With respect to =compound= fractures, it is necessary that the bone lesion should be fully exposed, all pockets of scalp-tissue being slit up to their termination. Previous to any attempt at examination of the injured bone, further precautions must be taken to avoid subsequent infection, by reason of the bruised and soiled scalp. Such tags of scalp-tissue as appear injured beyond repair should be cut away with the scissors, and in order to avoid or diminish subsequent wound infection, I have been accustomed to swab over the most suspicious parts with pure carbolic acid, washing away the same with saline solution. Since the advent of iodine sterilization, I have often utilized that solution in preference to the carbolic, swabbing the whole surface exposed. I think a combination of the two methods is advisable in more serious cases, utilizing the carbolic for the margins of the wound and iodine for the general surface. By means of this method the risk of meningeal infection and scalp suppuration is greatly reduced. To aid in the prophylaxis, the patient should again be placed under a course of treatment by urotropin (see p. 116). With regard to the bone, all loose fragments should be removed, only those being preserved which retain their pericranial connexions. Even these are thrown back so as to permit of the maximum inspection of the dura mater. This membrane, if torn, is either sewn up at once or opened up more freely in the investigation and removal of underlying blood-clot or bone-débris. After removing such troubles the membrane is accurately sutured. The bone-flaps are now replaced in position. Some surgeons advocate the replacement of the smaller fragments of bone which have previously been removed. These fragments may be sterilized by boiling, but such a process destroys the bone-cells and, in consequence, they become absorbed, merely acting as scaffolding media for the formation of fibrous tissue. Added to that, in the event of suppuration, the presence of such fragments not only leads to the persistence of a purulent discharge, till the fragments are entirely removed, but also increases considerably the risk of meningeal infection. As a summary, therefore, it may be laid down that it is necessary to remove all loose fragments of bone, the deficiency in the vault being rectified, if necessary, at a later date by one of the methods enumerated in Chapter VI. The scalp-flap is accurately sewn up with interrupted salmon-gut sutures, a gauze or cigarette drain being inserted at the most convenient and dependent point, to be removed at the end of forty-eight hours or more according to the progress of the case.