Britannica Concise 2005

Nagyatad

Szigetvar^

Kecskemet

Bekescsaba

1 aks < Ttainasi Szekszard

Kalocsa

. \ Oroshazaj ■ ■

Szeged Hodmezovasarhely

YUGOSLAVIA

BOSNIA AND HERZEGOVINA

© 2002 Encyclopaedia Britannica, Inc.

official). Religion: Christianity (mostly Roman Catholic; also Protestant). Cur¬ rency: forint. The Great Alfold (Great Hun¬ garian Plain), with fertile agriculture land, occupies nearly half of the country. Hunga¬ ry’s two most important rivers are the Danube and the Tisza. Lake Bala¬ ton, in the Transdanubian highlands, is the largest lake in central Europe. Forests cover nearly one-fifth of the land. Hungary is one of the more prosperous countries of eastern Europe and a major world producer of bauxite. A conversion from a socialist to a free-market economy was begun in the late 1980s. Hungary is a multiparty republic with one leg¬ islative house; the chief of state is the president, and the head of govern¬ ment is the prime minister. The western part of the country was incorporated into the Roman Empire in 14 bc. The Magyars, a nomadic people, settled in the Great Alfold in the late 9th century. Stephen I, crowned in 1000, Christianized the country and organized it into a strong and independent state. Invasions by the Mongols in the 13th century and by the Ottoman Empire in the 15th century devastated the country, and by 1568 the territory of modern Hungary was divided into three parts: Royal Hungary had fallen to the Habsburgs; Transylvania had gained autonomy in 1566 under the Ottoman Turks; and the central plain remained under Ottoman control until the late 17th century, when the Austrian Habsburgs took over. Hungary declared its independence from Austria in 1849, and in 1867 the Dual Monarchy of Austria-Hungary was established. Its defeat in World War I (1914-18) resulted in the dismem¬ berment of Hungary, leaving it only those areas in which Magyars pre¬ dominated. In an attempt to regain some of this lost territory, Hungary cooperated with the Germans against the Soviet Union during World War II (1939-45). After the war a pro-Soviet provisional government was established, and in 1949 the Hungarian People’s Republic was formed. Opposition to this Stalinist regime broke out in 1956 but was suppressed (see Hungarian Revolution). Nevertheless, from 1956 to 1988 communist Hungary grew to become the most tolerant of the Soviet-bloc nations of Europe. It gained its independence in 1989 and soon attracted the largest amount of direct foreign investment in eastern and central Europe. It joined NATO in 1999 and the European Union in 2004.

Hunkar jskelesi. Treaty of (1833) Alliance between the Ottoman Empire and Russia, signed at the village of Hunkar iskelesi (Unkiar Ske- lessi), near Istanbul. In return for Russian military aid, the Ottoman sul¬ tan, Mahmud II, agreed to a secret article in their mutual defense treaty that closed the Dardanelles Strait to any foreign vessels of war except those of Russia. The treaty made the Ottoman Empire a virtual protector¬ ate of Russia. When other countries became suspicious of the agreement, Russia abandoned its Dardanelles privileges in 1841.

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Hunkers and Barnburners ► Huntington I 911

Hunkers and Barnburners Two factions of the New York state Democratic Party in the 19th century. The party split over slavery in the 1840s. The conservative Hunkers (so called by their opponents as those who “hunkered” or “hankered” after political office), led by William Marcy, favoured the annexation of Texas and denounced antislavery agi¬ tation. The radical and reformist Barnburners (so called by their oppo¬ nents as those who burned the bam to get rid of the rats), led by Martin Van Buren, opposed slavery’s extension into new territories. At the 1848 Democratic national convention, the Barnburners joined the Free Soil Party, nominating Van Buren for president. In the 1850s some Barnburn¬ ers returned to the Democratic Party while others joined the new Repub¬ lican Party.

Hunt, H(aroldson) L(afayette) (b. Feb. 17, 1889, Ramsey, Ill., U.S.—d. Nov. 29, 1974, Dallas, Texas) U.S. oilman. Hunt purchased a tract of land in eastern Texas in 1930 that became one of the richest oil¬ fields in the U.S. He continued his shrewd investments through his Hunt Oil Co. (founded 1936), which grew into the largest independent oil and gas producer in the country. In the 1960s his company exploited vast oil deposits in Libya. He also invested in publishing, cosmetics, pecan farm¬ ing, and health food. He promoted his ultraconservative views on his own radio programs and newspaper column in the 1950s. Two of his sons, N. Bunker and W. Herbert, tried unsuccessfully to corner the world silver market in 1980, causing its near collapse.

Hunt, R. Timothy (b. Feb. 19, 1943, Neston, Cheshire, Eng.) British scientist. After receiving a Ph.D. from the University of Cambridge in 1968, he conducted research at the Albert Einstein College of Medicine in New York and in 1990 joined the Imperial Cancer Research Fund (now Cancer Research UK) in London. In the early 1980s, using sea urchins, he discovered cyclins, proteins that play a key role in regulating different phases of the cell cycle. His work led to the discovery of cyclins in humans and proved important in the field of tumour diagnostics. Hunt shared a Nobel Prize with Leland H. Hartwell and Sir Paul M. Nurse in 2001.

Hunt, Richard Morris (b. Oct. 31, 1827, Brattleboro, Vt., U.S.—d. July 31, 1895, Rewport, R.I.) U.S. architect. He studied in Europe from 1843 to 1854, becoming the first U.S. architecture student at the Ecole des Beaux-Arts in Paris. He returned to the U.S. to establish the Beaux- Arts style there. His work was eclectic, ranging from ornate early French Renaissance to monumental Classicism to a picturesque villa style. He worked on the extension of the U.S. Capitol and designed the Tribune building in New York City (1873; since destroyed) and the facade of the Metropolitan Museum of Art (1900-02), also in New York. Among the mansions he designed for the new commercial aristocracy is the Break¬ ers in Newport, R.I. (1892-95), which was created in an opulent Renais¬ sance style for the Vanderbilts. Hunt was a founder of the American Institute of Architects.

Hunt, William Holman (b. April 2, 1827, London, Eng.—d. Sept. 7, 1910, London) British painter and cofounder of the Pre-Raphaelite Broth¬ erhood. He attended the Royal Academy schools and achieved his first public success with The Light of the World (1854). His paintings are char¬ acterized by hard colour, minute detail, and an emphasis on moral or social symbolism; their moral earnestness made them extemely popular in Vic¬ torian England. He spent two years in Syria and Palestine painting bib¬ lical scenes, such as The Scapegoat (1855), depicting the outcast animal on the shores of the Dead Sea. His autobiographical Pre-Raphaelitism and the Pre-Raphaelite Brotherhood (1905) is the basic sourcebook of the movement.

