ANIMALS AND THEIR PRODUCTS. 129 



give I of one per cent, of ash, or inorganic matter, if 

 burnt. 



231. The ash of milk consists of phosphate of lime, 

 phosphate of magnesia chloride of potassium, chloride 

 of sodium and soda. Of these inorganic or mineral 

 substances, about one- half is phosphate of lime. Hence 

 the importance that cows should be supplied with this 

 substance, for they can give us nothing in their milk 

 which they do not receive in their food. Oil-cake, 

 corn-meal, hay from well-manured lands, and grass on 

 rich pastures, contain sufiScient of it for their purpose; 

 while sour water-grass, and the grass on worn-out 

 lands, is deficient in it. Cows kept on such feed, as 

 before stated, should be supplied with phosphate of 

 lime (bone-dust). If it can be procured in no other 

 way, bones may be calcined (burnt in the fire till they 

 readily fall into powder), and given ,to them, as they 

 are fed with salt. 



232. It will be noticed that another of the inorganic 

 substances in milk is chloride of potassium. Some 

 farmers have adopted the practice of mixing ashes 

 with the salt given to their cows. I doubt whether 

 this is well, for it will compel them to eat the ashes, 

 in order to get the salt. It would seem a wiser course 

 to place the ashes in a separate trough. The instinct 

 of the animals would be a safer guide, as to whether 

 they need more chlorine and potassium than are con- 

 tained in their food. If they do, they * would lap 

 ashes, which contain one of these elements, while their 

 salt contains the other ; but if they do not, then the 



