The horn is itself a secretion, and, in a healthy state, is intimately united with the source of its origin. When, however, pus is effused, this always lies between the secreting membrane and the horn, which has been already secreted. The horn so displaced by the presence of a foreign substance is called under-run or detached; and all horn, so under-run or detached, must be removed. When this operation is properly performed, all signs of lameness will have generally disappeared. It is usual, however, to tack the old shoe on again; and having dressed the injury with chloride of zinc and water--one grain to the ounce--there remains only to examine the foot from time to time till new horn covers the surface; merely taking precaution for the present to shield the wound with a little tow, fastened in its place by a couple of cross splints. When sanguineous or sappy corns are found, the method is, firstly to thin the sole, so as to render it pliable, especially over the seat of corn. Should a sappy corn have rendered the horn moist for any space, or should the discoloration caused by sanguineous corn be of any size, it is as well always to open the center of the part indicated: no matter should the cut release only a small quantity of serum or a little blood. Take away a small portion of horn; pare the sole till it yield to the pressure of the thumb. When such a proceeding is necessary, the bars may be entirely removed, and the wounds should be covered with some tar spread upon a pledget of fine tow. As soon as the orifice is protected by new horn, the horse may be shod with a leathern sole and returned to its proprietor. Such a course would occupy little time--a week at most. Yet the great majority of horse proprietors appear to have "flinty hearts," as nearly all of them begrudge the necessary day of rest to the maimed animal which has been injured in their employment. The cry, where the horse is concerned, is "toil, toil!" The veterinary surgeon is often asked "if _absolute_ rest is imperative." He is frequently solicited to patch up the poor animal, so that it may do a _little_ work. As day after day passes onward, the tone becomes more and more authoritative. The horse is at last too often demanded from the hospital, and taken to resume ordinary labor before the injury is effaced. Should no evil effect ensue on such a culpable want of caution, the proprietor is apt to chuckle over his daring with another's sufferings, and to blame the science which would not incur risk, even to propitiate an employer. [Illustration: THE POSTERIOR OF A HORSE'S FOOT SHOD WITH LEATHER. The central angular mark indicates the place into which the liquid stopping should be poured. ]