Hunter, John (b. Feb. 13, 1728, Long Calderwood, Lanarkshire, Scot.—d. Oct. 16, 1793, London, Eng.) British surgeon. He never attempted to become a medical doctor but assisted in the preparation of dissections for a course of anatomy taught by his brother William Hunter. In the early 1770s he began giving his own lectures on surgery, and in 1776 he was named surgeon extraordinary to George III. He carried out many highly diverse and important studies in comparative biology, anatomy, physiology, and pathology and is considered the founder of pathological anatomy in Britain. He was an important influence on Edward Jenner.

Hunter, William (b. May 23, 1718, Long Calderwood, Lanarkshire, Scot.—d. March 30, 1783, London, Eng.) British obstetrician, educator, and medical writer. The brother of John Hunter, he studied medicine at the University of Glasgow and became a licensed physician in London in 1756. He introduced the French practice of providing individual medi¬

cal students with cadavers for dissection to Britain. After 1756 his medi¬ cal practice was devoted principally to obstetrics; he became the most successful specialist of his day and was made physician extraordinary to Queen Charlotte in 1762. His work did much to remove obstetrics from the purview of midwives and establish it as an accepted branch of medi¬ cine.

Hunter River River, eastern New South Wales, Australia. Rising in the Mount Royal Range of the Eastern Highlands, it flows southwest through the Glenbawn Reservoir and past Denman. There, joined by its major tributary, the Goulburn River, the Hunter turns southeast, entering the Tas¬ man Sea at Newcastle after a course of 287 mi (462 km). Its estuary forms one of the state’s largest harbours.

Hunters' Lodges Secret organization of Canadian rebels and U.S. adventurers dedicated to freeing Canada from British colonial rule. It was formed after the failure of the 1837 rebellion and was concentrated in the northern U.S. border states. In 1838 two attempts to invade Upper Canada (now Ontario) were stopped by local British Canadian militia. Minor bor¬ der raids continued until Pres. Martin Van Buren ordered the lodges dis¬ banded in accordance with U.S. neutrality laws.

hunting Pursuit of game animals, principally as sport. To early humans hunting was a necessity, and it remained so in many societies until recently. The development of agriculture made hunting less necessary as a sole life support, but game was still pursued in order to protect crops, flocks, or herds, as well as for food. Weapons now commonly used in hunting include the rifle, shotgun, and the bow and arrow, and methods include stalking, still-hunting (lying in wait), tracking, driving, and call¬ ing. Dogs are sometimes employed to track, flush, or capture prey. In Europe much of the land once hunted upon was owned by the aristocracy, and gamekeepers were employed to regulate the amount of game that could be hunted in a given area. By the 1800s the land hunted upon was not or had never been privately owned, and there began to develop a “tragedy of the commons,” in that no one hunter had any motive to limit the number of animals killed; certain species were hunted to, or very close to, extinction. To counter this development, ethical codes were established that give the quarry a fair chance to escape; attempts were made to mini¬ mize the suffering of wounded game; and game laws, licensing, and lim¬ ited hunting seasons were established to protect game stocks. For instance, a modem license may authorize a hunter to kill only two deer during the brief season for deer, and he or she must present a kill to a game warden who will then document and tag the animal. There are often penalties and fines for being found with an animal that is not so marked.

hunting and gathering society Any human society that depends on hunting, fishing, or the gathering of wild plants for subsistence. Until c. 8,000 years ago, all peoples were foragers of wild food. Many forag¬ ing peoples continued to practice their traditional way of life into the 20th century, but today all such peoples have developed extensive contacts with settled groups. In the traditional hunting-and-gathering society, social groups were small, usually made up of either individual family units or a number of related families collected together in a band. The diet was well balanced and ample, and food was shared. The men usually did the hunt¬ ing while the women gathered plants and did most domestic chores. The remainder of the time was spent on social and religious activities.

Huntington, Collis P(otter) (b. Oct. 22, 1821, Harwinton, Conn., U.S.—d. Aug. 13, 1900, Raquette Lake, N.Y.) U.S. railroad magnate. He worked as a peddler before becoming a prosperous merchant in Oneonta, N.Y. In the gold rush year of 1849, he moved to Sacramento, Calif., and joined Mark Hopkins in a firm that specialized in miners’ supplies. In the late 1850s he became interested in a plan to link California with the east¬ ern U.S. by rail. In 1861 he joined Hopkins, Leland Stanford, and Charles Crocker (1822-1888)—a group later known as the “Big Four”—to form the Central Pacific Railroad. During its construction (1863-69), Hunting- ton lobbied for the company in the east, securing financing and favour¬ able legislation from the federal government. In 1865 the Big Four formed the Southern Pacific Railroad. In 1869 Huntington bought the Chesapeake and Ohio Railway, which he later extended to link with the Southern Pacific, forming the first transcontinental railroad. He became president of the Southern Pacific-Central Pacific system in 1890.

Huntington, Samuel P(hillips) (b. April 18, 1927, New York, N.Y., U.S.) U.S. political scientist. After receiving a doctorate from Harvard University, he spent most of his career teaching at Harvard, specializing in defense and international affairs. He has been a consultant to many

© 2006 Encyclopaedia Britannica, Inc.

912 I Huntington Beach ► Hurston

government agencies. Among his many books are Political Order in Changing Societies (1968), in which he suggested that developing coun¬ tries are not always likely to create liberal-democratic institutions, and Clash of Civilizations and the Remaking of the World Order (1996), in which he predicted conflicts between the world’s major cultures in the post-Cold War era.

Huntington Beach City (pop., 2000: 189,594), southwestern Califor¬ nia, U.S. Located on the Pacific coast, it was first called Shell Beach and after its subdivision (1901) was known as Pacific City. To encourage its promotion as a seaside resort, it was renamed Huntington Beach for the railroad magnate Henry E. Huntington. Its major economic assets are oil wells and refineries.

Huntington chorea Relatively rare, hereditary neurological disease that is characterized by irregular and involuntary movements of the muscles. Huntington chorea is caused by a genetic mutation that causes degeneration of neurons in a part of the brain that controls movement. Symptoms usually appear between ages 35 and 50. They begin with occa¬ sional jerking or writhing movements, which are absent during sleep, and progress to random, uncontrollable, and often violent twitchings and jerks. Symptoms of mental deterioration begin later and include memory loss, dementia, bipolar disorder, or schizophrenia. There is no effective therapy or cure, and the disease invariably proves fatal. A child of a person with Huntington chorea has a 50% chance of developing the disease.

Huntsman, Benjamin (b. 1704, Holland—d. June 21, 1776, Shef¬ field, Yorkshire, Eng.) British inventor of the crucible process. A clock- maker and instrument maker, Huntsman opened a plant in Sheffield c. 1740, where he produced steel for clock and watch springs. His new pro¬ cess yielded cast steel more uniform in composition and freer from impu¬ rities than any previously produced. Sheffield steelmakers used the crucible process to achieve worldwide dominance in the production of tool and other high-quality steels.

