It is said to have the power of obliterating the trunk of a varicose vein (Bonnet), and also of destroying superficial naevi (Wardrop); but the application is painful, and is apt to leave a very evident cicatrix. Powdered nitrate of potash kept in contact with the naevus, is said to give a better result in slight cases.

In Hospital Gangrene, the part may be first dressed with the solid caustic, and afterward with a lotion containing it in gradually diminishing proportion - 400 cases are said to have been treated successfully by this means (Restelle: British and Foreign Review, October, 1850). Lotions of permanganate and of chlorate are also valuable.