O--What is the (R. N., etc.)? Interrogatory. (Ardois and semaphore only.) . . -- -- . . -- What is the (R. N., etc.)? Interrogatory. (All methods but Ardois and semaphore.) P--Affirmative. Yes. PS--Percussion. Shrapnel. QRQ--Send faster. QRS--Send slower. QRT--Cease sending. R--Acknowledgment. Received. RS--Regimental station. RL--Right from the left. RR--Right from the right. RN--Range. RT--Right. S--Subtract. SCL (numerals)--On 2d piece close by (so much). SOP (numerals)--On 2d piece open by (so much). SH--Shell. SI--Site. SSS--Support needed. T--Target. TCL (numericals)--On 3d piece close by (so much). TOP (numerals)--On 3d piece open by (so much). U--Up. Y (letter)--Such battery station. CHAPTER XIII. FIRST-AID RULES. The bandages and dressings contained in the first-aid packet have been so treated as to destroy any germs thereon. Therefore, when dressing a wound, be careful not to touch or handle that part of the dressing which is to be applied to the wound. A sick or injured person should always be made to lie down on his back, if practicable, as this is the most comfortable position, and all muscles may be relaxed. All tight articles of clothing and equipment should be loosened, so as not to interfere with breathing or the circulation of the blood. Belts, collars, and the trousers at the waist should be opened. Don't let mere onlookers crowd about the patient. They prevent him from getting fresh air and also make him nervous and excited. In case of injury the heart action is generally weak from shock, and the body, therefore, grows somewhat cold. So don't remove any more clothing than is necessary to expose the injury. Cut or rip the clothing, but don't pull it. Try to disturb the patient as little as possible. Don't touch a wound with your fingers or a handkerchief, or with anything else but the first-aid dressing. Don't wash the wound with water, as you may infect it. Don't administer stimulants (whisky, brandy, wine, etc.) unless ordered to do so by a doctor. While in a few cases stimulants are of benefit, in a great many cases they do positive harm, especially where there has been any bleeding. The heart may be considered as a pump and the arteries as a rubber hose, which carry the blood from the heart to every part of the body. The veins are the hose which carry the blood back to the heart. Every wound bleeds some, but, unless a large artery or a large vein is cut, the bleeding will stop after a short while if the patient is kept quiet and the first-aid dressing is bound over the wound so as to make pressure on it.