THIRTY-SEVENTH ANNUAL CONVENTION. 187 



diseased germ has just been introduced, before it is time for the 

 disease to have been formed, then you will not get a response. 

 The response is due to the reaction. You take into the body of 

 the animal the tubercular baccilli and it will take ten days to 

 get a response. During that period you will not get a response 

 because there is no tubercular system where you can get a sharp 

 response. Where animals have been just exposed but are not 

 actually diseased you will not get a positive reaction. 



Member : I have heard it said that in the advanced stages 

 there might be a reaction in less than eight days. 



Dr. Russell : Where there is any reason to expect that 

 there is an advanced stage of this disease you can frequently 

 tell in two or three days. I heard a man say he got a response 

 in four hours, but I have never come in contact with anything 

 of the kind. 



Member: How much tuberculin do you use on a six- 

 months-old calf? 



Dr. Russell: Generally speaking two cubic centimeters to 

 a thousand pounds of live weight; but the matter of dosage is 

 not very important. 



Member : When tuberculin is injected into the body does it 

 not hasten the disease? 



Dr. Russell : It does not produce any effect. It does not 

 hasten or cause the disease to progress more rapidly than it 

 would otherwise. 



Member : Why is it in some instances where the animal 

 has responded that in two months later it will not react? 



Dr. Russell : I answered that question a while ago. You 

 must allow a sufficient length of time to elapse between the tests, 

 and you cannot always get a response until after sixty days has 



