=Treatment.=--The best treatment consists in rest in bed on a hard mattress; the patient lying flat on the back with a small pillow between the shoulders and the forearm of the injured side across the chest. This is a wearisome process, as it takes from two to three weeks to secure repair of the break. On the other hand, if the forearm is carried in a sling, so as to raise and support the shoulder, while the patient walks about, a serviceable result is usually obtained; the only drawback being that an unsightly swelling remains at the seat of the break. To make a sling, a piece of strong cotton cloth a yard square should be cut diagonally from corner to corner, making two right-angled triangles. Each of these will make a properly shaped piece for a sling. (See Figs. 10 and 11.) Fracture of the collar bone happens very often in little children, and is commonly only a partial break or splitting of the bone, not extending wholly through the shaft so as to divide it into two fragments, but causing little more than bending of the bone (the "green-stick fracture"). [Illustration: FIG. 10. HOW TO MAKE A SLING (SCUDDER). In Fig. 10 note three-cornered bandage; No. 2 end is carried over right shoulder, No. 1 over left, then both fastened behind neck; No. 3 brought over and pinned.] [Illustration: FIG. 11. HOW TO MAKE A SLING (SCUDDER). The above illustration shows sling in position. It is made of cotton cloth a yard square cut diagonally from corner to corner.] A fall from a chair or bed is sufficient to cause the accident. A child generally cries out on movement of the arm of the injured side, or on being lifted by placing the hands under the armpits of the patient. A tender swelling is seen at the point of the injury of the collar bone. A broad cotton band, with straps over the shoulders to keep it up, should encircle the body and upper arm of the injured side, and the hand of the same side should be supported by a narrow sling fastened above behind the neck. =LOWER-JAW FRACTURE.= _First Aid Rule.--Put fragments into place with your fingers, securing good line of his teeth. Support lower jaw by firmly bandaging it against upper jaw, mouth shut, using four-tailed bandage. (Fig. 12.)_ Fracture of the lower jaw is caused by a direct blow. It involves the part of the jaw occupied by the lower teeth, and is more apt to occur in the middle line in front, or a short distance to one side of this point. The force causing the break usually not only breaks the bone, but also tears the gum through into the mouth, making a compound fracture. There is immediate swelling of the gum at the point of injury, and bleeding. The mouth can be opened with difficulty.