from off the frog occasionally, it becomes pu- 

 trid, and dissolving the surface where it chiefly ' 

 accumulates, produces what is called a running 

 thrush, which leads to the destruction of the part. 

 And as when the frog is ulcerated and rotten, 

 it can scarcely afford such resistance as is ne- 

 cessary to keep the heels at their original dis- 

 tance, even when the crust rests on a flat surface, 

 it necessarily gives way more rapidly than a 

 sound frog to the pressure of the weight of the 

 body, forcing the heels towards each other down 

 the sloping surface of the shoe in common use. 

 In consequence, likewise, of the heels being thus 

 raised, the weight is thrown forwards upon the 

 toe, the knees are weakened, and the fetlock joints 

 are strained. 



From the improved state of the roads, caulk- 

 ings have gradually become less general, and, 

 at present, two on each shoe are used for heavy 

 draught horses alone; for the lighter kind, one 

 on each shoe is employed; whilst for saddle 

 horses, which are intended to be worked on the 

 readonly, caulkings are scarcely ever made use 

 of, and in fact are never necessary, unless, per- 

 haps, in frosty weather. 



But although it has been fully ascertained, 

 that horses may be hunted with safety in some 

 countries without caulkings, yet it is always safer 



