The administration of calcium with digitalis was considered a safe combination to enhance diuresis and to increase the effects of digitalis by Berliner,1 Billigheimer2 and Singer.15 Recently, however, Bowers and Mengle4 reported sudden death in two patients who received calcium intravenously after previous administration of digitalis, and similar results were noted in animals that received a similar combination. Available experimental evidence points to either a synergistic effect or an additive phenomenon as the underlying factor for such untoward results. Lloyd1 reported the electrocardiographic changes observed on himself during intravenous administration of calcium chloride, using first 50 c.c. of a 1