“Repeat these movements deliberately and perseveringly, fifteen times only in a minute. (When the patient lies on the thorax, this cavity is compressed by the weight of the body, and expiration takes place. When he is turned on the side, this pressure is removed, and inspiration occurs.) “When the prone position is resumed, make a uniform and efficient pressure along the spine, removing the pressure immediately, before rotation on the side. (The pressure augments the expiration; the rotation commences inspiration.) Continue these measures. “Rub the limbs upward, with firm pressure and with energy. (The object being the return of venous blood to the heart.) “Substitute for the patient's wet clothing, if possible, such other clothing as can be instantly procured, each by-stander supplying a coat or cloak, etc. Meantime, and from time to time, to excite inspiration, let the surface of the body be slapped briskly with the hand. “Rub the body briskly till it is dry and warm, then dash cold water upon it, and repeat the rubbing. “Avoid the immediate removal of the patient, as it involves a dangerous loss of time; also, the use of bellows, or any forcing instrument; also, the warm bath and all rough treatment.” * * * * * Describe the first step recommended by Marshall Hall in the case of asphyxia from drowning, chloroform, coal-gas, etc. How would you clear the throat? How is respiration or breathing excited? What should be done to the face? If not successful in reviving the patient, what should be done to excite respiration? How often should this movement be repeated? Explain how respiration is produced by this proceeding. What is the next step? Explain its meaning. What should be done with the limbs? What is the object? What of the patient's wet clothing? What should be done from time to time? What else is recommended to be done? What should be avoided? Now, give every step to be taken in resuscitating persons by Hall's method. CHAPTER XI. THE MUSCLES. You are provided by nature with about four hundred muscles. Every one has its special use. They are fastened to the bones, which can only be moved by them. The principal muscles are shown in the figure on page 45. The muscles are generally found in pairs, so that when motion is produced in one direction, another muscle or group of muscles causes motion in the opposite direction. VOLUNTARY AND INVOLUNTARY MUSCLES. A voluntary muscle is one which you can control; an involuntary muscle is not subject to your will. Thus, when you move your hand or foot, it is done by a voluntary muscle. Your heart beats without any will of your own, and is therefore, controlled by involuntary muscles. STRENGTH OF MUSCLES.