EXCREMENTS AND URINE. 83 



the urine. For this loss, the body receives compen- 

 sation through the last-named means of nourishment. 

 By very plentiful foddering with nutrients of this 

 description, more flesh is produced than that which 

 disappears by the formative and destructive processes 

 we have mentioned : the animal is fattened, and in 

 this case it increases not merely in fat, but also in 

 flesh. 



The integrants of the ordinary food of cattle may 

 be thus arranged : — 



1. Elements of respiration (the constituents free 

 from nitrogen) : 



Vegetable fibre, starch, gum, sugar, fat, and 

 fat-oils. 



2. Plastic or flesh-forming elements of nutrition 

 (the constituents containing nitrogen) : 



Vegetable albumen, vegetable caseine, and 

 gluten. 



3. Bone-forming substances (the mineral constitu- 

 ents) : 



Potash, soda, lime, magnesia, silica, sulphuric 



acid, phosphoric acid, and muriatic acid 



(chlorine). 



The first two classes are also called organic or 



combustible, in opposition to the mineral substances, 



which are also designated inorganic, incombustible, 



or ashy constituents of plants. 



The non-azotized constituents predominate gen- 

 erally in plants, but their proportion to those con- 

 taining nitrogen varies exceedingly in their different 



