The attendant, who had first put on the twitch, gives the stick to his companion, and lifts up one of the animal's legs. The horse, with its attention engrossed by the agony of its lip, is rendered disinclined to motion, and is comparatively powerless while standing on three legs. The surgeon then takes an abscess knife, not a lancet, which is a coarse and clumsy instrument--the lancet simply punctures, whereas in an abscess more is desirable. A free opening is always wished for; and where living flesh is to be operated upon, it is, for very many reasons, preferable to do all the cutting at once. The knife is held lightly in the hand, with the thumb resting on the back of the blade. The horse, when it feels the incision, is apt, spite of the twitch, to drag suddenly backward. Thus it pulls against the back of the knife, and no injury can occur; whereas, with a double-edged lancet, an ugly and a dangerous wound has, by the motion of the animal, been inflicted. The thumb, in this situation, also serves another purpose. It allows only so much of the blade to enter the abscess as is above the nail of the member--this is usually about three-quarters of an inch. The thickness of the skin, increased by disease, requires so much; and if not, the pus, accumulated beneath the skin, will save the more important parts from being injured. [Illustration: OPENING THE ABSCESS OF STRANGLES.] The leg being raised and the head guided upward by the elevation of the twitch, the operator approaches the horse. He looks well at the part he has to open, and mentally determines where to make his incision. He also ascertains the extent of the tumor. This is necessary; for if the swelling be to one side, a single incision will be sufficient; but if this extend (as is usually the case) from right to left, two incisions are requisite. In either case the surgeon seizes the left rein with the left hand, and, placing his right hand in a proper position, by a short and simple motion of the wrist the knife is driven through the skin. The horse, during every operation, is usually blinded. Darkness invariably increases terror, and is unnecessary, since the horse cannot see what is being done under its jaw; nevertheless, the creature is obviously amused by watching the people about it. From the behavior, we have no reason to imagine the animal draws any conclusions. To blind the horse is, therefore, to increase to fears of excessive timidity. It is easily accomplished. Double a handkerchief into close longitudinal folds; then tie either end to the sides of the bridle, so that the handkerchief may rest upon the eyes, and the object is attained.