Scull, is a conjunction of bones, eight in number, surrounded by a membrane called the pericranium, and forming a cavity for the brain ; which is thus completely inclosed and defended. - In an infantile state, the scull is of so delicate a texture, as to admit of being moulded into almost any form; a circumstance, on which the shape of the heads of different nations chiefly depends ; but, in an adult state, they acquire so concrete a form, as to represent one solid bone, and are afterwards more easily broken than separated. - The edges or margins of the bones are distinguished by certain lines, called sutures.

The principal injuries, to which the scull is exposed, proceed from external violence; for instance, blows and falls, by which the bones may be fractured. The danger attending such accidents, varies according to the more or less complicated nature of the fracture, and the relative health of the patient: for, if his constitution be debilitated, or the humours be vitiated, the most trivial contusion of the head may prove fatal.

The symptoms, by which a fracture of the scull may be ascertained, are as follows : the points of the bones may sometimes be felt ; the patient is afflicted with giddiness, drowsiness, stupefaction, loss of sight; and, when the concussion has been violent, blood is discharged from the eyes, nose, and ears; which last circumstance generally denotes a compression of the brain. If, however, several of these appearances concur, and the diseased part cannot be distinguished, the head should be deliberately, but firmly pressed in every direction ; thus, the patient will, in most instances, point out the seat of the injury, by his own sensations of pain or uneasiness, when the fractured part is touched.

As these dangerous cases require the application of the trepan, without delay, we shall only state a few particulars relative to the dietetic treatment, after the operation is performed. The patient ought to be kept in the most quiescent state; his bowels must be regulated by gentle aperients, such as are the most agreeable to the taste and stomach, in order to avoid vomiting ; the food should consist of the lightest and most digestible vegetables; while be must cautiously abstain from all fermented and spirituous liquors, and drink barley-water, or other diluents, in which a few grains of nitre have been dissolved.

A small scar generally remains after the wound is healed ; but, if a considerable part of the integuments have been lacerated, or de-stroyed, the bone will be covered only by a thin skin, over which the convalescent ought to wear a round plate of tin or silver, adapted to the purpose, and lined with flannel, to protect it from external injury.