380 INFLAMMATION OF THE FOOT, OR ACUTE FOUNDER. 



and answering several important purposes, being an elastic bed on which the navi- 

 cular bone and the tendon (see page 345) can play with security, and without 

 concussion or shock, by which all concussion communicated to the cartilages of 

 the foot are destroyed by which these cartilages are kept asunder, and the expan- 

 sion of the upper part of the foot preserved. As the descent of the sole increases 

 the width of the lower part of the foot, so the elevation of the frog, a portion of 

 it being pressed upward and outward by the action of the navicular bone and 

 lendon, causes the expansion of its upper part. Precisely as the strong muscle 

 peculiar to quadrupeds at the back of the eye (see page 127), being forcibly 

 contracted, presses upon the fatty matter in which the eye is imbedded, which 

 may be displaced, but cannot be squeezed into less compass, and which, being 

 forced towards the inner corner of the eye, drives before it that important and 

 beautiful mechanism the haw, so the elastic and yielding substance the frog, 

 being pressed upon by the navicular bone and the tendon, and the pastern, and 

 refusing to be condensed into less compass, forces itself out on either side of them, 

 and expands the lateral cartilages, which again, by their inherent elasticity, 

 recur to their former situation, when the frog no longer presses them outward. 

 It appears, that by a different mechanism, but both equally admirable, and 

 referable to the same principle, viz. that of elasticity, the expansion of the upper 

 and lower portions of the hoof are effected, the one by the descent of the sole, 

 the other by the compression and rising of the frog. 



It is this expansion upward, which contributes principally to the preservation 

 of the usefulness of the horse, when our destructive methods of shoeing are so 

 calculated to destroy the expansion beneath. In draught horses, from the long 

 continued as well as violent pressure on the frog, and from the frog on the carti- 

 lage, inflammation is occasionally produced, which terminates in the cartilages 

 being changed into bony matter. 



CHAPTER XIX. 

 THE DISEASES OF THE FOOT. 



OP these there is a long list. That will not be wondered at by those who 

 have duly considered the complicated structure of the foot, the duty it has to 

 perform, and the injuries to which it is exposed. It will be proper to commence 

 with that which is the cause of many other diseases of the foot, and connected 

 with almost all. 



INFLAMMATION OF THE FOOT, OR ACUTE FOUNDER. 

 The sensible laminae, or fleshy plates on the front and sides of the coffin- Done, 

 being replete with blood-vessels, are, like every other vascular part, liable to 

 inflammation, from its usual causes, and particularly from the violence with 

 which, in rapid and long-continued action, these parts are strained and bruised. 

 When in a severely contested race they have been stretched to their utmost, 

 while, at the fullest stride of the horse, his weight has been thrown on them 

 with destructive force : or, when the feet have been battered and bruised in a 

 hard day's journey, it will be no wonder if inflammation of the over-worked 

 parts should ensue, and the occurrence of it may probably be produced and the 

 disease aggravated by the too prevalent absurd mode of treating the animal. If 

 a horse that has been ridden or driven hard is suffered to stand in the cold, or if 

 his feet are washed and not speedily dried, Le is very likely to have " fever in 