Huntsville City (pop., 2000: 158,216), northern Alabama, U.S. Origi¬ nally called Twickenham, it was the first community in Alabama to be granted a city charter, in 1811. It was the site of Alabama’s first consti¬ tutional convention (1819) and served briefly as the state capital. Settled around Big Spring, it is a commercial centre for hay, cotton, corn, and tobacco. The George C. Marshall Space Flight Center and the University of Alabama in Huntsville (1950) are located there.

Hunyadi \'hu-nyod-e\ Janos (b. 1407?, Hunyad, Transylvania—d. Aug. 11, 1456, Belgrade) Hungarian general. Son of a knight, he saw military service under King Sigismund. While in Italy he learned new mili¬ tary techniques from Francesco Sforza; returning to southern Hungary, he repelled Turkish attacks (1437-38) and was made governor of Transyl¬ vania. With aid from Venice and the pope, he mounted a campaign against the Turks (1441-43) that broke the Ottoman Empire’s hold on the Bal¬ kan states, though he was defeated in a Turkish counterattack at the Battle of Varna (1444). In 1446 he was elected regent for the young king, Las- zlo V, and he served as governor of the kingdom of Hungary 1446-52. In 1456 he raised the Turkish siege of Belgrade before dying of disease. For stopping the supposedly invincible Turkish armies, he is considered a Hungarian national hero.

Huon \'hyu-3n\ River River, southern Tasmania, Australia. Rising on the slopes of Mounts Wedge, Bowen, and Anne, the Huon flows south and then east to be joined by its tributaries, the Weld and Picton rivers, below Huon Gorge. It passes Huonville at the limit of navigation and enters a wide estuary after a course of 105 mi (170 km), then flows into the D’Entrecasteaux Channel. The river’s lower valley is intensively culti¬ vated, containing the island’s leading apple-growing area; it is also a popular tourist region.

Hupeh See Hubei Hupei See Hubei

hurdling Track-and-field event, a footrace over a series of obstacles called hurdles. Runners must remain in assigned lanes throughout a race, and, though they may knock hurdles down while running over them, they may do so only with a leg or foot, not a hand. Modern hurdlers use a sprinting style between hurdles, display an exaggerated forward lean while clearing the hurdle, and then bring the trailing leg through at nearly a right angle to the body, which enables them to continue forward with¬

out breaking stride after clearing the hurdle. Hurdling distances are 110 m and 400 m for men and 100 m and 400 m for women.

hurdy-gurdy Pear-shaped fiddle, the strings of which are sounded by the rim of a rosined wooden wheel turned by a handle. A row of keys is used to produce the melody by stop¬ ping one or two strings; the remain¬ ing strings sound a constant drone. A hurdy-gurdy-like instrument existed in Europe by the 12th century; it took its present shape in the 13th century.

It has long been associated with street musicians, and it is still played as a folk instrument in Europe. The name is also often used for the bar¬ rel organ, in which a hand crank rotates a barrel inside the case, on which several tunes are encoded, causing a small pipe organ to play.

Hurley, Patrick J(ay) (b. Jan. 8,

1883, Indian Territory, U.S.—d. July 30, 1963, Santa Fe, N.M.) U.S. dip¬ lomat. He began practicing law in Oklahoma in 1908. In World War I he served as a colonel in the American Expeditionary Force. Active in Republican Party politics during the 1920s, he served as U.S. secretary of war under Pres. Herbert Hoover from 1929 to 1933. When the U.S. entered World War II, he was promoted to brigadier general and sent to the Philippines to examine the possibility of relieving U.S. troops on the island of Bataan; he succeeded three times in delivering food and ammu¬ nition to the beleaguered troops there. Throughout the remainder of the war he served as the personal representative of Pres. Franklin D. Roosevelt. As ambassador to China (1944-45), he tried unsuccessfully to reconcile the Nationalists and the communists.

hurling Irish sport resembling both field hockey and lacrosse. It is played between two 15-player teams. The game is mentioned in Irish manuscripts dating back to the 13th century bc. The stick used— a tapered, slightly curved device with a cupped blade at the end—is called a hurley. A point is scored by hitting the ball over the crossbar of the opposing team’s goal¬ posts, and three points are scored by driving it under the crossbar. It is considered the national pastime of Ireland.

Hurok \'hyur-,ak\, Sol(omon Isiaevich) (b. April 9, 1888, Pogar, near Kharkov, Russia—d. March 5, 1974, New York, N.Y., U.S.) Russian- born U.S. impresario. He went to the U.S. in 1905 and in 1913 inaugu¬ rated the concert series Music for the Masses, which led to his representing many famous eastern European artists when they toured abroad, including Feodor Chaliapin, Mischa Elman, Anna Pavlova, and Artur Rubinstein.

Huron See Wyandot

Huron, Lake Lake, U.S. and Canada. The second-largest of the Great Lakes of North America, it is bounded by Michigan and Ontario, and is about 206 mi (330 km) long with an area of 23,000 sq mi (59,570 sq km). Inflow comes from Lake Superior, Lake Michigan, and numerous streams; the lake discharges at its southern end into Lake Erie. It contains many islands, including Mackinac, and Saginaw Bay indents the Michigan coast. As part of the St. Lawrence Seaway, it supports heavy commercial traffic from April to December. The first of the Great Lakes seen by Europeans, it was explored by the French (1615-79), who named it after the Huron Indians.

hurricane See tropical cyclone

Hurston, Zora Neale (b. Jan. 7, 1891, Notasulga, Ala., U.S.—d. Jan. 28, 1960, Fort Pierce, Fla.) U.S. folklorist and writer. Although she claimed to have been born in 1901 in Eatonville, Fla., she was in fact born in Alabama 10 years earlier, and her family moved to Eatonville when she was a child. She joined a traveling theatrical company, ending up in New York, where she studied anthropology with Franz Boas at Columbia University and became associated with the Harlem Renaissance. She collaborated with Langston Hughes on the play Mule Bone (1931). Her first novel, Jonah’s Gourd Vine (1934), was followed by the contro¬ versial but widely acclaimed Their Eyes Were Watching God (1937). She also wrote an autobiography, Dust Tracks on a Road (1942).

Hurdy-gurdy played by a French lady of fashion, 18th century

H. ROGER-VIOLLET

© 2006 Encyclopaedia Britannica, Inc.

Hurt ► Husserl I 913

Hurt, John (b. Jan. 22, 1940, Shirebrook, Derbyshire, Eng.) British actor. He made his film and stage debuts in 1962. Known as an insight¬ ful character actor, Hurt had notable roles in A Man for All Seasons (1966), The Elephant Man (1980), and Rob Roy (1995). His stage performances include The Dwarfs (1963) and Travesties (1974). On television he por¬ trayed Quentin Crisp in The Naked Civil Servant (1975) and Caligula in the series I, Claudius (1977).

