Grade . 

 Date. . 



(20) 



EXERCISE 4. 



Object. — To make a test of milk for butterfat, by the Babcock method. 

 Apparatus. — Two whole milk bottles; a 17.5 cc. pipette; acid measure; 



acid; sample of whole milk; two sample bottles; hot water bath. 

 Step 1. Practice using the pipette 



with water until you can 



reasonably adjust the 



amount to be taken; 



17.6 cc. 



Correct manner of taking reading 

 with calipers. 



Correct position for tilling bottles, 



Step 2. Always have milk between 60° and 70° F. before drawing sample 



with pipette. 

 Step 3. Mix the milk thoroughly by pouring from one vessel into another 



before drawing sample. Always pour down the side of the vessel. 

 Step 4. Put 17.6 cc. of milk into each of two whole milk bottles. Allow the 



milk to run down along the neck by holding the pipette and bottle 



at an angle of about 60°. (Letter one sample "A" and the other "B".) 

 Step 5. To each bottle add 17.5 cc. of sulphuric acid (1.82 to 1.83 s. g.), 



using an acid measure. Turn bottle slowly as acid is added, allowing 



acid to run down the sides of the neck. 



