622 OPERATIONS ON THE FOOT. 



It lias been supposed that this could be done with the putty of 

 Defay's, a mixture of gutta-percha (2 parts) and gum ammoniac 

 (1 part), introduced into the well-cleaned fissure, and pushed in as 

 deeply as jiossible by a warm iron plate or a spatula. This putty 

 is excellent for superficial cracks, but is insufficient to bring the 

 borders together when the fissure is somewhat deep, or especially 

 if it is irregular and sinuous. 



A better way, at least for toe crack, is that which consists in 

 suturing the edges of the solution of continuity by metallic clasps, 

 which immobilize the hoof. This mode is always preferable to 

 circular liga*tures of wire or cord, which have the efi'ect of interfer- 

 ing with the natural elasticity of the hoof. Clasps only fix the 

 hoof locally, and are an old means of treatment, having been used 

 by Sollej^sel and Garsault. 



It was advised to perforate the horn through and through with 

 a small punch, and pass a wire, which was bent over the crack, or 

 twisted together at the ends. The same authority recommends 

 the dri\ing of a nail through both edges, and securing it tightly, 

 as in the application of the nails of the shoe. This treatment was 

 recently recommended by Haupt, Lafosse and Rey. The first of 

 these professors takes an ordinary nail, with a small head, drives 

 it through one edge of the crack, so as to come through the other 

 at an equal distance from the point of entrance ; the nail being 

 thus driven to the head the borders of the crack are then brought 

 together, and the nail secured in the ordinary way. Two or three 

 of these clasps are employed, according to the extent of the crack. 

 Lafosse makes a groove on each side of the fissure about one centi- 

 meter from the border, in a direction transverse to that of the 

 fibres of the wall, which limits the passage of the nail. The nail 

 is then introduced and secured as in the first instance. Eey 

 makes a track for the nail first, by drilling a hole through the 

 borders of the crack. The animal must be cast diu'ing these 

 operations. 



The best kind of clasps or hooks are undoubtedly those of 

 Vachette, which require sj^ecial instruments for their application, 

 but give a real solidity to the means of fixing the position of the 

 parts. The clasjDS are all prepared, made of strong wire, bent at 

 both extremities, and slightly sharp inwardly (Fig. 489). These 

 are secured on the foot by a special nipi^er or forceps (Fig. 490) 

 in the notches made on the wall with a special cautery (Fig. 491) ; 



