The Animal Body. 



209 



her of animals, have been determined by Lawes and Gilbert at 

 the Rothamsted Station. The following table shows the per- 

 centage composition of the whole bodies of various farm animals. 

 The fat pig was one grown for fresh pork, not for bacon. Store 

 animals are those in good flesh, but not fat. 



Composition of Farm Animals. 



It will be noticed that in nearly every case water is the largest 

 ingredient of the animal body. The proportion of water is great- 

 est in young and lean animals and diminishes toward maturity 

 and especially during fattening. The proportion of nitrogenous 

 matter and ash tends to increase as the animal ages, but dimin- 

 ishes during fattening. The half fat ox contains 6 per cent more 

 water than the fat; the store sheep 14 per cent more than the 

 extra fat, and the store pig 14 per cent more than the fat. The 

 fattening process does not involve a replacement of the water 

 already in the tissues, but the increase is much more largely dry 

 matter. Because this increase during fattening is largely fat, 

 the proportion of protein and ash in the dry substance of the 

 fattened animal has decreased relatively. 



The largest proportion of nitrogenous matter a*nd ash are 

 found in the ox, the smallest in the pig. The difference in the 

 proportion of ash is chiefly due to the wide difference in the 



