New York Agricultural Experiment Station. 315 



at 60° C. for a few hours, after which the drying is completed in a 

 vacuum over sulphuric acid. The analytical results are given in 

 the table following: 



Table V. — Composition of Insoluble Portion (" Separator Slime ") of Milk. 



The figures in Table V, obtained by direct analysis of the insoluble 

 deposit or " separator slime," show a striking agreement with the 

 results obtained by the indirect method, which is brought out more 

 clearly by expressing the above figures in the form of gram equiva- 

 lents, as follows: 



Table VI. — Amounts of Acids and Bases Expressed as Gram Equivalents. 



Sample of deposit taken. 



Casein as gram 



equivalents of 



acid. 



Phosphates as 



gram 



equivalents 



of di-basic 



acid. 



Sum of gram 



equivalents of 



casein and 



phosphates. 



Gram equiva- 

 lents of 

 calcium. 



After 1st run 

 After 6th run 

 After 12th run 

 After 18th run 



77.7x10 

 81 . 1 



80.8 " 

 82 . 8 



100.7 x 10 

 82.9 



88.1 

 87.8 " 



178.4 x 10" 

 164.0 

 168.9 

 170.6 " 



169.3 x 10 

 162 . 3 

 167.2 

 161.2 



The high percentage of inorganic phosphorus in the deposit from 

 the first run indicates that the phosphates are heavier than the 

 caseinates and could be separated from them if a certain speed were 

 used in running the separator. This point is further shown by the 

 following experiments: In the first experiment, the bowl of a cream 

 separator was filled with fat-free milk (about 1,000 c.c.) and was 

 whirled for two hours, at a speed of 5,000 revolutions per minute, 

 when the milk was taken out and the "separator slime "which had col- 

 lected on the bowl was removed and treated with alcohol and ether 

 in the manner already described. The same milk was returned to 

 the separator bowl and again whirled for two hours, when the deposit 

 was again removed and treated as before. When removed the second 

 time, that is, after four hours of whirling, the milk was nearly as 

 clear as whey, most of the suspended phosphates and casein having 