Hus Vhos, 'hus\, Jan or Jan Huss (b. c. 1370, Husinec, Bohemia—d. July 6, 1415, Konstanz) Bohemian religious reformer. He studied and taught at the University of Prague, where he was influenced by John Wycliffe. As rector of the university from 1402, he became leader of a reform movement that criticized the corruption of the Roman Catholic clergy. The movement was threatened when Wycliffe’s teachings were condemned by the church, and Hus’s position was further undermined by his stand in the power struggles among rival popes. He was excommu¬ nicated in 1411 but continued to preach. Renewed sale of indulgences by the antipope John XXIII earned Hus’s criticism, which in turn led to a revival of the case of heresy against him. He was invited to the Council of Constance to explain his views; though promised safe conduct, he was arrested, tried for heresy, and burned at the stake. His writings were impor¬ tant in the development of the Czech language as well as in the theology of church reform, and his followers were called Hussites.

Husain, Maqbul Fida (b. Sept. 17, 1915, Pandharpur, Maharashtra state, India) Indian artist. His narrative paintings, executed in a modified Cubist style, can be caustic and funny as well as serious and sombre. His themes—usually treated in series—include topics as diverse as Mohan¬ das K. Gandhi, Mother Teresa, the Ramayana, the Mahabharata, the Brit¬ ish raj, and motifs of Indian urban and rural life. One of the most celebrated and internationally recognized Indian artists of the 20th cen¬ tury, he has also received recognition as a printmaker, photographer, and fimmaker.

Husak \'h(y)u-,sak\, Gustav (b. Jan. 10, 1913, Bratislava, Slvk., Austria-Hungary—d. Nov. 18, 1991, Bratislava, Czech.) Leader of Czechoslovakia (1969-89). He helped direct the antifascist Slovak national uprising of 1944, and after the war he began a career as a gov¬ ernment official and Communist Party functionary. He became a deputy premier of Czechoslovakia under Alexander Dubcek. When Dubcek was deposed by Soviet forces, Husak was installed as first secretary of the Communist Party (1969). He reversed Dubcek’s reforms and purged the party of its liberal members. He became president in 1975. When com¬ munist rule collapsed in 1989, he resigned as president.

Husayn, Saddam See Saddam Hussein

Husayn ibn 'All (b. c. 1854, Constantinople, Ottoman Empire—d. 1931, Amman, Transjordan) Sharif of the Hashimite line, Ottoman- appointed emir of Mecca (1908-16), and self-proclaimed king of the Arabs (1916-24). His claim to be the new caliph (1924) led to a short and unsuccessful war against Ibn Sa'Od. Husayn was exiled to Cyprus. One of his sons, ‘Abdullah, became king of Transjordan (present-day Jordan); another became king of Syria and later Iraq as Faysal I.

Husayn ibn Al! Vhu-'san-.ib-on-a-'leV al- (b. January 626, Medina, Hejaz, Arabian Peninsula—d. Oct. 10, 680, Karbala, Iraq) Muslim politi¬ cal and religious leader. He was the grandson of the Prophet Muhammad. After the assassination of his father, the fourth caliph, 'All ibn AbI Taub, he accepted the rule of the first caliph of the Umayyad dynasty, Mu'awiyah I. He refused, however, to acknowledge the succession of the latter’s son, YazId I, and instead accepted an invitation to travel to Iraq in order to lead a revolt against the Umayyads. He, along with a small entourage of fam¬ ily and followers, was intercepted by the Umayyads and killed at the Battle of Karbala’. He is viewed by ShTite Muslims as the prototypical martyr, and his death became a central theme of later Shfite theology and is commemorated annually during the holy festival of c Ashura\

Husayn! \hu-‘sa-ne\, Amin al- (b. 1897, Jerusalem, Palestine, Otto¬ man Empire—d. July 4, 1974, Beirut, Leb.) Palestinian nationalist leader and grand mufti of Jerusalem (1921-37). In 1921 the British appointed him mufti and named him president of the newly created Supreme Mus¬ lim Council. In 1936 Arab groups formed the Arab High Committee, with al-Husaynl as chairman, demanding an end to Jewish immigration to Pal¬ estine. The British forced him out in 1937, and he went to Lebanon; he spent World War II (1939—45) in Germany and fled to Egypt afterward.

Husaynid \hu-'sa-n3d\ dynasty Ruling dynasty of Tunisia (1705- 1957). The dynasty was founded by an officer of the Ottoman Empire, al-Husayn ibn ‘All. He was allowed to rule autonomously and made trea¬ ties with European powers. European pressure led later Husaynid rulers to suppress piracy (1819), abolish slavery, and ease restrictions on Jews (1837-55). When Tunisia became a French protectorate in 1883, Husaynid rulers became mere figureheads. The monarchy was abolished when Tunisia gained its independence in 1957.

hussar \ha-'zar\ Member of a European light-CAVALRY unit used for scout¬ ing, modeled on the 15th-century Hungarian light-horse corps. The bril¬ liantly coloured Hungarian hussar’s uniform was imitated in other European armies; it consisted of a busby (high cylindrical cloth cap), a jacket with heavy braiding, and a dolman (loose coat worn hanging from the left shoulder). Several hussar regiments of the British army were con¬ verted from light dragoons in the 19th century; they survive today as armoured units.

Hussein \hu-'san\ in full Hussein ibn Talal (b. Nov. 14, 1935, Amman, Transjordan—d. Feb. 7,

1999, Amman, Jordan) King of Jor¬ dan (1952-99). Educated in Britain, he succeeded his father, King Talal, while still in his teens. His country’s precarious geographic and economic position and the many Palestinians living there (whom he, unlike other Arab rulers, offered citizenship and a passport) forced him to chart a cau¬ tious course in international rela¬ tions. Though he earned on secret talks with all Israeli leaders except Menachem Begin, he joined other Arab nations against Israel in the Six- Day War (1967). When the Jordan- based Palestine Liberation Organiza¬ tion (PLO) threatened his reign after defeat in that conflict, Hussein expelled it (1971). Thereafter he sought to repair relations with the PLO without unduly antagonizing Israel or the U.S. He surrendered Jor¬ dan’s claim to the West Bank in 1988, ceding it to the PLO. He consid¬ ered his 1994 peace treaty with Israel his crowning achievement.

