3. After doses of Urotropin, within therapeutic limits, a sufficient amount of the drug appears in the cerebro-spinal fluid to exercise a decided inhibitory effect on the growth of organisms inoculated into this fluid after its removal from the body. 4. Following a subdural inoculation of dogs and rabbits with streptococcus, 60-80 grains of Urotropin a day, given under conditions which insure absorption, will markedly defer, and in some cases prevent, the onset of a fatal meningitis. 5. In view of these observations, the prompt administration of Urotropin is advised in all clinical cases in which meningitis is a possible or threatened complication, or even when meningeal infection has actually occurred. [Illustration: FIG. 44. A TEMPERATURE CHART ILLUSTRATING THE CHANGES IN TEMPERATURE OBSERVED IN HEAD-INJURIES. (For description, see text.)] Acting on these suggestions, I am accustomed to treat all head cases with this drug, 10-20 grains three times a day by mouth. It may be given per rectum, though probably with less satisfactory results. Traumatic cases are treated as soon as possible, other cases receive their dose for two or three days previous to the operation, the drug being continued till all fear of possible meningeal infection has vanished. In discussing the general treatment of basic fractures, it must be accepted that the basic fracture in itself requires no treatment. Danger or death is dependent on intracranial complications, and an uncomplicated basic fracture demands no active surgical treatment. The special treatment applicable to cases complicated by hæmorrhages, both external to and beneath the dura mater, is discussed in the next chapter. It is therefore only necessary to enter into those cases of fractured base which are associated with concussion, irritation, and compression of the brain--in other words, the _average_ case of fracture of the base of the skull. The surgeon must always be guided by the general condition of the patient--the blood-pressure, character of pulse, state of respiration, depth of unconsciousness, &c.--but, in my opinion, the temperature chart affords perhaps the most valuable basis on which rules can be formulated guiding the surgeon in his general line of treatment.