FROG PRESSURE. 15 



the unreasoning, it has been one of the opin- 

 ions of grooms and farriers that this callous, 

 india-rubber-like substance would wear away 

 upon exposure to the action of the road or 

 pavement, and it has been one of their cherish- 

 ed practices to set .the horse up upon iron, so 

 that he could by no possibility strike the frog 

 upon the ground. 



In addition to this violation of nature, they 

 pare away the exfoliating growth of the or- 

 gan, and trim it into the shape that suits 

 their fancy. 



Without action, muscular life is impossible, 

 the portion of the body thus situated must 

 die, paralyzed or withered. Motion, use, are 

 the law of life, and the frog of the horse's 

 hoof with a function as essential and well-de- 

 fined as any portion of his body is subject to 

 the general law. Without use it dries, har- 

 dens, and becomes a shelly excrescence upon 

 a foot, benumbed by the percussion of heavy 

 iron upon hard roads. This is a loss nature 

 struggles in vain to repair, the horse begins 

 to fail at once. The elastic step, which in a 

 state of nature spurned the dull earth, becomes 



