Degeneration and disturbance of the heart muscle and cardiac dilatation are found more and more frequently at an earlier age than such conditions should normally occur. Several factors are at work in causing this condition. In the first place, infants and children are now being saved though they may have inherited, or acquired, a diminished withstanding power against disease and against the strain and vicissitudes of adult life. Other very important factors in causing the varied fortes of cardiac disturbances are the rapidity and strenuousness of a business and social life, and competitive athletics in school and college, to say nothing of the oversmoking and excessive dancing of many. The symptoms of heart strain, if the condition is acute, are those of complete prostration, lowered blood pressure, and a sluggishly, insufficiently acting heart. The heart is found enlarged, the apex beat diffuse and there may be a systolic blow at the mitral or tricuspid valve. Sometimes, although the patient recognizes that he has hurt himself and strained his heart, he is not prostrated, and the full symptoms do not occur for several hours or perhaps several days, although the patient realizes that he is progressively growing weaker and more breathless. The treatment of this acute or gradual dilatation is absolute rest, with small doses of digitalis gradually but slowly increased, and when the proper dosage is decided on, administered at that dosage but once a day. Cardiac stimulants should not be given, except when faintness or syncope has occurred, and if strychnin is used, it should be in small closes. The heart nay completely recover its usual powers, but subsequently it is more readily strained again by any thoughtless laborious effort. The patient must be warned as carefully as though he had a valvular lesion and had recovered from a broken compensation, and his life should be regulated accordingly, at least for some months. If he is young, and the heart completely and absolutely recovers, the force of the circulation may remain as strong as ever. Sometimes the heart strain is not so severe, and after a few hours of rest and quiet the patient regains complete cardiac power and is apparently as well as ever; but for some time subsequently his heart more easily suffers strain. Chronic dilatation of the heart, However, perhaps not sufficient to cause edema, slowly and insidiously develops from persistent strenuosity, or from the insidious irritations caused by absorbed toxins due to intestinal indigestion. A fibrosis of the heart muscle and of the arterioles gradually develops, and the heart muscle sooner or later feels the strain.