Mercuric amidochloride

It arises from the reaction of mercury(II) chloride and ammonia (Calomel reaction), where the resulting mercuric amidochloride is highly insoluble. It forms white crystals in the shape of small prisms. It has been described as having an earthy, metallic flavor. It is stable in air, but darkens on exposure to light. It does not melt, even at dull red heat, instead subliming and decomposing to gaseous mercury, hydrogen chloride, and nitrogen oxides. Consequently, sealed containers with this chemical may explode when heated. The substance is a lethal poison. ==Uses==

Before the toxicity of mercury was revealed, mercuric amidochloride, then known as ammoniated mercury or white precipitate, was used as a topical skin antiseptic, especially for impetigo, dermatomycosis and other certain dermatoses. It was also used for scaling in psoriasis, to treat pruritus ani, and against pinworm and ringworm infection (especially in dogs), against crab louse infestation, against lesions on the body and near eyes, against bumblefoot infection on poultry, and as a disinfectant. Chronic use of this medication can lead to systemic mercury poisoning. ==See also==