364 PHYSIOLOGY AT THE FAEM. 



with turnips or potatoes, 3 or 4 Ib. a- day of the cake will 

 suffice. 



The following is Professor Johnston's analysis of the oilcake 

 of commerce : 



Water, 



Mucilage, .... 



Albumen and gluten, . 



Oil, .... 



Husk, . 



Ash and sand, 



100.00 100.00 



The large percentage of proteine compounds is nearly equal 

 to that of pease and beans, a result very unexpected, since the 

 utility of oilcake in feeding has been usually believed to arise 

 from its laying on fat. The proportion of oil is greater than 

 in any of the cereals, since the oat has no more than 7 per cent 

 of oil, while oilcake has as much as 1 2 per cent. 



Oilcake leaves 6 per cent of ash, the composition of which 

 is as follows : 



English. American. 



Alkaline salts, . . . 31.55 38.20 



Phosphate of lime and magnesia, . 47.67 56.26 



Lime, .... 4.88 1.24 



Magnesia, . . . . 1.51 trace. 



Silica, .... 10.81 4.30 



Sand, . 3.58 



100.00 100.00 



The American cake appears to be a cake of pure quality. 

 The phosphates are in large proportion, even twice as available 

 for making bone as oats or barley. The dung derived from 

 oilcake is more enriching to the soil than that even from 

 grain, inasmuch as it contains more phosphates than the ani- 

 mals can take up, so that the excess must pass into the dunghill. 



