Formulas or Etching Steel.-Any one of the following formulas is useful for etching steel:

Etching Reagents for Nonferrous Metals.-To etch nickel and monel metal use concentrated hydrochloric acid, or a mixture of nitric and acetic acids; for copper, brass, and bronze use 1 volume of hydrogen peroxide and 10 volumes of ammonium hydroxide; for brass high in zinc use concentrated ammonium chloride; for aluminum bronze use the same as for nickel.

The typical reagents for etching nonferrous metals are ammonium hydroxide, dilute sulphuric acid, and ammonium chloride. A stream of oxygen directed against the surface to be etched will greatly aid the action of the solutions.

FIRST AID TO THE INJURED

PREPARATION

In every place where a large number of persons are employed and where accidents are liable to occur, a supply of articles needed to render first aid should be available. These should include one or more stretchers, bandages, absorbent cotton, carron-oil (equal parts of raw linseed-oil and lime-water), splints, soap, towels, blankets, aromatic spirits of ammonia, etc. The necessary quantity of any of these or other articles depends on the nature and size of the works.

Sterilizing. Many disease germs may be killed by heat; others by chemicals called disinfectants, such as bichloride of mercury, carbolic acid, etc. The solutions used in washing wounds should be made up of about the following strengths: Bichloride of mercury, 15 gr. to 1 qt. of water; or, liquid carbolic acid, 2 teaspoonfuls to 1 qt. of water. The substances should be thoroughly dissolved before the solution is used.

ACCIDENTS AND INJURIES

FAINTING

Fainting, or swooning, with loss of sensation, motion, and consciousness, may result from a severe blow or wound, from loss of blood, from great emotion (extreme fear or joy), from electric shock, etc. The patient becomes pale, inanimate, and is in a condition of apparent death; if not soon relieved, death may result.

The patient should be laid with the head lower than the feet, and ligatures or bands of some sort should be tied around the arms and legs close to the body, so as to confine the circulation to the trunk and head. The tongue should be kept out of the throat, in order to allow free access of air, and the respiration may be helped by pressing in and down on the ribs and chest and allowing the chest to expand by its own elasticity.

Artificial Respiration.-The process just described is one form of artificial respiration, and may in some cases be effective. If the desired results are not soon obtained, place the patient on his back with a pad (a roll of clothing will do) under the back just below the shoulders, so

as to raise the pit of the stomach. The patient's tongue should be drawn out and held by an assistant, or, it should be fastened against the lower teeth by a rubber band passing under the chin or clasped between the patient's teeth, the lower jaw being held up by a bandage tied over the head. Grasp the forearms half way between the elbows and wrists, and draw the arms back rather quickly but steadily in vertical planes until they meet above the patient's head, as in Fig. 1, and hold them thus for 2 sec. This motion draws the ribs up, expands the chest, and air enters. Now bring the arms back to the sides of the body, and press firmly on the sides and front of the chest over the lower ribs, as in Fig. 2; the object of this movement is to

contract the chest and force the air out of the lungs. If enough assistants are present, one can stand astride the patient and press firmly against the sides and top of the chest while the arms are held down along the sides. This series of movements, constituting one inspiration and one expiration, should be repeated about once every 4 sec., or fifteen times per min., for 1 or 2 hr. if necessary, unless in the meantime a physician pronounces life extinct. While working over the patient prevent unnecessary crowding of persons, avoid rough usage, and do not allow the patient

Under

to remain on his back unless his tongue is secured. no circumstances should the patient be held up by his feet, nor should he be placed in a warm bath unless under medical direction.

TRAUMATIC SHOCK

Severe injuries may sometimes result in traumatic shock (trauma meaning a wound), in which the victim appears confused and listless and perhaps stupefied, but not unconscious. The pulses and respiration are perceptible, though feeble and irregular. Sometimes the bowels move involuntarily. Intelligence is not usually wholly lost, and the patient can be made to respond to questions if repeatedly urged. This condition may last a few moments or several hours, and may terminate in death.

Place the patient in a horizontal position with head lowered, and warm him by rubbing and by using warm linen or blankets. Let him inhale the odor from dilute ammonia water. If he can swallow, give a little hot brandy and water with a few drops of ammonia water added; 1 teaspoonful of aromatic spirits of ammonia in a wineglassful of water is also good. From 2 to 4 teaspoonfuls of turpentine in a quart of water, as hot as may be used without discomfort, may be injected into the bowels, often with good results.

Wounds consisting of severe bruises are sometimes characterized by numbness, coldness, and absence of bleeding until reaction begins. In such cases, use stimulants and antiseptics and keep the injured part as quiet as possible and protected by warm dressing.

HEMORRHAGE, OR BLEEDING

Hemorrhage, or bleeding, may come from the arteries, the veins, or the capillaries. The arteries are the channels through which blood flows from the heart to the various parts of the body, and the veins are the channels through which the blood returns to the heart. The capillaries form the network of very minute tubes through which the blood passes from the arteries to the veins and by which all the tissues of the body are nourished.

Arterial hemorrhage is usually distinguished by the bright red color of the blood and the regular pulsations with which it issues from the blood vessels; venous hemorrhage can be known by the dark-blue tint of the blood and the steadiness of its flow; in capillary hemorrhage, the blood has a reddish tint and exudes from the tissues or wells up from the surface of the wound. Internal hemorrhage may exist without any external flow of blood.

After excessive loss of blood, the patient's face and lips turn pale; he experiences chills, cold sweats, nausea, frequent vomiting, irregular respiration, feeble pulse, dizziness, buzzing in the ears, and finally unconsciousness, terminating either in death or in the cessation of the bleeding. In the latter case, consciousness may soon return, but very often the tendency to fainting fits persists for a time.