TUBRRCULIN TEST 



221 



understand, as far as possible, the reason for the exceptions 

 and the extent to which they occur. The reported failures of 

 the tuberculin tests fall into two distinct classes. 



ynii-r.'^ 



Fig. S r. A temperature curve of three cows after injecting tuberculin. 

 I a heatthy cow, 2 and 3 tuberculous ones. 



Fig. 52. Chart showing the effect of drinking cold water upon the 

 temperature of a cow. 



I. There is a reaction and no disease is found. In 

 explaining this alleged error, the records of the cases which 

 have come to my attention have been so deficient in data con- 

 cerning the normal temperature variation of the animals, and 



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