ON MILK AND MILK-TESTING 2/ 



What is the specific gravity of milk protein? 



It is held by some that the specific gravity of 

 milk protein is about 1.34. 



How does milk fresh from the cow differ in specific 

 gravity from milk several hpurs old? 

 Fresh milk has a lower specific gravity, due in all 

 probability to the gases in the fresh milk. For this 

 reason milk should be several hours old when tested 

 if accurate results are desired. 



What is a lactometer? 



It is a form of hydrometer made especially for 

 taking the specific gravity of milk. 



What two forms of lactometers are in common 

 use? 



The Quevenne lactometer and the New York 

 board of health lactometer. 



Describe a Quevenne lactometer. 



It consists of a hollow, cylindrical body so 

 weighted at one end that when floated in milk it 

 takes an upright position. A stem is attached to 

 the upper end of the body. The stem contains a 

 scale so graduated and set that when the instru- 

 ment is floated in the milk the specific gravity may 

 be read at the upper surface of the liquid. The 

 better class of instruments contain a thermometer, 

 the bulb being melted in the lower end of the body 

 and the scale appearing directly over the lactometer 

 scale. 



