Leadwort. Hab. Southern Europe. Plumbago Rosea. Hab. the East Indies.

Plumbago Zeylandica. Hab. the East Indies.

These three plants (Nat. Ord. Plumbagineae) are powerful irritants when applied externally. Their activity depends upon a crystalline principle, Plumbagin.

Med. Uses. As a vesicant or blister, these plants, but particularly P. Rosea, have been tested in above 300 cases by O'shaughnessy, who regards them as an effectual and cheap substitute for Cantharides. over which they possess the advantage of never producing strangury, nor any other form of irritation of the urinary organs. The bark should be rubbed into a paste with water and a little flour or congee; it occasions pain in about five minutes, which increases in severity till, in a quarter of an hour, it is equal to that of Cantharides. If the paste be removed in half an hour, the pain is soon allayed; and in a period of twelve or eighteen hours a large uniform blister, full of serum, is occasioned. The blistered surfaces heal readily, without unpleasant ulceration. (O'shaughnessy.*)