Animal Heat. 37 



healthy, and is prone to disease in consequence 

 of the absence of movements which promote vital 

 action. 



These facts are well known to practical horse 

 owners, and they in consequence always avoid fat 

 animals for immediate active work, and delay 

 until the place is occupied by muscle. 



We thus perceive that in feeding fatting 

 animals and working horses two opposite prin- 

 ciples must be carried out. It would be as absurd 

 to feed a hunter or draught horse on the materials 

 given to the cow or ox in the feeding house, as 

 to expect they should replace each other in the 

 scale of usefulness to man. 



These facts dispose of the first and second 

 propositions. We find that food is nutritious 

 when it can minister to the formation and develop- 

 ment of the body, and maintenance against waste ; 

 while substances of a mixed character are needed 

 in order to keep pace with the requirements of 

 the body in the production of a necessary tem- 

 perature, and assistance in the accumulation of 

 vital force. 



Without materials specially provided for the 

 latter process our working animals would be re- 

 duced to the condition of flesh-eating or caged wild 

 creatures, with this serious disadvantage, the work 

 imposed might act prejudicially, as it would not, 

 in all cases, be so nicely proportioned as to suit 

 the wants of the system, or when taken in accord- 

 ance with the promptings of instinct in the 



