BULK IN FOOD. 45 



Husk of Grain. The office of the husk of grain ap- 

 pears to be to furnish mineral matters, and to give bulk 

 to the food. It also seems, by mechanical irritation, 

 to increase the vermicular motion of the bowels, in order 

 to obviate the ill-consequences which might arise from 

 the decomposition, in the intestines, of the unassimilated 

 nitrogenous matters of the corn, a possibility likely to 

 occur owing to the unstable nature of the compounds of 

 nitrogen. Both from theory and practice we may safely 

 conclude, that the husk should not be removed from the 

 grain which the horse is to consume. 



We may see, from the foregoing observations, that 

 the working parts of the animal machine are formed of 

 nitrogenous and mineral substances, with a small amount 

 of fat; while the motor power is obtained from heat 

 generated by the oxidation of fat, and also of the com- 

 ponent parts of the machine itself. 



Bulk in Food. The fact of the large capacity of the 

 horse's intestines indicates that his food should be of a 

 bulky nature, so that they may be able to act properly 

 on it by their wormlike (peristaltic) motion, which causes 

 it to become thoroughly mixed with the intestinal juices, 

 its various particles to be presented to the absorbants 

 which take up the nutrient matter and the remainder 

 to be expelled onwards. If this condition of bulk be 

 not complied with, the digestive apparatus will get out 

 of order, however accurately materials for bulding up 

 tissue be supplied. Indigestible woody fibre contained 

 in large quantities in the various grasses and unassimi- 

 lated starch, chiefly serve the required purpose. That, 

 within certain limits, the measure of a horse's appetite 



