Except in very severe cases, shock tends towards recovery within a few hours, the _reaction_, as it is called, being often ushered in by vomiting. The colour improves; the pulse becomes full and bounding; the respiration deeper and more regular; the temperature rises to 100° F. or higher; and the patient begins to take notice of his surroundings. The condition of neurasthenia which sometimes follows an operation may be associated with the degenerative changes in nerve cells described by Crile. In certain cases the symptoms of traumatic shock blend with those resulting from toxin absorption, and it is difficult to estimate the relative importance of the two factors in the causation of the condition. The conditions formerly known as "delayed shock" and "prostration with excitement" are now generally recognised to be due to toxæmia. _Question of Operating during Shock._--Most authorities agree that operations should only be undertaken during profound shock when they are imperatively demanded for the arrest of hæmorrhage, the prevention of infection of serous cavities, or for the relief of pain which is producing or intensifying the condition. _Prevention of Operation Shock._--In the preparation of a patient for operation, drastic purgation and prolonged fasting must be avoided, and about half an hour before a severe operation a pint of saline solution should be slowly introduced into the rectum; this is repeated, if necessary, during the operation, and at its conclusion. The operating-room must be warm--not less than 70° F.--and the patient should be wrapped in cotton wool and blankets, and surrounded by hot-bottles. All lotions used must be warm (100° F.); and the operation should be completed as speedily and as bloodlessly as possible. The element of fear may to some extent be eliminated by the preliminary administration of such drugs as scopolamin or morphin, and with a view to preventing the passage of exciting afferent impulses, Crile advocates "blocking" of the nerves by the injection of a 1 per cent. solution of novocaine into their substance on the proximal side of the field of operation. To prevent after-pain in abdominal wounds he recommends injecting the edges with quinine and urea hydrochlorate before suturing, the resulting anæsthesia lasting for twenty-four to forty-eight hours. To these preventive measures the term _anoci-association_ has been applied. In selecting an anæsthetic, it may be borne in mind that chloroform lowers the blood pressure more than ether does, and that with spinal anæsthesia there is no lowering of the blood pressure.