TUBERCULOSIS 169 



EXERCISES 



1. Why. take several temperatures of an animal be- 

 fore injecting tuberculin? 



2. "Why are several temperatures taken after the 

 injection is made? 



3. What would be the effect of allowing a cow being 

 tested for tuberculosis to have all the ice cold water she 

 could drink? 



4. Why not buy cattle that have not been tested for 

 tuberculosis ? 



5. Did you ever test the home herd for tuberculosis ? 



6. Is there any possibility that you may have tuber- 

 culosis in your home herd ? 



LABORATORY PROBLEMS 

 XXV. To Test Milk Which Has Become Cubdled 



The difficulty in testing milk which has become 

 curdled lies in the fact that it is very hard to sample 

 such milk accurately. 



a. Make a test of a well-mixed quantity of sweet milk 

 and record the results in a notebook. 



b. Set aside a small quantity of the same milk and 

 allow it to curdle. Care must be exercised to prevent 

 evaporation. 



c. After it has curdled, add 10 c.c. of ammonia per 

 100 c.c. of sample to dissolve the curd. If this quantity 

 of ammonia will not dissolve all the lumps, add a few 

 more c.c. of ammonia. 



d. Test as in the case of sweet milk. Great care 

 must be exercised while adding the sulphuric acid. For 

 this reason it is best to add only a cubic centimeter or 

 two at first and then gently shake the mixture. After 



