Amongst these are classed in the first place, various incised, punctured, and shot wounds, contusions, and lacerations of the brain: the latter are produced partly by the instrument with which the injury is inflicted, and partly by the splinters of bone which are depressed or driven in; and partly they are independent of both these causes, and are the result of the violent concussion which the skull has sustained. They are found most commonly at the seat of the injury, but sometimes at other distant points also, deep in the brain, or as is more frequently the case, just opposite the injured spot; and sometimes they exist at several of these points together. The condition of the brain at these parts, varies according to the amount of the injury: either there is no perceptible solution of continuity, but the brain is more or less suffused, that is, sprinkled with red dots and streaks of extrava-sated blood (capillary apoplexy), and uniformly tinged also of a deep red color with blood; or it is distinctly ruptured, and the intervals are filled with extravasated blood; at other times, the cerebral substance is bruised to a uniform pulp, and of a paler or a darker red color, according to the quantity of blood extravasated into it.

Moreover in sanguineous apoplexy, the brain undergoes spontaneously a laceration, a breaking down, a concussion, exactly similar to that produced by mechanical injury. In the higher degrees of dropsy of the ventricles, as I have already mentioned, the septum may be perforated, the soft commissure torn, etc.; and in some rare cases (see p. 276) the cerebral substance around the ventricles bursts, and the serum escapes.

Incised and punctured wounds, when slight and clean, sometimes heal by adhesion; and the slighter cases of contusion are repaired in the same manner as hemorrhage in the brain; but more extensive injuries give rise to greater degrees of inflammation, to suppuration, and yellow softening, and sooner or later destroy life. Wounds from which loss of substance ensues, heal by granulation, which fills up the cavity, and adheres to the cicatrix that supplies the place of the cerebral membranes and bone. And in this case, the space within the skull is also partly filled up by an enlargement of the ventricle of the same side, proportioned to the quantity of substance lost, and to the difficulty of replacing it with granulation and cicatrix. Sometimes the granulation is exuberant, and grows up to, and beyond the opening in the skull, presenting a condition long known to surgeons by the names of fungus cerebri, and hernia cerebri.

There is one case which calls for especial remark in this place, namely that of concussion, without any perceptible lesion of the continuity of the brain. It results from a fall from a height, and is usually combined with extensive shattering of the skull. It is rapidly fatal; and after death the brain is frequently, though not always, found manifestly collapsed and bloodless. But it may also be produced by force applied to a circumscribed portion of the skull. A solution of continuity, often inconsiderable, then ensues in the skull, a small extravasation occurs over or under the dura mater, and subsequently inflammation, necrosis of the bone, and inflammation and suppuration of the dura mater take place at the injured spot. These are not unfrequently preliminaries of a diffused inflammation of the pia mater (meningitis); though sometimes the meningitis comes on without such antecedent. But the gravest of all are those rarer cases in which, not only without any of these occurrences in the neighborhood of the brain, or perceptible lesion of its continuity, but even, without the slightest subsequent alteration of its structure that can be detected, an affection of the brain supervenes, either immediately upon the injury or some time after, and proves fatal. In some cases of this kind, which are well known to distinguished surgeons, as well as in others in which the violence inflicted was attended with palpable structural disease of the brain, I have observed not only a remarkable emaciation of the whole body, but more especially a very rapid disappearance of the mass of the blood (anaemia), which was the more conspicuous from the previously full habit of the patient.