting to the use of tuberculin as a general 

 test records the following experience. In a herd of 37 reaction 

 after tuberculin occurred in 31, while 6 gave no reaction. When 



