_Inflammation of the Scalp_ occurs either spontaneously, or in consequence of external injury, though slight; and is generally met with in those who have lived freely and irregularly, and are of a bad habit of body. It is more dangerous than inflammation of any other part of the surface, on account of the sympathy and connection which exists between the parts affected and those situated internally: frequently, at an early stage of the affection, delirium occurs, with violent fever. In slight cases, in which the external surface merely is affected, there is little swelling, and but little pain or fever. But when all the pericranial coverings are involved, the symptoms are uniformly severe. The swelling is elevated and puffy, and extends to the eyelids, to the face, and, in some cases, even to the neck: the constitutional symptoms run high, and there is considerable risk of the patient dying comatose. If he recover, and if the disease is little interfered with, but allowed to take its own course, much sero-purulent fluid is infiltrated into the cellular tissue, which generally perishes, along with a greater or less portion of the tendinous expansion lost by sloughing. Often, in neglected cases, a large abscess forms, separating perhaps one-half of the scalp, and bulging over the ear. The constitutional treatment must vary according to the nature of the symptoms which present themselves; in some cases they show great vascular excitement, and in others they bear unequivocal evidence of general debility from the first. In slight cases of the local affection, it is sufficient to relieve the tension, and abstract blood and effused serum by means of a few punctures, and afterwards to use warm fomentation. More violent cases require free incision in the direction of the fibres of the occipito-frontalis muscle, and thus only can destruction of the parts be averted; the incision must necessarily be deep, for the scalp is often swollen to the thickness of one or more inches. When a depôt of matter has formed, it must be evacuated early, otherwise there is a risk of the bone becoming extensively denuded and exfoliation ensuing.