10 Testing Milk and Its Products. 



for twenty minutes at a rate of 2000 revolutions per 

 minute at 55 C (131 F.). The reading of the cream 

 layer thus obtained gives the per cent, of cream, and 

 not of butter fat, in the sample tested. One hundred 

 and nine-two samples of milk can be tested simultan- 

 eously. Within the limits of normal Danish herd milk, 

 the results obtained correspond to the percents of fat 

 present in the samples, one per cent, of cream being 

 equal to about 0.7 per cent, of fat; outside of these 

 limits the test is, however, unreliable, especially in case 

 of very rich milk and strippers' milk. Only sweet milk 

 can be tested by this method. The recent introduction 

 of milk tests proper into Denmark, like the Gerber, Bab- 

 cock and De Laval tests may, however, in time force the 

 Fjord cream test out of Danish creameries, for similar 

 reasons that relegated to obscurity the gravity cream 

 tests (creamometers). 1 



i Among foreign milk tests in use abroad should also be mentioned the 

 Wnllnji Refractomcter, which, in the hands of a trained chemist, is better 

 adapted for use where n very large number of samples are to be tested at 

 a time, than any other milk test available. 



