Mercury (Mercurius) is a highly toxic, silvery-white, shiny metal, which is the only metal that remains liquid at normal temperatures. Whether as elemental mercury, mercury vapor, mercury I and II salts or organic mercury compounds, it remains harmful to health in any form. Mercury can be absorbed through inhalation of mercury vapour and atomization of mercury salts. It is absorbed through the skin and mucous membranes. Elemental mercury is the most vaporizable form of the metal. Even at room temperature, compression or slight movement, mercury gives off vapors. Elemental mercury is used in the manufacture of amalgam fillings. The toxic potential of mercury in dentistry is limited to mercury vapor.