^78 



EXPERIMENT STATION RECORD. 



Seven ty-niue samples of creamery butter and 23 samples of farm 

 butter were analyzed during the year; the average composition of both 

 classes of butter, with extremes, was as follows: 



Composition of farm and creamery butter. 



The author states that the per cent of water in the butter seems 

 dependent on Avhether water or skim milk is used for washing the but- 

 ter in taking it out of the churn. Eight samples washed with water 

 contained from 14.62 to 16.87 per cent of water, with an average of 

 15.42, while 6 samples treated with some skim milk at the end of 

 the churning contained from 13.86 to 15.92 per cent of water, with an 

 average of 14.51, or nearly 1 per cent less where skim milk was used. — 



F. W. WOLL. 



The loss of total solids in milk on keeping, E. J. Bevan {Ana- 

 lyst, 19 (1894), Nov., pp. ^ii-55(9).— Samples of milk which were weighed 

 out in platinum dishes and placed in desiccators until the following 

 morning before evaporating were found to differ in total solids from the 

 calculated results by about 1 per cent. Experiments were then made 

 in evaporating samples of milk at once and after standing 24, 48, and 120 

 hours, which showed that there was a considerable decrease in the per- 

 centage of total solids, amounting to 0.94 after 24 hours and to 2.31 per 

 cent after 120 hours. The author has found that lactic acid is volatile. 

 When 0.1445 gm. of pure lactic acid was added to 5 gm. of fresh milk 

 the solids obtained amounted to 0.6610 gm., as against 0.5784 gm. in 

 the original milk, corresponding to a loss of 42.8 per cent of the lactic 

 acid added. When the samples were neutralized the loss in total 

 solids in keeping was considerable less than when not neutralized. 

 There was found to be " absolutely no connection between the loss and 

 the percentage of acid formed." The impossibility of accurately com- 

 pensating for the loss of solids in samples of milk partly decomposed, 

 as is now practiced by the Government chemist, is insisted upon. 



In the discussion following Mr. Eichmond said that in a series of 

 experiments which he had made some years since he had found that 

 lactic acid, especially in concentrated solution, was distinctly volatile 

 when distilled with water. From Mr. Bevan's figures it appeared, 

 roughly speaking, that the greater the amount of acid formed the less 

 the loss of total solids, a fact which his own experience confirmed. In 



