_Operation._--The patient lies on his back, with his head and shoulders slightly raised, so as to relax the abdominal muscles, and his legs hanging down over the edge of the table. If his bladder can bear it, it should be fully distended, either by voluntary retention of the urine, or by injection with tepid water. A vertical incision is then made in the middle line, separating the recti muscles from below upwards, care being taken to push the peritoneum well out of the way, which is easily done by the finger in the loose cellular tissue of the part. The anterior wall of the bladder is then exposed, uncovered by peritoneum; it must be opened with great care, also in the middle line, while the wound in the parietes is held aside by retractors. The wall of the bladder should be transfixed by a curved needle, and thus held in position before it is opened. The stone is then removed by a pair of straight forceps, generally with great ease. Attempts used to be made to leave a catheter or canula in the bladder wound to prevent infiltration. Probably the safest method now will be to close the bladder wound at once by metallic stitches, and stitching the abdominal wound carefully with deeply entered wires, to leave the patient on his back. When compared with the lateral operations the statistics of the supra-pubic operation are discouraging, the mortality being one in three and a half to one in four. But in cases where the stone is known to be very large and of firm consistence, the risks are probably less from this method than from lateral lithotomy, followed by efforts to crush the stone through the wound prior to its removal. The late Mr. George Bell, a most successful lithotomist, proposed to perform this operation in two stages. In a case of greatly enlarged prostate, where the bladder had been punctured above the pubes by a country surgeon for retention of urine, he dilated the track of the canula by means of sponge-tents gradually increased in size, and then succeeded in extracting through the dilated opening several large calculi. The case recovered, and may encourage similar attempts. 3. OPERATIONS THROUGH THE RECTUM.--(_a._) _Sanson's Recto-vesical Operation._--The principle of this operation consisted in laying the two canals, the rectum and the urethra, into one. A large staff, grooved on its convexity, being inserted into the urethra, the operator, with the forefinger of his left hand in the rectum as a guide to the knife, pierces the anterior wall of the rectum, reaches the groove of the staff just in front of the prostate, and cutting outwards divides the rectum, the anterior fibres of levator ani, and the sphincter, as well as the skin of the perineum in the middle line. Entering the knife again into the groove of the staff, it is to be pushed right onwards into the bladder, dividing the prostate, and avoiding if possible the seminal vesicles and ducts; the stone is then very easily removed.