BACILLUS OF TUBERCULOSIS. 293 



temperature of each animal can be recorded in its 

 appropriate place without danger of confusion. The 

 following procedure has been used extensively and has 

 given excellent results : 



" (a) Take the temperature of each animal to be tested 

 at least twice, at intervals of three hours, before tuber- 

 culin is injected. 



" (b) Inject the tuberculin in the evening, prefer- 

 ably between the hours of six and nine. The injection 

 should be made with a carefully sterilized hypoder- 

 matic syringe. The most convenient point for injec- 

 tion is back of the left scapula. Prior to the injection 

 the skin should be washed carefully with a 5 per cent, 

 solution of carbolic acid or other antiseptic. 



" (c) The temperature should be taken nine hours 

 after the injection, and temperature measurements 

 repeated at regular intervals of two or three hours 

 until the sixteenth hour after the injection. 



" (d) When there is no elevation of temperature at 

 this time (sixteen hours after the injection) the exam- 

 ination may be discontinued; but if the temperature 

 shows an upward tendency, measurements must be con- 

 tinued until a distinct reaction is recognized or until 

 the temperature begins to fall. 



" (e) If a reaction is detected prior to the sixteenth 

 hour, the measurements of temperature should be con- 

 tinued until the expiration of this period. 



" (/) If there is an unusual change of temperature 

 of the stable, or a sudden change in the weather, this 

 fact should be recorded on the report-blank. 



" (g) If a cow is in a febrile condition tuberculin 

 should not be used, because it would be impossible to 

 determine whether, if a rise of temperature occurred, 

 it was due to the tuberculin or to some transitory illness. 



