FIFTIETH ANNUAL CONVENTION 119 



taneous tissue. If an animal is tuberculous, the action of 

 the tuberculin causes a fever, which is indicated by a rise in 

 temperature. This rise, under ordinary conditions, may oc- 

 cur any time/ between the eighth and twentieth hours after 

 to measure the temperature before the eighth hour and con- 

 tinue to the twenty-fourth hour or longer. 



The temperatures are measured at least 3 times in ad- 

 vance of the injection, at 2-hour intervals, to learn whether 

 the animal is in proper condition to receive the test. The 

 temperatures after injection are taken every 2 hours until 

 the test is completed. The proper interpretation of the tem- 

 peratures is made by the person applying the test, and a 

 careful observance of any cilinical changes is always impor- 

 tant in determining the result. It can not be set forth too 

 strongly that the test, including the two following methods, 

 should be attempted only by those who are properly quali- 

 fied to do the work. 



The Intradermic Test (Into the Skin). 



The intradermic test for detecting tuberculosis is used 

 to a considerable extent because of its convenience. When 

 made by those who have become skilled in its application, 

 it is very accurate. In this test the tuberculin is injected 

 between the layers of the skin, only a few drops being used, 

 and it is usually applied in the region at the base of the tail, 

 where the skin is soft and nearly hairless. The intradermic 

 test is satisfactory also for the diagnosis of tuberculosis in 

 swine, and when so used the tuberculin is applied into the 

 skin of the ear near its base. 



The reaction from the intradermic test consists of a 

 swelling at the point of injection and is usually observed 

 from 72 to 120 hours after the injection. The character of 

 the swelling varies, and a proper diagnosis of tuberculosis 

 by this test can be made only by an experienced person. 



The Ophthalmic Test (Into the Eye). 



Still another method, known as the ophthalmic, is used 

 to some extent and has been found to be of considerable 

 value in what is known as "check" testing; that is, it is 



