QUESTIONS 331 



Strength of Sulfuric Acid. — The strength of acid holds a 

 definite relation to its specific gravity, as shown below : 



Sp. g:. Per cent strength 



1.841 97 



1.840 96 



1.839 95 



1.837 94 



1.834 93 



1.830 92 



1.825 91 



1.820 90 



1.815 89 



1.808 88 



QUESTIONS 



1. When, where and by whom was the Babcock test invented ? 



2. Why do we use a 17.6 c.c. pipette for testing milk? 



3. What is the specific gravity of normal milk? 



4. What is the specific gravity of normal cream? 



5. What is the specific gravity of butter fat ? 



6. Give the name, specific gravity, and strength of the acid used in testing. 



7. How much acid should be used when testing milk? 



8. Should a milk sample be mixed at once after adding acid? 



9. What should be the temperature of milk for testing? 



10. Should the test bottles be kept warm while in the tester? 



11. How should a milk test be read? 



12. Describe the appearance of a perfect test. 



/ 13. Wherein and why does the testing of cream differ from that of milk ? 



14. How would a cream test be read? Why? 



15. How would you test skim milk? 



16. How much acid would you use in testing skim milk? 



17. How would you test whey? 



18. How would you test buttermilk? '* s - 



19. How would you test cheese? 



20. How would you test sour milk ? 



21. What would you do if the water were very hard? , 



22. How would you determine whether the acid was of proper strength? 



23. Would chemically pure acid give better results? 



24. Would it change the reading of a test to run the tester too fast? 



25. What style of test bottle is best for testing milk? 



26. What color should the testa be just before they are put in machines ? 



27. What can be done in case they are getting too dark? 



28. Would a closed machine do better work than an open one? 



29. How may a hand tester be heated on the farm? 



30. What is a centrifuge? 



