Caracas \ka-'ra-kas, ko-Ta-kosV City (pop. 2001: 1,836,000), capital of Venezuela. Its Caribbean Sea port is La Guaira. Lying at an elevation of about 3,000 ft (900 m), Caracas is one of the most developed cities in Latin America. It was founded in 1567 by Diego de Losada. It is the birthplace of Simon Bolivar (1783), under whose leadership it became the first colony to revolt against Spain (c. 1810). Caracas has become the country’s primary centre of industry, commerce, education, and culture.
Caramanlis, Constantine See Konstantinos Karamanlis
Caravaggio \,kar-3-'va-jo\ orig. Michelangelo Merisi (b. 1571?, Milan?—d. July 18, 1610, Port’Ercole, Tuscany) Italian painter. He was orphaned at 11. After an apprenticeship in Milan, he went to Rome in 1590, where he won the patronage of a cardinal. A series of large paint¬ ings (1599-1603) on the life of St. Matthew established him as the most renowned and controversial painter in Rome of his era. Breaking with conventional formulas used in depicting saints, he used ordinary people as models and painted them with unforgiving realism; his inclination against tradition gave new meaning to the interpretation of traditional themes in religious painting. His use of tenebrism—dramatic, selective illumination of form out of deep shadow to heighten the emotional ten¬ sion, focus the details, and isolate the figures—became the most outstand¬ ing feature of his style and a hallmark of the Baroque period. After c. 1600
he received many commissions, including the monumental The Deposition of Christ (1602-04) and Death of the Virgin (1605-06), which was refused by the Carmelites because of the Virgin’s plebeian fea¬ tures, bared legs, and swollen belly.
His reputation and income increased despite harsh criticism and a turbu¬ lent lifestyle. He had an enormous impact on painting throughout Europe.
caravan Group of merchants, pil¬ grims, or travelers journeying together, usually for mutual protec¬ tion, in deserts or other hostile regions. The camel was the most common means of transport. Cara¬ vans have been described since the beginning of recorded history, and they were a major factor in the growth of settlements along their routes. One caravan trail developed into the Silk Road. During the height of caravan travel, which lasted until the 19th century, a single caravan of Muslim pilgrims journeying from Cairo and Damascus to Mecca might employ as many as 10,000 camels.
caravansary \,kar-9-'van-s3-re\ or caravanserai \,kar-3-'van-s9- ,ri\ Public building used for sheltering caravans and other travelers in the Middle East. The structure is quadrangular in form and enclosed by a massive wall that has small windows near the top and a few narrow air holes near the bottom. The central court, surrounded by an arcade and storerooms, is usually large enough to contain 300-400 camels. It is open to the sky and has a well with a fountain basin in its center. There are rooms upstairs for lodging.
caraway Dried fruit, commonly called the seed, of Carum carvi, a biennial herb of the parsley family. Native to Europe and western Asia, it has been cultivated since ancient times. It has a distinctive aroma and a warm, slightly sharp taste. It is used as a seasoning, and the oil is used to flavor alcoholic beverages and as a medicine.
carbamide See urea
carbide Inorganic compound, any of a class of chemical compounds in which carbon is combined with a metal or semimetallic element. The nature of the second element (its position in the periodic table) determines the carbide’s type of bonding and its properties. Calcium carbide is use¬ ful as a source of acetylene. Carbides of tungsten, silicon (see Carborun¬ dum), and boron, called refractory carbides, are extremely hard, remain stable when heated, and have a high melting point and chemical resis¬ tance. They are used as abrasives and in cutting tools, as furnace linings, and in other high-temperature applications. Iron carbide (cementite) is an important constituent of steel and cast iron.
carbine Light, short-barreled rifle. The first carbines, from the muzzle¬ loading muskets of the 18th century to the lever-action repeaters of the 19th, were chiefly cavalry weapons or saddle firearms for mounted fron¬ tiersmen. During World War II carbine versions of standard bolt-action or semiautomatic infantry rifles were carried by some officers, artillerymen, and other specialists. Carbine versions of modern assault rifles (such as the Russian AK-47 or the U.S. Ml 6 rifle) are intended for close-quarter fighting, partly replacing the submachine gun. Carbine versions of hunting and target rifles are also made.
