able elasticity ; the cleft oval, oj^en, and expanding, with a 

 continuous, well defined, and somewhat elevated boundaiy ; the 

 bulbs at the heels fully developed, plump, and rounded ; and 

 the whole mass occupying about one-sixth of the circum- 

 ference of the foot* By degrees the fulness and elasticity 

 will be observed to have diminished ; the bulbs at the heels 

 will shrink, and lose their plumpness ; the cleft will become 

 narrower ; its oval form disappear ; the back part of its 

 boundary give way ; and it will dwindle into a narrow crack, 

 extended back between the wasted, or perhaps obhterated 

 bulbs, presenting only the miserable remains of a frog, such 

 as may be seen in the feet of most horses, long accustomed 

 to be shod. 



The bones, proper to the foot, are three in number, viz. the 

 coffin bone, the navicular bone, and pai't of the coronet bone ; 

 they are contained within the hoof, and combine to form the 

 coffin joint ;t but the smallest of them, the navicular bone, 

 is of far more importance, as connected with our subject of 

 shoeing, than either of the others ; for upon the healthy 

 condition of this bone, and the jomt formed between it and 

 the tendon, which passes under it to the coffin bone, and 

 is called the navicular joint, mainly depends the usefulness 

 of the horse to man. 



This small bone,| which in a horse sixteen hands high 

 measures only two and a quarter inches in its longer diameter, 

 three fourths of an inch at the widest part of its shorter 

 diametei', and half an inch in thickness in the centre, its 

 thickest part, has the upper and under surfaces and part of 

 * Plate 1, fi-. 1. t Plate 2, fig. 4. J Plate 2, fig. 3. 



