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Du Barry, Jeanne Bécu, comtesse

Du Barry, Jeanne Bécu, comtesse, 1743-93, mistress of King Louis XV of France. A courtesan of illegitimate birth, she was the mistress of Jean Du Barry when her beauty attracted (1768) the king's attention. After being nominally married to her lover's brother, Guillaume, comte Du Barry, she was installed at court (1769) and retained her influence until the king's death (1774), but she lacked the ambition of her predecessor, Mme de Pompadour. At the accession of Louis XVI she left the court. She was arrested by the Revolutionary Tribunal on charges of treason (1793) and was guillotined.

See biographies by S. Loomis (1959), A. Stoeckl (1966), and M. Ward (1968).

The Columbia Electronic Encyclopedia Copyright © 2004.
Licensed from Columbia University Press

Cu, symbol for the element copper.

The Columbia Electronic Encyclopedia Copyright © 2004.
Licensed from Columbia University Press

porphyry copper deposit

A large body of igneous rock, having distinct crystals in a relatively fine-grained base, that contains chalcopyrite and other sulfide minerals. These deposits contain vast amounts of ore that averages a fraction of 1percnt copper by weight; although low-grade, the deposits are important because they can be worked on a large scale at low cost. Large porphyry copper deposits are worked in the southwestern U.S. (where molybdenum may be produced as a by-product), the Solomon Islands, Canada, Peru, Chile, Mexico, and elsewhere.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.

copper (butterfly)

Any member of the butterfly subfamily Lycaeninae (family Lycaenidae). Coppers are common and widely distributed. Adults, sometimes known as gossamer-winged butterflies, are delicate, with a wingspan of 0.75–1.5 in. (18–38 mm). They are rapid fliers, usually with iridescent wings. Coppers typically range from orange-red to brown, usually with a copper tinge and dark markings. Copper larvae feed on clover, dock, or sorrel.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.

copper

Crystalline copper from Michigan

Metallic chemical element, one of the transition elements, chemical symbol Cu, atomic number 29. Sometimes found in the free state in nature, it is a reddish metal, very ductile and an unusually good conductor of electricity and heat. Most of the world's copper production is used by the electrical industries; the remainder is combined with other metals (e.g., zinc, tin, nickel) to form alloys such as brass, bronze, nickel silver, and Monel. Copper is part of nearly all coinage metals. In compounds copper usually has valence 1 (cuprous) or 2 (cupric). Cuprous compounds include cuprous oxide, a red pigment and a fungicide; cuprous chloride, a catalyst for certain organic reactions; and cuprous sulfide, with a variety of uses. Cupric compounds include cupric oxide, a pigment, decolorizing agent, and catalyst; cupric chloride, a catalyst, wood preservative, mordant, disinfectant, feed additive, and pigment; and cupric sulfate, a pesticide, germicide, feed additive, and soil additive. Copper is a necessary trace element in the human diet and essential to plant growth; in blue-blooded mollusks and crustaceans it plays the same role in hemocyanin as iron does in hemoglobin.

Learn more about copper with a free trial on Britannica.com.

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.