17 



The layer of horn, that covers the frog, is thinner in substance 

 and more delicate in texture, than that of any other part 

 of the foot, and, when once destroyed, is very imperfectly 

 and sparingly reproduced. The first stroke of the knife 

 removes this thin horny covering altogether, and lays bare 

 an under surface, totally unfitted from its moist, soft, texture 

 for exposure either to the hard ground, or the action of the 

 air ; and in consequence of such unnatural exposure it soon 

 becomes dry, and shrinks ; then follow cracks, the edges of 

 wliich turning outwards form rags ; these rags are removed 

 by the smith at the next shoeing, whereby another such 

 surface is exposed, and another foxindation laid for other rags ; 

 and so on, until at last the protruding, plump, elastic cushion, 

 interposed by nature between the navicular joint and the 

 ground, and so essential to its preservation from injury, is 

 converted by the mischievous intei-ference of aii; into the dry, 

 shrunk, rmyielding apology for a frog, to be seen in the feet 

 of almost every horse, that has been regularly shod for a 

 few years. The frog is provided within itself with two very 

 efficient modes of throwing off any superfluous horn, it may 

 be troubled with ; and it is very unwise in man to interfere 

 with them ; the first and most common is the separation from 

 its surface of small bran like scales, which becoming dry fall 

 off in a kind of whitish scurf, not unlike the dust, that 

 adheres to Turkey figs ; the other, which is upon a larger 

 scale, and of rarer occurrence, is sometimes called "casting 

 the frog :" a tliick layer of frog separates itself in a body, 

 and shells off to tlie full as deep, or deeper than a usual 

 paring with the knife ; but it is worthy of remark, that there 



