220 



temperatures at 6 o'clock and continue at regular periods of 

 every two or three hours until six or eight in the evening. 



It is important that a good thermometer be used and that 

 it be held in the rectum, at least five minutes. The six inch 

 Hicks'thermometer is very well adapted to this test. An 

 eight inch thermometer would be better. 



If within eight to eighteen hours after the injection of 

 the tuberculin, the temperature rises li or more degrees, 

 Fah., above the normal, for two or more successive readings 

 the reaction is characteristic and the auimal is tuberculous. 

 But if the temperature rises at one reading, drops to the 

 normal at the next two readings, then rises at the next read- 

 ing, this reaction ("double curve") is not characteristic — not 

 positive that the animal is tuberculous. Such an animal 

 should be re-tested in three to six months. 



The animals should be kept in their stalls under the same 

 conditions each day during the test ; the same quantity of 

 water and food should be given at the same time each day; 

 abrubt changes of temperature in the barn should be 

 avoided. The temperature of cows in heat or in the ad- 

 vanced stages of pregnancy are usually above the normal 

 and they should not be tested at such times. Animals that 

 have been greatly exhausted by excitement or by shipment 

 on cars or boats should be kept isolated in a quiet place for, 

 at least, one week before they are tested. 



All animals that give slight or indefinite reactions should 

 be isolated for three to six mouths and then retested. Some- 

 times the reaction is accompanied by an acceleration of 

 pulse and respirations and may be followed by a brief attack 

 of diarrhcBa and a slight decrease in the flow of milk. But 

 as a rule there are no bad results following the reaction. 



THE ACOURACY OF THE TUBEllCULIN TEST. 



Out of 4,068 animals tested in various parts of the United 

 States by different persons and by the various kinds or forms 

 of tuberculin, 1,137 reacted and 1,118 exhibitted undoubted 

 tuberculous lesions upon post mortem examination ; in 19 

 of these that reacted, the naked eye failed to find any visi- 



