It is open to doubt whether ligature of the carotid arteries is ever necessary, though several cases have been recorded in which such a procedure was carried out. The external carotid should be tied in preference to the common vessel, further interference with the blood-supply of the brain increasing necessarily the risk of cerebral œdema, &c. The hæmorrhage having been arrested by one or other of these methods, the cavity is thoroughly washed out with hot saline solution and drained, a small rubber drainage-tube being brought out through the scalp-flap. The tube should be removed after twenty-four to thirty-six hours, according to the circumstances of the case. _For hæmorrhage from the posterior branch._ The ‘site of election’ for exposure of the posterior branch lies at the intersection of the two following lines:-- A line drawn backwards from the upper border of the orbit parallel to Reid’s base-line. A line drawn vertically upwards from the posterior border of the mastoid process. The trephine is applied, the disk removed, and the gap enlarged with the craniectomy forceps in the forward and backward directions. The hæmatoma is evacuated and the bleeding arrested after the methods enumerated above. =Results.= The ultimate result of operation for middle meningeal hæmorrhage depends on two factors--the time at which operation is carried out, and the question of brain lesion. There is every reason to believe that, when treated early and when uncomplicated by brain injury, the prognosis, both immediate and remote, is wholly satisfactory. Wiesman[29] collected 257 cases, of which 110 were submitted to operation, with a mortality of 27 per cent. Of the cases in which no operation was performed 88 per cent. died. Duchaine[30] reports 27 cases in which operation was carried out, with death in 6 cases only, a mortality of 22 per cent. Von Bergmann collected 110 cases treated by operation, with 74 recoveries and 36 deaths, a mortality of 32·27 per cent. Blake only lost 3 cases out of a total of 42 submitted to operation. Even when every allowance is made for the fact that operative measures were adopted in the more hopeful cases, the above statistics show conclusively that early operation affords great hope of cure. [Illustration: FIG. 53. A BASIC FRACTURE WITH LACERATION OF BOTH CAROTID ARTERIES.] Before passing on to =subdural hæmorrhage=, it will be convenient to discuss briefly the question of injury to the =internal carotid artery=.