BULK IN FOOD. 55 



the fluids and ashes of these tissues, but they probably 

 exert the same general influence as those of soda. . . 

 The presence of the earthy salts, on the other hand, 

 would seem to have reference almost exclusively to the 

 composition of the tissues, into which some of them 

 enter very largely." (Carpenter.) Iron is princi- 

 pally found in the red corpuscles of the blood, in the 

 muscles, and in the hair. 



Husk of Grain. The office of the husk of grain 

 appears to be that of furnishing mineral matters, and of 

 giving bulk to the food. It also seems, by mechanical 

 irritation, to increase the wormlike motion of the 

 bowels, which tends to obviate the ill-consequences 

 which might arise from the decomposition, in the in- 

 testines, of the unassimilated nitrogenous matters of 

 the corn ; a possibility likely to occur owing to the un- 

 stable 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 ; the motor power being obtained from 

 heat generated by the oxidation of fat, and also of the 

 component parts of the machine itself. 



Bulk in Food. The fact of the horse's intestines 

 being of large capacity, indicates that his food should 

 be of a bulky nature. The intestines have a wormlike 

 motion, which causes the food to become thoroughly 

 mixed with the intestinal juices, its various particles to 

 be presented to the absorbents which take up the 



