Besides the instruments of precision referred to above, more careful percussion, more careful auscultation, more careful measurements, roentgenoscopy and fluoroscopic examination of the heart, and a study of the circulation with the patient standing, sitting, lying and after exercise make the determination of circulatory ability a specialty, and the physician who becomes an expert a specialist. It is a specialization needed today almost more than in any other line of medical science. So frequently is the cause of these pains, disturbances and weakness overlooked and the stomach or the intestines treated, or treatment aimed at neuralgias, rheumatisms or rheumatic conditions, that a careful examination of the patient, and a consideration of the part the heart is playing in the causation of these symptoms are always necessary. The treatment required for such a heart, unless there is some complication, as a kidney complication or a too high blood pressure, or arteriosclerosis (and none of these causes necessarily prohibits energetic cardiac treatment), is digitalis. If there is doubt as to the condition of the cardiac arteries, digitalis should be given in small doses. If it causes distinct cardiac pain, it is not indicated and should be stopped. If, on the other hand, improvement occurs, as it generally does, the dose can be regulated by the results. The minimum dose which improves the condition is the proper one. Enough should be given; too much should not be given. Before deciding that digitalis does not improve the condition (provided it does not cause cardiac pain) the physician should know that a good and efficient preparation of digitalis is being taken. Strychnin will sometimes whip up a tired heart and tide it over periods of depression, but it is a whip and not a cardiac tonic. While overeating, all overexertion, and alcohol should be stopped, and the amount of tobacco should be modified, there is no treatment so successful as mental and physical rest and a change of climate and scene, with good clean air. Many persons with these symptoms of cardiac tire think that they are house-tired, shop-tired, or office-tired, and take on a physical exercise, such as walking, climbing, tennis playing or golf playing, to their injury. Such tired hearts are not ready yet for added physical exercise; they should be rested first. The treatment of this cardiac tire is not complete until the tonsils, gums, teeth and the nose and its accessory sinuses are in good condition. Various other sources of chronic poisoning from chronic infection should of course be eliminated, whether an uncured gonorrhea, prostatitis, some chronic inflammation of the female pelvic organs, or a chronic appendicitis.