Husserl Vhu-so-roL, Edmund (b. April 8, 1859, Prossnitz, Moravia, Austrian Empire—d. April 27, 1938,

Freiburg im Breisgau, Ger.) German philosopher, founder of phenomenol¬ ogy. He received a doctoral degree in mathematics at the University of Vienna in 1882. From 1883 to 1886 he studied with Franz Brentano, whose descriptive psychology prompted Husserl to reflect on the psychological sources of basic math¬ ematical concepts. He lectured at the University of Halle from 1887 to 1901. His Logical Investigations (1901) employed a method he called “phenomenological,” consisting of an analysis of experienced reality exactly as it presents itself to con¬ sciousness. He developed the method in Ideas (1913) and other works written while teaching at the University of Gottingen (1901-16); its fundamental methodological principle was what he called phenomeno¬ logical, or “eidetic,” reduction, which focuses the philosopher’s attention on uninterpreted experience and the quest, thereby, for the essences of things. Because it is also reflection on the functions by which essences become conscious, the reduction reveals the ego for which everything has meaning. In 1916 Husserl accepted a professorship at the University of Freiburg, where Martin Heidegger was one of his students; when Husserl retired in 1928, Heidegger succeeded to his chair. After 1933, when the

Edmund Husserl, c. 1930.

ARCHIV FUR KUNST UND GESCHICHTE, BERUN

© 2006 Encyclopaedia Britannica, Inc.

914 I Hussite ► Huxley

Nazis seized power in Germany, Husserl was excluded from the univer¬ sity because of his Jewishness. His work was enormously influential in the subsequent development of Continental philosophy and in other fields, including the social sciences and psychoanalytic theory.

Hussite Vho-.slt, 'hu-,slt\ Member of a group of 15th-century Bohemian religious reformers, followers of Jan Hus. After Hus’s death in 1415, the Hussites broke with Rome. In addition to giving communion in both bread and wine, they supported freedom of preaching, poverty of the clergy, civil punishment of notorious sinners, and expropriation of church prop¬ erty. Many were nobles and knights, and a papal crusade against them failed in 1431. During peace negotiations in 1433 the Hussites split into two factions, the moderate Utraquists and the radical Taborites. The Utraquists joined the Catholics and defeated the Taborites at the battle of Lipany in 1434; they survived schisms until 1620, when they were absorbed by the Catholics. Another segment of Hussites, Unitas Fratrum, set up an independent organization in 1467 and lasted until the Counter- Reformation. In 1722 a group of Hussites fled Moravia and settled on the estate of Count Nikolaus Ludwig von Zinzendorf (1700-1760) in Sax¬ ony, establishing the community of Herrnhut and founding the Moravian CHURCH.

Huston Vhyii-stonV, John (b. Aug. 5, 1906, Nevada, Mo., U.S—d. Aug. 28, 1987, Middletown, R.I.) U.S. film director and screenwriter. The son of Walter Huston, he was briefly a boxer, a Mexican cavalry officer, and a reporter before becoming a scriptwriter. His first work as a director, The Maltese Falcon (1941), began an illustrious career studded with film clas¬ sics: The Treasure of the Sierra Madre (1948, Academy Awards for best director and screenplay), Key Largo (1948), The Asphalt Jungle (1950), The African Queen (1951), Moulin Rouge (1952), The Night of the Iguana (1964), The Man Who Would Be King (1975), Prizzi’s Honor (1985), and The Dead (1987). He wrote screenplays for many of his own films and for others such as Jezebel (1938), Juarez (1939), and High Sierra (1941). He also worked as an actor, notably in Chinatown (1974). His daughter Anjelica (b. 1951) was an accomplished actress, earning an Academy Award for her performance in Prizzi’s Honor (1985).

Huston, Walter orig. Walter Houghston (b. April 6, 1884, Tor¬ onto, Ont., Can.—d. April 7, 1950, Beverly Hills, Calif., U.S.) Canadian- born U.S. actor. He made his stage debut in his native Toronto in 1902 and his New York debut in 1905. He and his second wife were a popular vaudeville song-and-dance team (1909-24). On Broadway he won praise in Desire Under the Elms (1924), Dodsworth (1934; film, 1936), and Knickerbocker Holiday (1938), in which he sang “September Song.” He appeared in over 50 films, including Abraham Lincoln (1930), Rain (1932), and The Treasure of the Sierra Madre (1948, Academy Award), directed by his son John Huston.

Hutchins, Robert Maynard (b. Jan. 17, 1899, Brooklyn, N.Y., U.S.—d. May 17, 1977, Santa Barbara, Calif.) U.S. educator and foun¬ dation president. He attended Oberlin College and graduated from Yale University (A.B., 1921) and Yale Law School (LL.B., 1925), becoming dean of Yale Law School in 1927. At the University of Chicago as presi¬ dent (1929-45) and chancellor (1945-51), he encouraged liberal educa¬ tion based on the study of the great books of the Western tradition, deplored any tendency toward vocationalism, and dismantled the inter¬ collegiate athletic program. Hutchins later headed various foundations, including the Ford Foundation. He served as chairman of the board of editors of Encyclopedia Britannica (1943-74) and edited the 54-volume Great Books of the Western World (1952). He expounded his views on education in Higher Learning in America (1936).

Hutchinson, Anne orig. Anne Marbury (baptized July 20, 1591, Alford, Lincolnshire, Eng.—d. August or September 1643, Pelham Bay, N.Y.) Anglo-American religious leader. In 1612 she married William Hutchinson, and they followed John Cotton to the Massachusetts Bay Colony in 1634. She organized weekly meetings of Boston women to dis¬ cuss recent sermons and to express their own theological views. Before long, ministers and magistrates were attracted to her sessions, at which she criticized the narrow Puritan orthodoxy and espoused a “covenant of grace.” Her opponents accused her of believing that God’s grace had freed Christians from the need to observe established moral precepts. Tried for “traducing the ministers,” she was sentenced to banishment; refusing to recant, she was excommunicated. In 1638 she and her husband established a colony at Aquidneck Island, which became part of Rhode Island.

Hutchinson, Thomas (b. Sept. 9, 1711, Boston, Mass.—d. June 3, 1780, London, Eng.) American colonial administrator. The son of a wealthy Boston merchant, he pursued business ventures before serving in local and provincial legislatures (1737—49) and as a delegate to the Albany Congress. He served as lieutenant governor (1758-71) and as chief jus¬ tice of the state Superior Court (1760-69). As governor (1771-74), he strictly enforced British rule. After he was accused of initiating the hated Stamp Act, a mob attacked his home, and he barely escaped with his life. His insistence that a shipment of tea be landed in Boston led to the Bos¬ ton Tea Party. He was replaced as governor by Gen. Thomas Gage.

Hutchinson Family U.S. singing group, significant figures in the development of a native popular music tradition. Bom and raised in Mil¬ ford, N.H., the Hutchinson brothers Judson (1817-59), John (1821-1908), and Asa (1823-84) and sister Abby (1829-92) formed a quartet and began giving concerts around New England in 1841. In contrast to the prevail¬ ing sentimental and minstrel songs of the period, their songs embraced political causes, including woman suffrage, prohibition of alcohol, and opposition to the Mexican War. They sang at many antislavery rallies, including a Boston rally that drew 20,000 people. With some members replaced by other family members, the family continued to tour into the 1880s.

