SHOEING. 35 



utility mainly depending on the texture and arrangement 

 of the horny matter of which it is composed, and the 

 peculiar disposition of this in fibres of variable density, 

 size, and elasticity. 



But these qualities of the hoof, it was again remarked, 

 are intimately dependent upon the manner in which the 

 horn-secreting surface performed its office ; as if this be- 

 comes diminished, weakened, or unable to supply suffi- 

 cient material to compensate for undue wear, the protect- 

 ing case soon ceases to guard the living tissues within 

 from injury. 



In a natural state, when the equilibrium between 

 growth and wear is destroyed, and the latter takes place 

 in a rapid and unusual manner, the animal is compelled to 

 rest until the worn hoof has recovered its proper thick- 

 ness ; for acute pain results when the living parts are ex- 

 posed, or when the wasted horn is insufficient to guard 

 them against being bruised by the ground. 



In an artificial condition, when the horse is employed 

 on hard roads, broken ground, and in a humid climate, to 

 carry and draw heavy loads at different degrees of ve- 

 locity, and forced to stand on stony pavements during 

 resting hours, his hoofs are unable to meet the many se- 

 vere demands imposed upon them. 



The wear more than counterbalances the growth ; and, 

 therefore, it becomes an absolute necessity, if the animal is 

 to be continuously and profitably utilized, that an artifi- 

 cial protection, sufficient to meet the exigencies of the 

 case, be employed. 



The lower border of the wall ig, as we have mentioned, 

 the part most deeply concerned in resisting wear and 

 strain in the unshod state, as on it the stress chiefly falls ; 

 it is, consequently, the portion of tub hoof that suffers 

 most severely from undue wear, and that which alone re- 

 quires protection. 