carbohydrate Any member of a very abundant and widespread class of natural organic compounds that includes sugars, starch, and cellulose. They are commonly classified as monosaccharides (simple sugars; e.g., glucose, fructose), disaccharides (2-unit sugars; e.g., sucrose, lactose), oli¬ gosaccharides (3-10 or so sugars), and polysaccharides (large molecules with up to 10,000 monosaccharide units, including cellulose, starch, and glycogen). Green plants produce carbohydrates by photosynthesis. In most animals, carbohydrates are the quickly accessible reservoir of energy, and oxidation (see oxidation-reduction) of glucose in tissues supplies energy for metabolism. Many (but by no means all) carbohydrates have the gen-
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The Deposition of Christ, oil on canvas 3y Caravaggio, 1602-04; in the Vati- :an Museum.
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carbolic acid ► carbonation I 333
eral chemical formula C„(H 2 0) n . The carbon (C) atoms are bonded to hydrogen atoms (—H), hydroxyl groups (—OH; see functional group), and carbonyl groups (—C=0), whose combinations, order, and geomet¬ ric arrangement lead to a large number of isomers with the same chemi¬ cal formula but different properties. The class is further enlarged because each isomer has various derivatives: uronic acids, sugars with an oxidized group; sugar alcohols, sugars with a reduced group; glycosides, com¬ pounds of sugars with other molecules containing a hydroxyl group; and amino sugars, sugars with an amino group (see amino acid).
carbolic acid \kar-'ba-lik\ or phenol Vfe-.nol, 'fe-,n6l\ Organic com¬ pound, simplest member of the class of phenols. A colourless liquid with a bland, sweetish odour, it is toxic and caustic. It is a high-volume industrial chemical used chiefly in the manufacture of phenol-formaldehyde resins (see formaldehyde; plastics), epoxy resins, nylon, herbicides, biocides, other synthetic chemicals and pharmaceuticals, and dyes. It is also a solvent and general disinfectant. The phenol coefficient is a number that expresses the germicidal action of a chemical compared with that of phenol.
carbon Nonmetallic chemical element, chemical symbol C, atomic num¬ ber 6. The usual stable isotope is carbon-12; carbon-13, another stable iso¬ tope, makes up 1% of natural carbon. Carbon-14 is the most stable and best known of five radioactive isotopes (see radioactivity); its half-life of approximately 5,730 years makes it useful in carbon-14 dating and radi¬ olabeling of research compounds. Carbon occurs in four known allotropes: diamond, graphite, carbon black (amorphous carbon including coal, coke, and charcoal), and hollow cage molecules called fullerenes. Carbon forms more compounds than all other elements combined; several million car¬ bon compounds are known. Each carbon atom forms four bonds (four single bonds, two single and one double bond, two double bonds, or one single and one triple bond) with up to four other atoms. Multitudes of chain, branched, ring, and three-dimensional structures can occur. The study of these carbon compounds and their properties and reactions is organic chemistry (see organic compound). With hydrogen, oxygen, nitro¬ gen, and a few other elements whose small amounts belie their important roles, carbon forms the compounds that make up all living things: pro¬ teins, CARBOHYDRATES, LIPIDS, and NUCLEIC ACIDS. BIOCHEMISTRY is the Study of how those compounds are synthesized and broken down and how they associate with each other in living organisms. Organisms consume car¬ bon and return it to the environment in the carbon cycle. Carbon dioxide, produced when carbon is burned and from biological processes, makes up about 0.03% of the air, and carbon occurs in Earth’s crust as carbonate rocks and the hydrocarbons in coal, petroleum, and natural gas. The oceans contain large amounts of dissolved carbon dioxide and carbonates.