APOCYNUM is the dried root of Apocynum cannabinum, also known as American hemp, Canadian hemp and dogbane. The only official preparation for use as a drug is the fluid extract pre pared from the powdered root. The dose is five minims (0.3cc.) for therapeutic purposes. Its action in this dosage is to stimulate directly the heart muscle and the constricting muscles of the blood-vessels, thus producing a stronger and slower heart beat and a rise in blood pressure. It also increases the output of urine in certain conditions, notably cardiac dropsy. In larger doses it is a powerful gastrointestinal irritant, producing vomiting and purg ing. It closely resembles digitalis in its effect, except that it is not accumulated in the body as is digitalis. Its use is limited to cases of cardiac dropsy where digitalis has failed or has produced undesirable effects.