seconds. Then immediately swing backward so as to remove the pressure, returning to the position shown in figure 7. Repeat regularly 12 to 15 times per minute the swinging forward and backward, completing a respiration in four or five seconds.

FIGURE 7.-Schaefer method of artificial respiration. Inspiration.

As soon as this artificial respiration has been started and while it is being conducted an assistant should loosen any tight clothing about the subject's neck, chest, or waist. Continue the artificial respiration without interruption until natural breathing is restored (if necessary two hours or longer) or until a physician arrives. If natural breathing stops after having been restored, use artificial respiration again.

FIGURE 8.-Schaefer method of artificial respiration. Expiration.

Do not put any liquid in the patient's mouth until he is fully conscious.

Give the patient fresh air, but keep him warm.

Send for the nearest doctor as soon as the accident is discovered.

SILVESTER METHOD OF ARTIFICIAL RESPIRATION.

Place the patient on his back, fold a blanket or coat, and put it under his shoulders so as to throw the chest forward.

Press open his mouth, grasp his tongue, draw it forward, and let an assistant hold it or tie it out with a gauze bandage or a shoestring, or tear a handkerchief into strips and tie them together, thus making a string. Place the bandage or string over the tongue, draw the ends down, one on either side of the jaw, crossing them underneath the chin, and bring back one end to each side of the head. Tie the ends on top of the head. This action holds the tongue forward. In an emergency, the tongue can be held forward with a safety pin.

The Bureau of Mines relief kit contains an oral screw with which to force open the jaws, a pair of tongue forceps for grasping the tongue and drawing it forward, a glass tube in which there is a curved needle, and a sterile catgut thread. In case of emergency, the firstaid man can run the needle and thread through the tongue and thus hold it out. Every first-aid miner is required to carry one of these cases at all times.

After getting the tongue out, kneel by the patient's head, grasp both arms just below the elbows, and draw them upward and backward toward you as far as they will go (fig. 9). This action allows air to enter the lungs, producing inspiration. Then raise the arms and bring them inward and downward to the chest, applying pressure sufficient to expel the air, thus producing expiration (fig. 10). These movements should be performed at the rate of 16 to 18 times per minute. As soon as signs of life appear the lower limbs should be elevated and rubbed vigorously toward the heart. Hot applications should be used over the heart if practicable. If there is no sign of life, keep up the artificial respiration for at least two hours, as the patient may be breathing, although not appearing to be doing so. Some patients have been revived after several hours of hard work. If the patient regains consciousness and is able to swallow, give hot coffee or half-teaspoonful doses of aromatic spirits of ammonia and treat as in shock. (See "Shock.")

USE OF RESUSCITATION DEVICES.

In all cases of insufficient respiration-that is, when the patient breathes regularly but very slowly-artificial respiration should not be given, either by the Schaefer or the Silvester method, but, if possible, nature should be allowed to restore the natural rate of breathing unaided.

The patient may with advantage be allowed to breathe pure oxygen, which may be supplied from a cylinder containing the gas under pressure; a reducing valve to lower the pressure, and a breathing bag with connecting tubes, face mask, and inspiratory and

FIGURE 9.-Sylvester method of artificial respiration. Extending the arms.

expiratory valves being used. The oxygen may be supplied by an oxygen generator; if this be done, no reducing valve will be necessary. Various types of mechanical devices for reviving asphyxiated persons have been devised and one or two have been widely used. Since the first edition of this circular was printed a committee on resuscitation from mine gases, appointed at the recommendation of the American Medical Association to advise the Bureau of Mines, has made a report on the use of such devices.

This committee has declined to recommend any of the mechanical resuscitation devices that it examined, giving the following reasons:

1. Artificial respiration by mechanical devices is seldom practicable in mines because these devices are heavy and are rarely available in time to make their use effective. If a man's breathing has stopped, a delay of one or two minutes in administering artificial respiration is liable to be fatal. For this reason manual methods, such as the Schaefer, which can be applied immediately, are preferable to any mechanical device.

2. The lungs of the patient are liable to be injured by the repeated suction of air by some types of resuscitation apparatus.

3. In cases of poisoning by carbon monoxide, a high percentage of oxygen in the air inhaled by the victim is more important than the extent to which the lungs are filled or emptied by mechanical means. Carbon monoxide poisons a man by combining with the red coloring matter of his blood and thus preventing the blood from carrying the necessary amount of life-giving oxygen to the tissues of his body. A victim of carbon-monoxide poisoning can be revived if the carbon monoxide that his blood has absorbed can be replaced by oxygen. The blood of a living man is never completely saturated with carbon monoxide, and a man who has been overcome by breathing carbon monoxide can be revived, if he is not too far gone, by causing him to breathe pure oxygen. As ordinary air is only about one-fifth oxygen, the blood can absorb five times as much oxygen when a man breathes pure oxygen as when he breathes ordinary air. For this reason oxygen, if obtainable, should be given to men overcome by white damp or afterdamp. The oxygen should be given in the manner already stated; that is, by a breathing bag properly connected to a source of supply and a face mask having suitable valves. In case a man can not breathe, the Schaefer or Silvester method of artificial respiration should be used to cause the oxygen to enter the lungs.

BANDAGES.

Bandages are used to keep dressings in place, to retain splints on broken limbs, to stop bleeding by pressure, and as slings. The kinds of bandages in use are the triangular bandage, the roller bandage, and the special bandage of the United States Army.