We must next apply another ligature round the penis behind the member, making the constriction at its extremity next the bladder, and then make an incision down upon the stone, and bending the penis we eject the stone, and undoing the ligatures we clear away the coagula from the wound. The posterior ligature is applied lest the calculus should retreat backwards, and the anterior, in order that, when untied, after the extraction of the stone, the skin of the prepuce may slide backwards and cover the incision. * * * * * COMMENTARY. We will now attempt to explain all the ancient descriptions of lithotomy. Hippocrates in his _Oath_ binds his pupils not to perform this operation, but to leave it to those who made it their business. It appears then that in his days lithotomy was a separate branch of the profession. Celsus is the earliest author who describes lithotomy, although it is probable that he merely explained the method of operating in Alexandria, the surgeons of which city had acquired great celebrity in performing this operation. He forbids the operation, except after every other remedy had failed; and in children between the ages of nine and fourteen, and in the season of spring. The patient is to be kept upon a spare diet beforehand; and when the operation is about to be performed, he is to be directed to walk, so as to bring down the stone to the neck of the bladder, which is to be ascertained by introducing a finger into the anus. Then a strong and experienced person, sitting on a high seat, is to take the patient and hold him secure, his buttocks being placed upon the assistant’s knee, and his legs being drawn in and his hands placed on them and held there. But if the patient be strong he is to be held by two assistants, one on each side, upon two seats placed beside one another, and they are to be directed to press upon his shoulders with their breasts, so as to force down the bladder. Two other assistants are to be at hand, to prevent any risk of the former two losing their hold. The surgeon having pared his nails, is to introduce gently first the index and then the middle finger into the anus, whilst with the right he makes pressure upon the abdomen, and in this way the stone is to be secured at the neck of the bladder. The shape of the stone is to be considered, and it is to be pressed down so as to favour its exit. These matters being properly arranged, a lunated incision is to be made over the neck of the bladder near the anus down to the neck of the bladder, the horns of the incision inclining a little towards the (left?) buttock; then at that part where the incision is bent round (at the curvature of the incision?) even under the skin, another transverse incision is to be made, by which the neck is to be opened, and the urinary passage dilated, the opening being somewhat larger than the stone. When the stone is small it may be propelled and drawn out by the fingers; but if large, it is to