From the _Commentary of the Four Masters_ we learn that Salernian practitioners recognized the diagnostic importance of nausea, vomiting, and the flow of blood from the ears in injuries to the head; that they resorted to the trepan for depressed fractures and the relief of intracranial extravasation; that hernia cerebri was treated by pressure and caustics; that ligatures, both above and below the opening, were applied for the treatment of wounds of the carotid arteries and jugular veins. It was advised to decline patients suffering from wounds of the heart, lungs, diaphragm, stomach, or liver, in order to avoid the disgrace of losing them; and in penetrating wounds of the intestines and in those complicated with protrusion of the wounded gut instruction was given how to envelop them in the warm abdomen of a slaughtered animal until natural color and temperature were restored, and then to insert a cannula of alder-wood into the wounded intestine, which was to be neatly closed and stitched; finally, the protrusion was to be carefully washed with warm water and returned into the abdominal cavity, enlarging the opening for this purpose, if necessary. Also was advised the extraction of diseased teeth; and the operation of lithotomy was described with considerable care. Compound fractures were to be treated with splints. On the whole, this commentary of the alleged Four Masters is the most interesting and ancient Salernian work which has been{084} preserved, and is well worthy the attention of even modern surgeons.