164 COMPOSITION OF MILK. 



milk they are able to sell with a safe conscience, 

 though it may be doubted if the true morality of the 

 case is much better than if the pump had been called 

 directly into action. 



From 3 to 5 lbs. in each 100 lbs. of milk, are curd, 

 or casein; this is a nitrogenous body like gluten, al- 

 bumen, animal muscle, and the others we have 

 named in a previous chapter. Casein is a white, 

 flaky substance, and can be separated from the milk 

 in various ways ; these will be specified when we 

 come to write particularly of cheese, and cheese 

 making. There are also in every 100 lbs., from 4 to 

 5 lbs. of a species of sugar, called milk sugar; this is 

 not so sweet as cane sugar, and does not dissolve so 

 easily in water. It may be obtained by evaporating 

 down the whey, after separation of the casein or curd. 

 In Switzerland it is made somewhat largely, and used 

 for food. 



The butter or oil amounts to from 3 to 5 lbs. in 

 every 100 of milk. Lastly, the ash is from J to 

 I lb. in each 100. This ash is rich in phosphates, 

 as shown in the following table ; it represents the 

 composition of two samples, each of the ash from 

 1000 lbs. of milk 



TABLE XI. 



No. 1. No. 2. 



Phosphate of Lime, "23 .... -34 



Phosphate of Magnesia, "05 .... "07 



Chloride of Potassium, '14 .... '18 



Chloride of Sodium (com. salt), . "02 .... '03 



Free Soda, '04 .... -05 



0-50 0-67 



We shall refer to this table again. 



The butter, as stated above, is from 3 to 5 lbs in 

 each 100 of milk. It exists in the form of minute 

 globules, scattered through the liquid. These glo- 



