[AS. lad.] A well-known metal of a bluish-white color, very heavy, easily melted and cut, and which may be hammered or rolled out into sheets and drawn into wire. It has been used from very early times, and articles made of it by the ancient Romans - such as wrier-pipes, water-tanks, weights, rings, etc. - have been found. Lead is soft, highly malleable, and a poor conductor of heat or electricity. It is largely used for water-pipes and cisterns, and for covering the roofs and gutters of houses. Lead is found in a large number of minerals, though often in very small quantities. Most of the lead now in use is obtained from the ore called galena or sulphide of lead. This ore is found in many parts of the world, but the purest veins are got in Great Britain, Germany, Spain, and the United States. The process of smelting the galena ore to get the pure lead differs from that of smelting iron ore, and is done in an entirely different kind of furnace. Sheet lead is made by rolling slabs of lead between heavy iron rollers until they are thin. Thick sheets are used for lining tanks and water cisterns, and for covering roofs, and thin sheets for wrapping up snuff, lining tea-chests, etc. Lead is used in alloy with other metals - forming, when mixed with arsenic, the alloy from which shot is made ; with tin, pewter and solder ; and with antimony, type-metal. Lead and its compounds are poisonous.