386 



THE CHEMICAL CONTROL OF THE DAIRY. 



The milk was curdled by phosphoric acid ; 60 c.c. of the whey 

 were distilled : 



The first 10 c.c. took 



second 

 , third 



1-3 c.c. ^alkali. 



1-8 

 1-9 



It was evident that the milk contained an acid somewhat less 

 volatile than water ; this corresponds with acetic acid, and the 

 whey distilled as a solution containing 0-11 per cent, of acetic 

 acid, which is equivalent to 2 per cent, of vinegar. 



Example c. The milk had a faint burnt taste. 



It contained 042 per cent, soluble albumin. 



On centrifuging, a deposit was obtained which appeared to 

 consist of proteid matter ; it was much browned. It was there- 

 fore concluded that the milk had been placed in a vessel, in 

 which burnt milk had previously been kept. 



Example d. The milk tasted burnt. 



The following analytical figures demonstrated that the milk 

 had been boiled : 



Fat, . . 

 Cream in six hours, 

 Soluble albumin, 



3-72 percent. 

 1-3 



trace. 



It was concluded that the milk had been burnt in boiling. 

 Example e. The smell and taste were unpleasant, but could 

 not be identified. 



The following analytical figures were obtained : 



Specific gravity, 

 Total solids, 

 Pat, . 

 Milk-sugar, 

 Protein, 

 Ash, . 

 Solids not fat, 



1-0292 



13-22 percent. 

 4-82 

 4-34 

 3-36 

 0-70 

 8-40 



The sediment obtained by centrifuging contained much mucus 

 and cells from the udder. 



It was concluded that the milk was the product of a cow in 

 ill health. 



It is evident that if dirty water has been added to milk, an 

 evil smell and taste may occur ; no further example need be 

 given of this. 



Turnips and other substances eaten by the cow or, what is 

 more likely, handled by the milker, may communicate a taste 

 to the milk. The action of certain organisms may have a similar 

 effect. The author is unacquainted with chemical methods of 

 identifying these causes. 



