The exposed position of this particular irregular bone, as it is classed anatomically, explains the frequency with which the surgeon is called on to treat it. Fractures of this bone are always due to some form of violence, or to the extraction of a tooth, the usual seat of fracture being the anterior part of the body of the bone, between the mental foramen and symphysis, which is obviously in the line of least resistance, although no part of the bone is free from the possibility of a fracture. The case to which I invite attention bears out this statement anatomically.
Patient.
—A very robust negro, aged about 30, an employee of the Seaboard Air Line Railway, blacksmith by trade, presented himself at my office not very long since. An hour before he had been struck with a sledge-hammer by a fellow workman on the right side of the chin.
Examination.
—Patient