Hutterite \ , h3-t3- l rlt\ Member of the Hutterite Brethren, an Anabaptist sect that takes its name from its Austrian founder, Jakob Hutter, who was burned as a heretic in 1536. His followers modeled themselves on the early church in Jerusalem by holding their goods in common. Persecuted in Moravia and the Tirol, they moved eastward to Hungary and the Ukraine. In the 1870s many emigrated to the U.S. and settled in South Dakota. The society still exists in the western U.S. and Canada, where it has colonies of 60-150 members, who operate collective farms. Hutter- ites are pacifists who take no part in politics and remain separate from outside society.

Hutton, James (b. June 3, 1726, Edinburgh, Scot.—d. March 26, 1797, Edinburgh) Scottish geologist, chemist, and naturalist. After short careers in law and medicine, he followed his interest in chemistry and developed an inexpensive manufacturing process for sal ammoniac. He settled in Edinburgh (1768) to pursue a life of science. In two papers presented in Edinburgh in 1785 (published 1788), he elaborated his theory of unifor- mitarianism. Its ability to explain the Earth’s geologic processes without reference to the Bible and its emphasis on an immensely long, cyclical process of erosion, deposition, sedimentation, and volcanic upthrust were revolutionary.

Hutu Bantu-speaking people of Rwanda and Burundi, with a large refu¬ gee population in Congo (Kinshasa). Numbering about 9.5 million, the Hutu comprise the vast majority in both Rwanda and Burundi but were traditionally subject to the Tutsi, who under German and Belgian colonial regimes succeeded in cultivating a lord-vassal relationship. The two cul¬ tures are deeply intertwined; both speak Rwanda and Rundi and adhere to similar religious beliefs (traditional and Christian). The Tutsi remained dominant in Rwanda until 1961, when the Hutu expelled most of them and took over the government. After an unsuccessful Hutu coup attempt in Burundi in 1965, that country’s Hutu remained subordinate under a Tutsi-dominated military government. Violent clashes occurred in Burundi in 1972, 1988, and 1993 and in Rwanda in 1990 and 1994-96, the later including a Hutu-initiated genocidal campaign in which more than a million people were killed and 1-2 million fled to refugee camps in Zaire (now Congo) and Tanzania.

Huxley, Aldous (Leonard) (b.

July 26, 1894, Godaiming, Surrey,

Eng.—d. Nov. 22, 1963, Los Ange¬ les, Calif., U.S.) British novelist and critic. Grandson of T.H. Huxley and brother of Julian Huxley, he was par¬ tially blind from childhood. He is known for works of elegant, witty, pessimistic satire, including Crome Yellow (1921) and Antic Hay (1923), which established him as a major

novelist, and Point Counter Point ..

(1928). The celebrated Brave New

© 2006 Encyclopaedia Britannica, Inc.

Huxley ► Hyderabad I 915

World (1932) is a nightmarish vision of a future society that expresses his distrust of trends in politics and technology. Beginning with Eyeless in Gaza (1936), his works reveal a growing interest in Hindu philosophy and mysticism. Later works include the nonfiction The Devils of Loudun (1952) and The Doors of Perception (1954), about his experiences with hallucinogens.

Huxley, Sir Julian (Sorell) (b. June 22, 1887, London, Eng.—d. Feb. 14, 1975, London) British biologist, philosopher, and author. He was a grandson of T.H. Huxley and brother of Aldous Huxley. His research on hormones, developmental processes, ornithology, and ethology influenced the modern development of embryology, classification, and studies of behaviour and evolution. He applied his scientific knowledge to social and political problems, formulating an ethical theory of “evolutionary humanism.” His many books written for the general public, including The Science of Life (1931; with H.G. Wells), were widely read. He served as the first director-general of UNESCO (1946-48).

Huxley, T(homas) H(enry) (b. May 4, 1825, Ealing, Middlesex, Eng.—d. June 29, 1895, Eastbourne, Sussex) British biologist. The son of a schoolmaster, he earned a medical degree. After working as a sur¬ geon on a surveying expedition in the South Pacific (1846-50), during which he carried out extensive studies of marine organisms, he taught for many years at the Royal School of Mines in London (1854-85). In the 1850s he established his reputation with his important papers on animal individuality, certain mollusks, the methods of paleontology, the methods and principles of science and science education, the structure and func¬ tions of nerves, and the vertebrate skull. He was one of the earliest and strongest supporters of Darwinism; his 1860 debate with Bishop Samuel Wilberforce gained widespread attention. In the 1860s Huxley did valu¬ able work in paleontology and classification, especially classification of birds. Later in life he turned to theology; he is said to have coined the word agnostic to describe his views.

Few scientists have been as influen¬ tial over such a wide field of scien¬ tific development and as effective in the total movement of thought and action within their own generation.

Huygens Vhl-ganz, 'hoi-gonzV Christiaan or Christian Huyghens (b. April 14, 1629, The Hague—d. July 8, 1695, The Hague)

Dutch mathematician, astronomer, and physicist. He was the first to use a pendulum to regulate a clock (1656). He invented a method of grinding and polishing telescope lenses, and he used his telescopes to discover the true shape of Saturn’s rings (1659). He developed explana¬ tions of reflection and refraction based on the principle of secondary wave fronts, now called Huygens’ principle. He developed the wave theory of light (1678) and also con¬ tributed to the science of dynamics.

His work on rotating bodies led to solutions of problems involving oscillation of a pendulum and uni¬ form circular motion. He was also the first to determine acceleration due to gravity.

Huysmans \wes-'ma n s\, Joris- Karl orig. Charles-Marie- Georges Huysmans (b. Feb. 5,

1848, Paris, France—d. May 12,

1907, Paris) French Decadent writer.

His early works, influenced by con¬ temporary naturalism, were followed by far more individual and violent works. The first was Down Stream (1882). His best-known novel, A rebours (1884; Against the Grain), relates experiments in decadence by

the bored survivor of a noble line. The controversial and clearly autobio¬ graphical La-bas (1891; Down There) is a tale of 19th-century satanists. His final novels concern his return to Roman Catholicism. He also wrote perceptive art criticism.

Hwang River See Huang River

Hwange Vhwaq-ga\ National Park formerly Wankie \'waq-ke\ National Park National preserve, northwestern Zimbabwe. Located on the Botswana frontier, it was established in 1928 as a game reserve and in 1930 as a national park. The land, with an area of 5,657 sq mi (14,651 sq km), is largely flat, with hardwood forests of mukwa and teak. It is one of Africa’s largest elephant sanctuaries; its abundant wildlife can be observed from platforms overlooking the water holes.

