Strophanthus extract and Strophanthin are substances of great pharmacological activity, as, by subcutaneous administration, Strophanthin produces death in average-sized frogs with a dose of . of a grain, and in rabbits weighing about 3 lbs. with a dose of of a grain. The kind of action is the same with both substances, and therefore Strophanthin may properly be regarded as the active principle of Strophanthus hispidus.