CHEMICAL TESTS AND ANALYSES 351 
Butter Fat. 
The Babcock Test. 
Standard Glassware.’ 
(a) Standard milk test bottles. graduated to & per cent and 
with sub-divisions of .1 per cent. 
(b) Standard pipette graduated to 17.6 cc. 
(c) Acid measure graduated to 17.5 c.c. 
(d) Centrifuge-Babcock tester. 
(e) Water bath for reading at 130 to 140 degrees F. 
(f) Calipers for measuring fat column. 
(g) Sulphuric acid, specihe gravity 1.82 to 1.83. 
Determination. 
Pipette 17.6 cc. of the properly mixed sample of milk into 
the milk test bottle. Add 17.5 c.c. of acid and shake until all the 
curd is completely dissolved. 
Both mills and acid should have 
a temperature of 53 to 70 de- 
grees F, Tf milk and acid are 
too warm, set the sample bot- 
tles and the acid jar into a 
trough or tub of water at 35 to 
70 degrees F. for thirty minutes 
before testing. The test bottles 
containing the mixture of milk 
and acid are then whirled in 
the Babcock tester for five 
minutes at about one thousand 
revolutions per minute, in the 
case of a tester with a twelve- 
inch diameter wheel. Full the Sie 416; “Baweock taater 
test bottles to the bottom of Courtesy of Creamery Package Mfg. 
the neck with hot water. The ce 
water should be soft, preferably rain water or distilled water. 
If hard tap water is used it should be boiled to precipitate the 
carbonates, otherwise the test may be difficult to read, owing to 
the presence of bubbles of gas on top of the fat column. Revolve 
1 Hunziker, Indiana Agricultural Experiment Station, Circulars 41 and 42, 
1914, 
