The seeds dried ripe of Delphinium staphisagria.

Characters. - Irregularly triangular or obscurely quadrangular, arched, blackish-brown when fresh, but becoming dull greyish-brown by keeping. Testa wrinkled and deeply pitted; nucleus soft, whitish, oily. No marked odour; taste nauseously bitter and acrid.

Composition. - They contain several alkaloids, the most important being delphinine and staphisagrine.

B.P. Preparation.

Ungruentum Staphisagriae . (Crushed seeds, 1; macerated in benzoated lard, 2, for two hours, and strained.)

Action. - Staphisagrine paralyses the motor nerves in frogs, like curare, and kills mammals without convulsions by paralysing the respiration. Delphinine resembles aconitine in many respects, and like it causes slowness of the pulse and respiration, paralysis of the spinal cord, and death by asphyxia. It stimulates the vagus centre in the medulla, and also the accelerating centre for the heart (p. 318). It slows the respiration, apparently by an action on the slowing fibres of the vagus, for when the vagi are cut, it quickens respiration, probably by stimulating the respiratory centre in the medulla. In advanced stages of poisoning it paralyses the ends of the vagus in the heart and also the cardiac muscle. It removes the still-stand caused by muscarine and digitalin (Boehm). By depressing the action of the spinal cord it arrests the convulsions caused by strychnine.

Uses. - Stavesacre ointment is used to destroy pediculi.