The swelling of the scalp is often general, and is slightly œdematous; some points are more elevated than others, feel soft, and are the seat of extreme pain when pressed upon. But such affections frequently flit from one part to another; what was most unsound, at one time, recovering itself, and painful swellings attacking that which was comparatively free of disease. The same holds true in regard to the other bones at the commencement of the affection; but when much change of structure takes place, then the pain and swelling become fixed. The pains are most severe during the night, being then so violent as to deprive the patient of rest, and even prevent him from placing his head on the pillow: they abate towards morning, and remain tolerable during the day. They are always aggravated by change in the atmosphere from dryness to moisture, and the prevalence of easterly winds is peculiarly distressing to patients afflicted with such diseases. The swelling is composed of thickened and vascular periosteum with œdematous integuments. The bone too is often increased in size, and condensed, from continuance of increased vascular action; and its surface is roughened in consequence of its texture being opened out, and new bone having been deposited. Death of portions of the bone often follows, either spontaneously, or after slight bruises received during the continuance of the disease. A few accidental blows on the head, and a perseverance in the use of mercurial alteratives for a series of years, gave rise to the state of matters represented in the accompanying illustrations. The large dead portion represented was removed some months before death. Here the deficiency in the cranial bones is partly owing to ulceration, partly to death of portions of them. The patient’s health becomes undermined by want of sleep and continual suffering; and he may at the same time have relaxation of the mucous surfaces, with increased discharge from them, produced by the same cause as occasioned the affection of the coverings of the bones. He may be subject to a relaxed or ulcerated state of the throat, increased or caused by the slightest exposure; and may have hemorrhage from the nostrils, copious expectoration, mucous stools, &c. The periosteal affection alone is a troublesome and serious complaint. [Illustration] [Illustration]