which rolled down a precipitous bank, and struck him on the vertex. He lay insensible for half an hour, but recovered, and followed his occupation during the rest of the day. In the evening he came for advice. There was a small wound in the scalp, and the subjacent bone was fractured exactly in the same manner as in the former instance, but he felt no uneasy symptoms whatever. The consequences likely to result from such an injury, and the necessity for trephining, were represented to him; he agreed, and the operation was performed on the spot. Many sharp fragments of the inner table were extracted; he proceeded home, never had a bad symptom afterwards, and consequently required no treatment save dressing of the wound. The operation, if undertaken early, will, in all probability succeed in averting future evil, more especially if the dura mater be not wounded. As a proof of the unfavourable nature of this latter circumstance, I give the following case:—A young man, aged 18, received a kick on the forehead from a horse, September 9th. He remained perfectly sensible, and did not fall to the ground. Shortly after, he was seized with vomiting, which recurred at intervals; his pulse was regular, but feeble; pupils dilated. On the centre of the forehead, there was an irregular wound, which extended to the root of the nose; and on introducing the finger, the os frontis was found fractured, and a small portion of it comminuted and depressed. The trephine was applied, and several detached portions were removed, with some difficulty, from beneath the undepressed portion of the bone. A spiculum had lacerated the dura mater, and penetrated the substance of the brain, to the depth of half an inch; on removing it, a small portion of cerebral matter escaped. The fracture extended apparently in the direction of the right orbit. In the afternoon, the pulse was sixty-four, of good strength, and the pain in the wound had slightly increased. He was bled to fourteen ounces, and ordered an antimonial solution. Afterwards, the pain of the head increased, the pulse rose, the scalp around the wound became the seat of puffy swelling, and several small abscesses formed: the antiphlogistic regimen was rigorously followed, and the abscesses were freely opened as soon as they began to form. On the 21st, a portion of the brain had sloughed, and there was some appearance of fungus cerebri; an incision was made into a swelling over the right temporal muscle, and ℥viii. of blood allowed to flow. On the 22d, several portions of brain were discharged, the pulse was 100, and intermitting. Next day, he was delirious, and a hernia cerebri protruded, of sloughy appearance, and considerable size; pulse 142. Soon afterwards he became comatose; and died early in the morning of the 23d. On dissection, the integuments and pericranium surrounding the aperture, in the frontal bone, were found much thickened, and infiltrated with pus and serum. The dura mater at the wound had a