104 MANUAL OF GENEEAL AGEICULTUEEI. 



grams in weights/on-one side. Take the sample of cream 

 to be tested and warm it by shaking the cream and vessel 

 in a pail of water as hot as the hand will bear for one or 

 two minutes. (The cream should not rise above 90 F). 

 Mix by pouring from one bottle to another four or five 

 times. Suck up the cream into the milk pipette until 

 the upper level is an inch or so above the 17.6 c.c. mark. 

 Gradually let it run into one of the bottles until the 

 scales just balance. Remove the weights, leave both 

 bottles on, and in a similar manner pour cream from the 

 same sample, or another sample to be tested, into the 

 empty bottle on the other side until the scales just 

 balance. Add the acid and complete the test the same as 

 for milk. 



Unless the reading is done quickly the bottles should 

 be placed in water from 140 to 150 F., the water rising 

 nearly to the top of the necks. Let them remain there 

 five minutes, then perfectly clear readings can be ob- 

 tained. This is necessary when several samples are to 

 be tested by one operater, as the fat will contract from 

 the cold and slip down the neck before all can be read. 



77. THE BABCOCK TEST OF SKIM MILK. 



Materials: Skim milk bottle, 17.6 cc. pipette, acid 

 cylinder, sulphuric acid, half pint of separator skim milk. 



The Babcock test of skim milk, butter milk, and 

 whey is^the same as that of milk except as indicated in 

 this experiment. 



A double necked test bottle is made especially for 

 measuring small amounts of fat. The smaller neck will 

 measure .25 of one per cent, each of the smaller gradua- 

 tions representing .01 of one per cent. 



To make a test measure out 17.6 c.c. of skim milk 

 with a pipette as was done with milk and then pour it 

 into the larger neck of the skim milk bottle. Next slowly 

 add the sulphuric acid, but instead of using 17.5 c.c. of 

 acid use 20 c.c. Place in the tester with the filling tube 

 toward the center. Whirl and add water in the usual 

 manner, but it is highly desirable to use either distilled or 



