The extensor muscles, of course, passing in a longitudinal direction on each side the superior part of the tail, from the spinal bone to the extremity, retains the power of raising the tail at pleasure; the flexors, running in a similar line at the inferior, or lower part, there possess a greater power of counteraction, and render the operation the more necessary, as, by diminishing the power of _one_, proportional strength is added to the _other_. Previous to the present expert and easy mode of operation, it was common to see the incisions (or nicks) the breadth of a very large finger, and a small one might be lodged in the cavity. These enormous chasms were made under an expectation of more _readily_ reaching the flexor muscle, which it was the intention to discover and divide; but which, in most cases, had been previously divided, and receded in the _first_ efforts; and sometimes, from the unnecessary destruction of parts, and profuse bleeding, produced alarm, followed by inflammation, frequently _danger_, and sometimes DEATH. This, however, is, as it ought to be, very much reformed, and not without a substantial reason, when it may be observed, that, upon raising the tail of a horse in its natural state, the two flexor muscles may be clearly seen, and distinctly felt, one on _each_ side the CENTRICAL bone, in common termed the DOCK, laying in a midway direction, between the bone and the edge of the tail where the hair begins. In performing this operation in a superior and masterly manner, the horse having been previously secured, (with hobbles and side-lines,) the tail is to be firmly grasped with the left hand, and turned up with considerable force towards the rump, when a superficial incision is to be made with a crooked pointed knife, directly over the seat of the flexor, which will be instantly perceived of a strong elastic texture, ready for separation by the knife, steadily held for that purpose; the tail being exceedingly firm in hand, by which the separated tendon will have the less power to recede. Immediately after the separation, the lower extremity having lost its elastic support, will be seen to hang full half an inch from the first incision; when a second, a third, and even a fourth, if necessary, is to be made in the same way on _each side_ the tail; it not being a matter at all requisite, that the skin in the middle, passing over the bone, should be divided, or that the wounds on each side should communicate with each other. The incisions being completed, the ends of the separated muscles should be secured with a pair of FORCEPS, or a curved NEEDLE, and when a little drawn out by moderate force, should then be taken off with a pair of scissars, or a knife, as close as they can be conveniently come at. It is a custom with some, to separate the tendon of each incision before they proceed to make another, and this seems to be the most rational and expeditious mode of the two.