Since Withering1 established the empirical fact that the powdered leaves of foxglove were a valuable remedy for the dropsy, many of the pharmacological actions of digitalis have been elucidated. Those that have gained general acceptance are well summarized by Willius2 in three main compartments:
(a) digitalis depresses the function of the sino-auricular and the auriculo-ventricular nodes, and a tendency to slowing of the cardiac rate results;
(b) it depresses conduction throughout the cardiac muscle, particularly through the auriculo-ventricular bundle, and increases the refractory period in both the auricles and ventricles;
(c) it increases the amplitude of cardiac contraction and tends