Considerable attention has been paid to the electrocardiographic changes, particularly of the T wave, following the administration of digitalis. Experiments performed on human beings and on animals have not given the same results in the hands of different observers. Pardee,1 using normal persons and patients with heart disease, found that the T wave began to decrease in amplitude as early as from two to four hours after the administration of tincture of digitalis in doses of 1 minim (0.06 cc.) per pound of body weight. The maximum effect was seen in from six to seven hours, and the change lasted for about twenty-four hours. The same author stated later that similar effects were noted with much smaller doses; in fact, with from one sixth to one eighth of the dose previously mentioned. Pardee2 considered a change in the T wave as a reliable sign not only of the beginning action