TOE SANDCRACK. 481 



the iron, beginning at the coronet with either extremity of the 

 segment, and bringing the firing to a finish at the centre. The 

 iron should be at a strong red heat, and be carried through 

 the horny crust until it touches, lightly, the sensible laminae, and 

 so throughout the entire semicircle. As you recede from the coro- 

 ^ net, so in proportion you will require to deepen the fissure in the 

 crust. The iron ought to be re-applied every week or ten days. 

 The first effect desirable to be produced is a bulging of the crust 

 around the coronet within the segment; and when once this 

 is fairly established, the cure may be said to be effected, it 

 being seldom necessary to apply the cautery afterwards. The 

 old method of making a line with the iron across the fissure 

 cannot prevent the opening and closure of the fissure during the 

 action of the foot ; whereas, isolating the fissure (or part of it) 

 within the segment of a circle, completely effects the object. No 

 tar-cord or strapping or alteration of the shoe is required to limit 

 the motion of the crust, all motion being suspended within the 

 segment, and especially after bulging has commenced. The sub- 

 joined woodcut will explain the old and new method of ope- 

 rating with the firing iron. 



b 



a a A sandcrack intersected at d d Toy transverse firings. 



b b A sandcrack isolated (in part) at c by semi-circular firing / /. 



The Objects of Treatment, after what has been stated, 

 will clearly appear to be — first, to place the hoof in such a con- 

 dition as shall not render it liable to crack afresh ; secondly, to 

 remove that state of it which, in the first instance, disposed it to 

 crack, if it were not of itself the immediate cause of the crack- 

 ing. The way in which the first object is to be effected has 

 been already shewn ; and when this has become accomplished, 

 past all risk of return, we may set about to bring into effect the 



VOL. IV. 3 Q 



