Calamine the zinc-impregnated gauze wrap used to treat ulcers of the leg in Unna boots. In a 1992 press release, the U.S. Food and Drug Administration announced that no proof had been submitted showing calamine to be safe for use or effective in treating bug bites, stings, and rashes from poison ivy, poison oak, and poison sumac. In a September 2, 2008 document, the U.S. Food and Drug Administration recommended applying topical over-the-counter skin protectants, such as calamine, to relieve the itch caused by poisonous plants such as poison ivy, poison oak, and poison sumac. Calamine Calamine, also known as calamine
Period 6 element in 1839 as an impurity in cerium nitrate – hence the name "lanthanum", from the Ancient Greek "λανθάνειν" ("lanthanein"), meaning "to lie hidden". Although it is classified as a rare earth element, lanthanum is the 28th most abundant element in the Earth's crust, almost three times as abundant as lead. In minerals such as monazite and bastnäsite, lanthanum composes about a quarter of the lanthanide content. It is extracted from those minerals by a process of such complexity that pure lanthanum metal was not isolated until 1923. Lanthanum compounds have numerous applications as catalysts, additives in glass, carbon arc lamps