356 DADDS VETERINARY MEDICINE AND SURGERY. 



terminates in exostosis, coated with some tissue very imperfectly 

 representing the original laminated structure. 



Mr. Braby, the intelligent veterinary surgeon to Messrs. Bar- 

 clay and Perkins' establishment, to whom I am indebted for much 

 of the information I possess on this part of my subject, has had 

 many cases of this description, one of which, of extraordinary char- 

 acter, I shall relate here. One of his dray hordes had suffered long 

 and severely from toe sand-crack in one hind foot, but, at length, 

 had recovered, and returned to work. Some time afterward, how- 

 ever, during the season of influenza, he was attacked with a vio- 

 lent laryngitis, which increased to a degree to call for the operation 

 of tracheotomy, to save him from suffocation. Notwithstanding 

 this temporary salvation, however, the patient, in the end, suc- 

 cumbed to the disease. His post-mortem examination became 

 doubly attractive, owing to the circumstance of the long-standing 

 and obstinate sand-crack he had suffered from heretofore, and the 

 result in this latter respect proved extremely interesting. The 

 coffin bone, along its front, occupying the line of the surface be- 

 tween the coronal process and the toe, exhibited a channel or loss 

 of substance half an inch in breadth, and fully the same in depth, 

 thereby robbing it of a quarter of an inch of its solid diameter. 

 This, of course, left the bone considerably weakened, the result of 

 which subsequently was, transverse fracture in two places, the 

 fractures commencing upon the articulatory surface, whence they 

 extended directly crosswise through the middle of its body, so as 

 to become apparent upon its concave surface underneath. In 

 addition to this, growing from the laminated interior of the wall 

 of the hoof, opposite to the middle or deepest part of the channel 

 in the coffin bone, was a projection of hard, horny, callous sub- 

 stance, having a covering of imperfectly-formed horny lamin:B. 

 At the time this horse was suffering in the greatest degree from 

 this extraordinary product of sand-crack, constitutional irritation 

 ran so high as even to create alarm for the animal's life. The 

 treatment of sand-crack, whether it be in the quarter or in the toe, 

 will have to be conducted upon principles applicable to both fornix 

 of the disease, though one must be regarded as of much more con- 

 sequence than the other. The treatment of quarter sand-crack, 

 generally speaking, is but comparatively a simple affair; indeed, 

 so lightly is it looked upon by horsemen in general, that we should 

 run some risk of their displeasure, and our own reputation as 



