222 



TUBERCULOSIS 



the incompleteness of the post-mortem examinations, that it 

 seems possible for the error to rest with the observer quite as 

 much as with the tuberculin. Unfortunateh' we are as yet 

 unable to determine by the reaction the extent of the disease, 

 so that a beginning lesion no larger than a walnut may cause 

 a pronounced rise of temperature and such a tubercle may be 



Fig. 53. Temperature curve of a hog. Dotted line A represents temper- 

 ature of a hog for 2/ hours before the injectiott of tuberculin. The 

 fill line B represents the temperature of the hog for 24 

 hours after the injection of tuberculin {Schroeder) . 



difficult to find, especially if located in the marrow of some 

 bone or in the nervous system. 



2. There is no reaction and the disease exists. It is 

 generally admitted that advanced cases often fail to react, but 

 here the test itself is of little importance, as the disease can 

 be detected by the clinician on physical examination. When, 

 however, tuberculin is carefully prepared and scientifically 

 administered, these exceptions are exceedingly rare. It seems 

 to act always in active tuberculosis. 



