CBEAM. 53 



SAMPLE VI. From another dairy, a very thick cream. 



In 100 parts by weight 



Water . ,* . . . ^ 50.00 



Fat . . .; ' . ^ 43.90 



Caseine and milk-sugar . . *. 5.63 



Ash . . . . i: - . -.... 0.47 



100.00 



Every one of these creams is genuine and unsophisti- 

 cated. It is instructive to compare the percentages of fat in 

 the different creams. 



Cream I. 19.00 fat per cent. 

 " II. 14.1 " 



" III. 18.87 " 

 " IV. 33.02 " 

 " Y. 38.17 " 

 " VI. 43.9 " 



If we regard the determination of fat in Cream II. as 

 questionable (for a reason to be presently explained), and if 

 we accept the determination of fat in Cream I., to which the 

 objection does riot apply, and if we also accept the high 

 yields of fat to which no objection can be raised, we are led 

 to the conclusion that cream is sometimes twice as rich in 

 fat as it is at other times. And that being granted, what 

 becomes of the creamometer, regarded as an instrument of 

 precision ? 



The rise of the cream is a physical phenomenon, depend- 

 ing on the difference in density between the globules of fat 

 and the liquid in which they were floating, and also on the 

 size of the globules. The difference between the cream and 

 the skim-milk which has thrown it up is, that the former is 



