TESTING CREAM BY THE BABCOCK TEST 87 



measure by pipette a sample of cream to be used for 

 testing its fat content is that less cream will be used 

 than should be, and therefore the results will be too 

 low. Any system of volumetric measurement pro- 

 posed is open to some uncertainty and inaccuracy. 

 The use of a pipette in testing cream is justifiable only 

 for work that is not expected to be strictly accurate. 



If one uses a pipette in measuring cream for test- 

 ing, accuracy of results are generally improved by 

 measuring 18 cc. of cream and also rinsing the pipette 

 into the test-bottle with a small amount of water. Pip- 

 ettes are obtained which have an 18 cc. mark as well 

 as a 17.6 cc. 



In several States, laws have been passed making it 

 illegal to test cream in any other way than by weighing 

 the sample to be tested, when the fat is used as a basis 

 of paying for cream. 



WEIGHING SAMPLE OF CREAM 



Using 18 grams. The operation of weighing 

 cream is simple. One places the empty test-bottle on 

 one pan of the scales and balances it by a slide-weight 

 or some form of counterpoise. One then places an 

 i8-grarn weight on the other pan, after which the pip- 

 ette is filled with cream somewhat above the 17.6 cc. 

 mark, and this is run into the bottle, the last portion 

 being run in more slowly until the two scale-pans just 

 counterbalance each other. A little practice enables 

 one to weigh the exact amount rapidly. In case the 

 amount of cream taken in the pipette is not enough, 

 agitate the sample, draw a little into the pipette and 

 run this slowly into the bottle until it counter-bal- 



