DISEASES FROM FAULTY CONFORMATION 171 



means the crack prevented from becoming longer. Very 

 often this is all that is necessary. In fact, we may say 

 here that, no matter what other treatment is adopted, the 

 simultaneous application of a blister to the coronet is 

 always beneficial. To derive full advantages therefrom, 

 the blistering should be repeated several times at intervals 

 of about a fortnight. 



(b) Clamping the Crock. — When the services of a skilled 

 smith are at hand, one of the readiest methods of perform- 

 ing this is to draw the edges of the crack together with an 

 ordinary horse-nail. 



On each side of the crack a small horizontal furrow is 

 burned or cut into the wall, leaving the horn for about 

 I inch on each side of the crack intact. This provides a 

 groove for the ends of the clamping-nail to rest in, and 

 brings them flush with the outer surface of the wall. The 

 nail is then driven carefully home through the crack, and 



Fig. 86. — The Sand-crack Firing-Iron. 



the pointed end grasped by the farrier's pincers. The edges 

 of the crack are then drawn tightly together and the nail 

 firmly clenched. 



' The horse-nails are prepared in the ordinary way as for 

 driving, with the exception that each is pointed on the 

 reverse side, to prevent puncturing the sensitive structures. 

 Before being used the nails are put in a vice, and the head 

 hammered to form a shoulder, to prevent their being driven 

 too far into the wall, and breaking out the hold.'" 



Before driving the nail some operators burn or bore a 

 hole for it. Opinion seems to differ as to whether this is 

 at all necessary. 



A method of clamping which, on account of its simplicity, 

 has become greatly popular, is that of Yachette. For this 

 operation is needed the outfit depicted in Figs. 86 and $7. 



* Veterinarian, vol. xlviii., p. 100. 



