COPPER, n. A metal, of a pale red color, tinged with yellow. Next to gold, silver and platina, it is the most ductile and malleable of the metals, and it is more elastic than any metal, except steel, and the most sonorous of all the metals. It is found native in lamins or fibers, in a gangue almost always quartzous; it is also found crystalized, and in grains or superficial lamins on stones or iron. It is not altered by water, but is tarnished by exposure to the air, and is at last covered with a green carbonated oxyd. Copper in sheets is much used for covering the bottoms of ships, for boilers and other utensils; mixed with tin and zink, it is used in enamel-painting, dyeing, _c. : mixed with tin, it forms bell-metal; with a smaller proportion, bronze; and with zink, it forms brass, pinchbeck, _c. When taken into the body ti operates as a violent emetic, and all its preparations are violent poisons.

, v.t. To cover or sheathe with sheets of copper; as, to copper a ship.