babies, treatment directed against rickets is usually desirable; the child must remain outdoors as much as possible; the diet should be improved; one-half to one teaspoonful of an "emulsion of cod-liver oil with hypophosphites" may be given three times daily, and pure cod-liver oil rubbed all over the body once daily after the bath. If the soles of the shoes are made thicker along the outer borders it will favor correction of bowlegs, when the child begins to walk. In older children, when bowlegs are very pronounced, and the deformity is of long standing, correction can only be secured through the application of apparatus by the surgeon, or through operation, such as cutting loose part of the bones of the thighs and setting them in proper position.

KNOCK-KNEES.-This is a deformity acquired in infancy, owing to rickets-with malformation of the bones of the legs—but may develop in later life, owing to weakness of the ligaments on the inner side of the knee joint. In knock-knee, the knees are in close contact, and the feet held apart. A slight degree of this condition is seen naturally in women. Knock-knee is not recognized by parents so readily as bowlegs. After the child has begun to walk, it may show the trouble by an awkward, waddling gait, and by frequently stumbling and falling, and the deformity may be seen when the child is standing erect or lying with the legs stretched at full length. The deformity does not tend to correct itself, as in the case with bowlegs. The treatment with cod-liver oil and outdoor life, advised

for bowlegs, is appropriate for knock-knee in infancy. Also the legs should be well rubbed and kneaded, and straightened by pressing upon the inside of the knee joints with the palm of one hand, while the ankle is grasped with the other. Such treatment should be employed for ten minutes at a time twice each day. If such measures do not correct the deformity, it will be necessary for a physician to apply braces, which will usually cure the condition in children under six. After this age an operation to break or cut the bones above the knee is often required to secure a good result.

Part VII

CIRCULATION AND DIGESTION

BY

KENELM WINSLOW

AND

ALBERT WARREN FERRIS

CHAPTER I

The Heart

Valvular Affections-Causes of Heart Disease-Careful Exami nations Necessary-Treatment of Palpitation-Blood Analysis -Anemia.

HEART DISEASE. The heart is a hollow muscle which withdraws blood from one set of blood vessels (the veins) and pumps it into another set (the arteries) and thus keeps the blood moving about the body. Within the heart are chambers and valves to prevent the blood from flowing back from the arteries into the heart and from the heart into the veins, as the valves in a pump prevent the water from flowing back into the well when the piston is lowered. In heart disease the muscle is either altered in structure through the influence of poisons-most of which are produced by the germs causing the acute diseases or the valves of the heart become defective; that is, the valves do not close properly and are leaky, or else they become obstructed. Such defects constitute what is called valvular disease, which is the most common form of chronic disease of the heart. The effect of such a condition is that the heart does not pump sufficient blood into the arteries, because it leaks back into the [Text continued on page 441.]