180 



])ISEASES OF THE FEET. 



be made independently of the downward extent of the fissure; for 

 the object is to isolate, from the effects of concussion, that pre- 

 sumably weak portion of the coronet which is immediately above 

 the crack, and has to secrete new, sound horn in place of the broken 

 liorn ; and, also, to prevent motion between the divided edges close 

 to the upper extremity of the fissure. It is well to pare away as 

 far as piracticable the two pieces of isolated horn which are within 

 the V ; for their presence may cause irritation. 



If the craok extends below the point of meeting of the two 

 grooves, a third groove may be out across its lower end. 



The grooves should be first made by burning through the hard 

 outer layer of horn witli a narrow and curved red hot iron (Fig. 



Fig. 54. — (Operation for sandcrack. 



55), so as to mark out the way for the searcher, and to prevent 

 tlie horn splitting. 



The French method of rhi^i'ing is performed by heating the 

 points of the instrument A (Fig. 56), and then by burning lioles in 

 the hoof with them at equal distances from, and at opposite sides of, 

 the crack. The ends of the clasp B are now fitted into the holes 

 made by A, and the clasji is tightened by a powerful pincers, made 

 tor the purpose, in order to bring the edges of the fissure closely 

 together. This is an easy operation. The holes should be made 

 very narrow, so that the points of the clasps will have to be forced 

 into them ; the horn should be allowed to cool down completely 

 liefore the clasps are put in ; it is advisable to use as many clasps 

 as there is room for them, the clasps being placed alxjut two-fifths 



