A middle-aged man was brought intoxicated into the Royal Infirmary with a lacerated wound of the scalp, over the upper part of the occipital bone, on the _right_ side of the mesial line. For thirteen days after the accident he did well, walking about the wards in good health, with the wound healing kindly; but on the fourteenth he became affected with hot skin, restlessness, slight incoherency, severe pain in the head, and intolerance of light, with a full but not quick pulse. A vein was opened, but after three ounces of blood had flowed, he was seized with rigors, vomiting, and violent convulsions; and these symptoms again occurred after the application of leeches to the head. Rigors returned at various intervals; stupor supervened and gradually increased. He became delirious on the eighteenth. A considerable part of the bone was exposed and dead, and there was a puffy swelling of the scalp around the wound. On the nineteenth he lay insensible. A portion of the dead bone was removed by the trephine, and the dura mater was found covered with lymph, but no appearance of effused blood or pus could be perceived. He seemed to suffer nothing from the operation, but continued insensible, passing his urine and feces in bed, with dilated pupils, quick breathing, and subsultus tendinum; his pulse, which had previously never been above 80, now rose to 100. He died on the morning after the operation. On dissection, the right hemisphere of the brain was found of the healthy appearance; but four ounces of pus lay over the _left_ hemisphere, between the dura mater and arachnoid, which latter membrane was of a granular appearance; there was also a small sloughy spot of the dura mater over the left anterior lobe.—A woman, aged 40, fell down and sustained a wound of the scalp on the upper part of the occipital bone on the left side; she suffered but little from the accident, and continued to live freely and irregularly. Seven days after the injury she was seized with shivering: and on the ninth day she lay comatose, voiding her feces and urine involuntarily. The wound was pale and gleety, and the surrounding scalp puffy; the bone was bare and white; pupils dilated; pulse slow. The trephine was applied, and fluctuation felt beneath the exposed dura mater, which was otherwise unchanged in appearance; the membrane was divided by a trifling crucial incision, but only a small quantity of bloody serum escaped. Shortly after the operation she became quite sensible, but again sunk into a state of stupor, with slightly stertorous breathing and contracted pupils. However, all traces of coma disappeared next day, and she recovered soon and perfectly, apparently without having received either benefit or injury from the operation of trephine.