THE GREASE. 71 



Whatever disturbs any of these functions 

 will produce debility. In a full plethoric habit, 

 the vessels which are appropriated for the cir- 

 culation of the blood become oppressed by being 

 overloaded, and are thus rendered incapable of 

 performing their office. Hence debility takes 

 place, and the legs, which, by their situation, 

 are most remote from the center of circulation, 

 and through which the blood has to return in 

 opposition to its own gravity, become swelled 

 for want of the accustomed absorption. On the 

 other hand, when the horse is lean and emaci- 

 ated, either from want of a sufficient quantity of 

 nutritive food, or from excessive labour, the 

 circulation of the blood will be languid from a 

 deficiency of stimulus, and debility will naturally 

 ensue. 



In addition to either of the above-mentioned 



causes, the following may be given as collateral 



promoters of the disease, viz. the season of the 



year, unnatural confinement in the stable, the 



F 4 acclivity 



