152 DAIRY CHEMISTRY 



sary? 33. What is the pipette? 34. How is milk meas- 

 ured with the pipette ? 35. How much milk does the pipette 

 deliver? 36. What is the test bottle? 37. How is the 

 scale made to read ? 38. How would you measure acid and 

 pour it into the test bottle? 39. After adding the acid, what 

 is the next step in the test? 40. How is the test completed? 

 41. How is the fat read? 42. What precautions should be 

 taken in reading the fat? 43. What causes some tests to 

 show particles of casein below the fat in the test bottle ? 44. 

 Why are some tests black or charred ? 45. How would you 

 determine whether a test bottle is correctly graduated or not? 

 46. Why is it necessary to have accurately graduated test bot- 

 tles ? 47. What causes the separation of the fat in the test ? 

 . In the handling of the acid what precautions are to be 

 observed? 49. How can the machine be speeded? 50. Why 

 should the number of revolutions per minute vary with the 

 diameter of the machine? H>1. What is a composite sample? 

 52. What material is used for its preservation ? 53. How 

 long should the composite sample be kept? 54. What is a 

 convenient way for handling and measuring the preservative ? 

 55. What kind of bottles should be used for the composite 

 sample? 56. How is skim milk tested? 57. How is the fat 

 content in skim milk read? 58. What effect does partial 

 freezing have upon the composition of milk? 59. How 

 should the glassware used in making the test be cleaned? 



60. What kind of water should be used in making the test? 



61. Why are some waters objectionable ? 62. What are some 

 of the necessary precautions to take in milk testing? 



CHAPTER III 



63. Of what are the fat globules of milk composed? 64. 

 What are the three elements of which fats are composed? 



65. Name the different fats of which butter is composed. 



66. To what extent are these fats present? 67. Name the 

 three classes into which these fats may be divided. 68. Give 



