All this may be kept up for several hours. The first sign of recovery is often seen in the slight pinkish tinge of the lips or finger-nails. That the pulse cannot be felt at the wrist is of little value in itself as a sign of death. Life may be present when only the most experienced ear can detect the faintest heart-beat. When a person can breathe, even a little, he can swallow. Hold smelling-salts or hartshorn to the nose. Put one teaspoonful of the aromatic spirits of ammonia, or even of ammonia water, into a half-glass of hot water, and give a few teaspoonfuls of this mixture every few minutes. Meanwhile do not fail to keep up artificial warmth in the most vigorous manner. 379. Methods of Artificial Respiration. There are several well-established methods of artificial respiration. The two known as the Sylvester and the Marshall Hall methods are generally accepted as efficient and practical. Illustration: Fig. 165.—The Sylvester Method. (Second movement—expiration.) 380. The Sylvester Method. The water and mucus are supposed to have been removed from the interior of the body by the means above described (sec. 378). The patient is to be placed on his back, with a roll made of a coat or a shawl under the shoulders; the tongue should then be drawn forward and retained by a handkerchief which is placed across the extended organ and carried under the chin, then crossed and tied at the back of the neck. An elastic band or small rubber tube or a suspender may be used for the same purpose. The attendant should kneel at the head and grasp the elbows of the patient and draw them upward until the hands are carried above the head and kept in this position until one, two, three, can be slowly counted. This movement elevates the ribs, expands the chest, and creates a vacuum in the lungs into which the air rushes, or in other words, the movement produces _inspiration_. The elbows are then slowly carried downward, placed by the side, and pressed inward against the chest, thereby diminishing the size of the latter and producing _expiration_. These movements should be repeated about fifteen times each minute for at least two hours, provided no signs of animation show themselves. 381. The Marshall Hall Method. The patient should be placed face downwards, the head resting on the forearm with a roll or pillow placed under the chest; he should then be turned on his side, an assistant supporting the head and keeping the mouth open; after an interval of two or three seconds, the patient should again be placed face downward and allowed to remain in this position the same length of time. This operation should be repeated fifteen or sixteen times each minute, and continued (unless the patient recovers) for at least two hours. Illustration: Fig. 166.—The Marshall Hall Method. (First position.)