Pasteurized solutions have the advantage of being sterile and do not decompose as the boiled solutions would. The pasteurization is accomplished as follows: The necessary amount of cocain is dissolved in sterilized water. The solution is put into a sterilized glass bulb, which is sealed hermetically and subjected to a temperature of 60° C. for three hours. Since cocain is a nerve poison, its systemic absorption must be avoided. The constitutional effects of a given amount injected about the head, face, and neck are more marked than when injected in other parts of the body or extremities. This is due to two causes: a more rapid absorption and the proximity to the brain (Ricketts). For this reason less cocain should be used and the blood vessels be avoided. Idiosyncrasy influences greatly these toxic effects. In neurotic patients of irritable and impressionable type the hypodermic use of this agent has especially induced serious syncope. Very serious symptoms and even death have been caused by its local use (⅛ grain hypodermically). Untoward effects are manifested by nausea, vertigo, emesis, syncope, followed by clonic convulsions, delirium, and death. Cocain first stimulates, then paralyzes, the pneumogastric nerve; the respiration is first accelerated, and then paralyzed, death being due to failure of respiration. Should these symptoms occur, the patient should be placed on his back with the head low. Amyl nitrate inhalations act as the antidote and reduce the cerebral anemia (Feinberg). Morphin or caffein is to be given hypodermically, or the former is associated with potassium bromid internally. To overcome the toxic qualities of the anesthetic it may be combined with morphin in solution, Schleich’s solution being well known. It is composed as follows: Cocain murias 0.1 Morph. sulph. 0.025 Sodium chlor. 0.2 Aquæ sterilis. 100.0 Gauthier suggests the addition of one drop of a one-per-cent solution of nitroglycerin to the quantity injected and repeated to prevent the unfavorable after effects. Solutions of cocain are to be made up fresh each day, as they become moldy on standing. They cannot be sterilized, for the reason that a temperature of 213° F. renders them useless. The solution is most active at 50° F. (Costa). For hypodermic purposes two- to ten-per-cent solutions are employed, the four per cent being more generally used, not more than 0.1 gram of the agent being introduced (Hänel, ano). [Illustration: FIG. 34.—SIMPLEX SYRINGE.] [Illustration: FIG. 35.—KOLLE IMPROVED PRAVAZ SYRINGE.] [Illustration: FIG. 36.—“SUB-Q” SYRINGE.]