Hwarangdo Vhwa-'raq-'doN Military and philosophical code devel¬ oped in the Korean state of Silla during the 6th century. It formed the basis for training an elite society of young warriors known as the hwarang, who were instrumental in unifying Korea under the Silla dynasty (668- 935). Their moral code, derived from Buddhism and Confucianism, empha¬ sized loyalty to the king, filial piety, faithfulness to friends, courage in battle, and the evil of indiscriminate killing. The hwarang were disbanded during the Choson dynasty (1392-1910), but interest in the code revived in the late 20th century with a style of Korean martial arts known as hwarangdo.

hyacinth Any of the approximately 30 species of bulbous ornamental herbaceous plants that make up the genus Hyacinthus (lily family), native primarily to the Mediterranean region and tropical Africa. The common garden hyacinths are derived from H. orientalis. Most species have nar¬ row, untoothed leaves at the base of the plant and fragrant flowers (usu¬ ally blue, but sometimes pink, white, or other colors in cultivated varieties) borne in a cluster at the top of the leafless stems. See also grape HYACINTH.

Hyacinthus V.hl-o-'sin-thosX In Greek mythology, a young man of great beauty who attracted the love of Apollo. The god killed him accidentally in discus throwing, and from his blood grew the flower hyacinthos (not the modern hyacinth), whose petals were marked with the words AI, AI (“Alas”). His death was celebrated at Amyclae, his native town in Sparta, with an early summer festival known as the Hyacinthia. The festival marked the transition from spring to summer.

Hyades VhI-9- 1 dez\ Open cluster of several hundred stars in the constel¬ lation Taurus. The bright star Aldebaran appeal's to be a member of the cluster but is much closer to Earth than the Hyades, which is about 130 light-years away. Five genuine members of the group are visible to the unaided eye.

hybrid Offspring of parents that differ in genetically determined traits (see genetics). The parents may be of two different species, genera, or (rarely) families. The terms “mongrel” and “crossbreed” refer usually to animals or plants resulting from a cross between two races, breeds, strains, or varieties of the same species. Because of basic biological incompat¬ ibilities, sterile hybrids (those that cannot produce living young) such as the mule (a hybrid between a jackass and a mare) commonly result from crosses between species. Some species hybrids, however, are fertile and can be sources for the formation of new species. Many economically or aesthetically important cultivated plants (e.g., bananas, coffee, peanuts, dahlias, roses, bread wheats, alfalfa, etc.) originated through natural or artificially induced hybridization. Hybridization is important biologically because it increases necessary genetic variation within a species.

Hyde, Edward See Earl of Clarendon

Hyder Ali Vhl-dor-a-'leV (b. 1722, Budikote, Mysore, India—d. Dec. 7, 1782, Chittoor) Muslim ruler of Mysore, in southern India. He organized the first Indian-controlled corps of Indian soldiers armed with Western weapons, obtained a command in the Mysore army, and eventually over¬ threw Mysore’s raja. He conquered neighbouring areas and joined a con¬ federacy with the Nizam 'All Khan and the Marathas against the British. He fought the British for more than a decade, but at the end of his life, recognizing that he could not defeat them, he urged his son to make peace.

Hyderabad City (pop., 2001 prelim.: 3,449,878), capital of Andhra Pradesh state, southern India. Founded by the sultans of Golconda in the 16th century, the town was plundered and destroyed following the Mughal occupation in 1685. In 1724 it became the capital of the independent kingdom of Hyderabad. A walled city, it has many buildings in a blend of

Christiaan Huygens, portrait by C. Netscher, 1671 ; in the Collection Haags Gemeentemuseum, The Hague

COURTESY OF THE COLLECTION HAAGS GEMEENTEMUSEUM, THE HAGUE

Joris-Karl Huysmans, detail of an oil painting by Jean-Louis Forain.

J.E. BULLOZ

© 2006 Encyclopaedia Britannica, Inc.

916 I Hyderabad ► hydrogen

Hindu and Muslim styles. Adjacent Secunderabad grew as a British can¬ tonment, connected to Hyderabad by an embankment 1 mi (1.6 km) long. It is the site of Osmania University (1918) and the University of Hyder¬ abad (1974).

Hyderabad or Haydarabad City (pop., 1998: 1,151,274), Sind province, Pakistan. Located east of the Indus River, it was founded in 1768 by Ghulam Shah Kalhora. It remained the capital of Sind until 1843, when it surrendered to the British and the capital was transferred to Karachi. It is now a communications, commercial, and industrial centre. Notable antiquities include the tombs and palaces of former rulers; characteristic of the city are badgirs (“wind-catchers”) fixed to housetops to catch sea breezes during the hot season.

Hyderabad Vhl-ds-ro-.badV Former princely state, south-central India. Originally part of the kingdom of Golconda, it was brought into the Mughal Empire in 1687. The independent kingdom of Hyderabad was founded by Nizam ul-Mulk in 1724. In 1798 it was placed under British protection, although the nizams (rulers) continued to rule over their princely state. At Indian partition in 1947, the nizam chose to resume Hyderabad’s independent status, but India invaded the state (1948) and took control. The area is now divided among the states of Andhra Pradesh, Karnataka, and Maharashtra.

hydra Any of 20-30 species of freshwater cnidarians (genus Hydra). The POLYP-type body is a thin, usually translucent tube that measures up to slightly more than 1 in. (25 mm) long. Food is ingested and wastes are ejected from the open, tentacled end. Individuals are usually hermaphro¬ ditic (see hermaphroditism). Reproduction by budding is also common. Spe¬ cies differ in colour, tentacle length and number, and gonad position and size. All hydras feed on other small invertebrates (e.g., crustaceans).

hydrangea \hl-'dran-j3\ Any of approximately 23 species of erect or climbing woody shrubs that make up the genus Hydrangea (family Hydrangeaceae). It is native to the Western Hemisphere and eastern Asia. Several species are grown in greenhouses and gardens for their showy, usually ball-like flower clusters. Cultivated varieties of the French hydran¬ gea, or hortensia H. macrophylla, bear large globular flower clusters in various colours; they are the florist’s hydrangeas.

hydraulic jump Sudden change in water level, analogous to a shock wave, commonly seen below weirs and sluice gates where a smooth stream of water suddenly rises at a foaming front. The fact that the speed of water waves varies with wavelength and with amplitude leads to a wide variety of effects. Tidal bores, which may be observed on some estuar¬ ies, are large-scale examples. See also Bernoulli's principle.

hydraulic press Machine consisting of a cylinder fitted with a piston (see piston and cylinder) that uses liquid under pressure to exert a com¬ pressive force upon a stationary anvil or baseplate. The liquid is forced into the cylinder by a pump. The hydraulic press is widely used in indus¬ try for forming metals and for other tasks where a large force is required. It is manufactured in a wide variety of styles and sizes and in capacities ranging from 1 ton (0.9 metric ton) or less to 10,000 tons (9,000 metric tons) or more. See also punch press.

hydraulics Branch of science concerned with the practical applications of fluids, primarily liquids, in motion. It is related to fluid mechanics, which in large part provides its theoretical foundation. Hydraulics deals with such matters as the flow of liquids in pipes, rivers, and channels and their confinement by dams and tanks. Some of its principles apply also to gases, usually when variations in density are relatively small. The scope of hydraulics extends to such mechanical devices as actuators and control systems. See also Bernoulli's principle, Pascal's law, pump.

