Metal corrosion will begin if cracks in the protective oxide layer allow oxygen to penetrate. These cracks could be blocked by mineral oil, wax, and lacquer. Treatment of the metal, including silver, copper, bronze, brass, iron, tin, and lead, used in the construction and decoration of instruments is discussed in detail. Both cleaning and protection are considered, with the following recommended for use: Cortec VC1 as a vapor phase inhibitor for silver, Derust for cleaning iron, Incralac for protecting copper, and an alkyl alkoxysiloxane for iron. Names and addresses of suppliers are provided.