474 QUARTER SANDCRACK. 



of the hoof; but in these two situations it is that veritable sand- 

 crack occurs, and there are here, as we shall find hereafter, 

 special causes for their production. Let us first consider 



Quarter Sandcrack. 



The Situation of this Crack is the slanting line of 

 the wall of the hoof, directly opposed to the extremity of the 

 ala of the coffin bone ; and it is oftener found in the inner than 

 in the outer quarter. Added to which, the hoof in which such 

 crack occurs is always a contracted one : quarter sandcrack, no 

 more than toe sandcrack, never happening in a hoof disposed to 

 openness and flatness. The same description of horse and foot 

 which is predisposed to contraction is for the same reasons pre- 

 disposed to sandcrack. There is an obvious connexion between 

 contraction and quarter sandcrack. The light, near-the-ground 

 stepping horse, with strong, narrow, upright hoofs, will be equally 

 likely, under certain conditions, to have the heels of his fore 

 hoofs becoming contracted, and exhibiting quarter sandcracks. 

 Hot stables conduce to this; but more still hot climates. 

 Hurtrel D'Arboval informs us, that at the time the French army 

 were in Egypt their horses were continually having sandcracks ; 

 and he adds, that long voyages on board of ship are on occasions 

 attended with like results. 



The proximate Cause of Quarter Sandcrack is, 

 then, contraction. The horn, from dryness or other cause 

 rendered cracky and fragile, breaks at the quarter of the wall, 

 from being at that part bent across the edge of the ala of the 

 coffin bone, during the curving in of the heel, the result of con- 

 traction ; and this oftenest happens to the inner quarter, from 

 its being the thinner and weaker one, as well as from being the 

 one which is the first and most disposed to contract. Not that 

 sandcrack is the necessary consequence of contraction ; but that 

 contraction becomes a necessary precursor to sandcrack. If this 

 were not the explanation of the case, sandcrack would be 

 as likely to occur in any part of the wall as at the quarter, 

 and on the outer as often as on the inner side of the wall. This 



