DISEASES. 609 



the hoof." Without shoeing there would be no corns, and it is in 

 its irrational methods that the true causes of these accidents 

 originate. It is by the greater or less frequency of corns that one 

 may judge of the state of that art in a country. 



The faults are found, 1st, in the manner in which the foot is 

 pared, or in the shape which it receives ; 2d, in the fitting of the 

 shoe ; 3d, in its appHcation. In paring the foot, the sole is often 

 weakened and thinned too much ; it does not resist the pressure, 

 and, at the time of resting the foot, all the weight of the body is 

 thrown upon the point of union of the sole with the wall. Ordi- 

 narily too much has been cut away from the frog, and this not 

 resting any more on the ground, no longer resists the pressure, 

 and the lowering of the branches of the sole is then extreme, as 

 proved by the experiments of Leisering. The custom of cutting 

 the corns, and of cutting the hoof at the heels, acts in a similar 

 manner ; the posterior half of the foot is weakened, and that is 

 the part which must carry the greatest part of the w^eight. One 

 needs only to compare a foot from which the shoer has removed 

 much horn at the sole, frog and bars, with one in which the hoof 

 has been left alone for a long time. In making a vertical and 

 tranverse section of the two in the middle of the frog, a little in 

 front of the angles of the sole, he will see at once how weak the 

 point of reunion of the sole with the wall has become, the means 

 of resistance to the pressure of the weight of the body through 

 the thii'd phalanx being thus diminished, and consequently a pre- 

 disposition to bruises created. 



The shape of the shoe also contributes to corns ; an excess of 

 concavity ; a shoe which from the last nail-hole is not flat to the 

 heels, whose branches are too much inchned, contributes to the 

 lateral contraction of the foot and gives rise to corns. In this case 

 the shoe resists the play of the horny box, and by itself, through 

 the sole, exercises a' great pressure upon the tissues underneath. 

 Too high caulks, in preventing the resting on the frog, cause an 

 excessive pressure on the inside of the foot, and compel it to rest 

 on the heels and the branches of the sole, which are too much 

 lowered. The opposite excess, when the shoe is thin at the heels, 

 as in the Coleman shoe — which is thick at the toe and thin at the 

 heels — produces a similar result, because in increasing the pres- 

 sure on the heels, it gives rise to bruises of the tissues through 

 the retrossal processes, which comes down too heavily. A very 