hydride Vhl-.dridV Inorganic compound of hydrogen with another ele¬ ment. Three common types are differentiated by their bonding. In saline (ionic) hydrides (see ionic bond), the hydrogen is an anion, H - , and behaves like a halogen. Saline hydrides such as sodium hydride (NaH) and calcium hydride (CaH 2 ) react vigorously with water, giving off hydro¬ gen gas (H 2 ), and are used as portable sources of it. Metallic hydrides, such as titanium hydride (TiH 2 ), are alloylike materials (see alloy) with some properties of metals, such as luster and electrical conductivity. Cova¬ lent hydrides (see covalent bond) are mostly compounds of hydrogen and nonmetallic elements; they include water, ammonia, hydrogen sulfide (H 2 S), and methane. In polymeric hydrides, the hydrogen forms bridges

between other atoms (e.g., hydrides of boron and aluminum). Those hydrides give off large amounts of energy when burned and may be use¬ ful as rocket fuels.

hydrocarbon Any of a class of organic compounds composed only of carbon and hydrogen. The carbon atoms form the framework, and the hydrogen atoms attach to them. Hydrocarbons, the principal constituents of petroleum and natural gas, serve as fuels, lubricants, and raw materials for production of plastics, fibres, rubbers, solvents, explosives, and indus¬ trial chemicals. All burn to carbon dioxide and water with enough oxygen or to carbon monoxide without it. The two major categories are aliphatic, with the carbon atoms in straight or branched chains or in nonaromatic rings, and aromatic (see aromatic compound). Aliphatic compounds may be saturated (paraffins) or, if any carbon atoms are joined by double or triple bonds, unsaturated (e.g., olefins, alkenes, alkynes). All but the sim¬ plest hydrocarbons have isomers (see isomerism). Ethylene, methane, acety¬ lene, benzene, toluene, and naphthalene are hydrocarbons.

hydrocephalus N.hl-dro-'se-fo-losV Accumulation of cerebrospinal fluid (CSF) in the ventricles (cavities) of the brain. Hydrocephalus is caused by overproduction of CSF, congenital blockage that prevents drainage (see neural tube defect), or complications of head injuries or infections. Nor¬ mally, CSF circulates through the brain and spinal cord and drains into the circulation. In infants and young children, hydrocephalus causes the brain and skull to enlarge because the fontanels have not yet closed. Without surgery to divert the excess fluid into the blood or abdomen, accumulating fluid eventually compresses the brain, causing convulsions, mental retardation, and death.

hydrochemistry See chemical hydrology

hydrochloric acid or muriatic acid Solution in water of hydrogen chloride (HC1), a gaseous inorganic compound. It is a strong acid, virtu¬ ally completely dissociated (see dissociation) into hydronium cations (H 3 0 + ) and chloride anions (Cl - ), and is corrosive and irritating. The acid reacts with most metals, to produce hydrogen and the metal’s chloride, and with oxides, hydroxides, and many salts. It is used extensively in indus¬ trial processing of metals and concentrating of some ores; in boiler scale removal, food processing, metal cleaning, and pickling; and as a chemi¬ cal intermediate, laboratory reagent, and alcohol denaturant (see ethanol). Hydrochloric acid is present in the stomach’s gastric juice and is involved in the devlopment of peptic ulcers.

hydroelectric power Electricity produced from generators driven by water turbines that convert the energy in falling or fast-flowing water to mechanical energy. Water at a higher elevation flows downward through large pipes or tunnels (penstocks). The falling water rotates turbines, which drive the generators, which convert the turbines’ mechanical energy into electricity. The advantages of hydroelectric power over such other sources as fossil fuels and nuclear fission are that it is continually renew¬ able and produces no pollution. Norway, Sweden, Canada, and Switzer¬ land rely heavily on hydroelectricity because they have industrialized areas close to mountainous regions with heavy rainfall. The U.S., Russia, China, India, and Brazil get a much smaller proportion of their electric power from hydroelectric generation. See also tidal power. See illustration opposite on following page.

hydrogen Lightest chemical element, chemical symbol H, atomic num¬ ber 1. A colourless, odourless, tasteless, flammable gas, it occurs as the diatomic molecule H 2 . Its atom consists of one proton (the nucleus) and one electron; the isotopes deuterium and tritium have an additional one and two nuclear neutrons, respectively. Though only the ninth most abundant element on Earth, it represents about 75% of all matter in the universe. Hydrogen was formerly used to fill airships; nonflammable helium has replaced it. It is used to synthesize ammonia, ethanol, aniline, and metha¬ nol; to treat petroleum fuels; as a reducing agent (see reduction) and to supply a reducing atmosphere; to make hydrogen chloride (see hydro¬ chloric acid) and hydrogen bromide; and in hydrogenation (e.g., of fats). Liquid hydrogen (boiling point -423 °F [-252.8 °C]) is used in scientific and commercial applications to produce extremely low temperatures and as a rocket propellant and a fuel for fuel cells. Combustion of hydrogen with oxygen gives water as the sole product. The properties of most acids, especially in water solutions, arise from the hydrogen ion (H + , also referred to as the hydronium ion, H 3 0 + , the form in which H + is found in a water environment). See also hydride; hydrocarbon.

© 2006 Encyclopaedia Britannica, Inc.

hydrogen bomb ► hydrothermal ore deposit I 917

hydrogen bomb or H-bomb or thermonuclear bomb Weapon whose enormous explosive power is generated by the nuclear fusion of hydrogen isotopes. The high temperatures required for the fusion reaction are produced by detonating an atomic bomb (which draws its energy from nuclear fission). The bomb’s explosion produces a blast that can destroy structures within a radius of several miles, an intense white light that can cause blindness, and heat fierce enough to set off firestorms. It also cre¬ ates radioactive fallout that can poison living creatures and contaminate air, water, and soil. Hydrogen bombs, which may be thousands of times more powerful than atomic bombs, can be made small enough to fit in the warhead of a ballistic missile (see ICBM) or even in an artillery shell (see neutron bomb). Edward Teller and other U.S. scientists developed the first H-bomb and tested it at Enewetak atoll (Nov. 1, 1952). The Soviet Union first tested an H-bomb in 1953, followed by Britain (1957), China (1967), and France (1968). Most modern nuclear weapons employ both fusion and fission.

hydrogen bonding Interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons; such a bond is weaker than an ionic bond or covalent bond but stronger than van der Waals forces. Hydrogen bonds can exist between atoms in different molecules or in parts of the same molecule. One atom of the pair (the donor), generally a fluorine, nitrogen, or oxygen atom, is covalently bonded to a hydrogen atom (—FH, —NH, or —OH), whose electrons it shares unequally; its high electron affinity causes the hydrogen to take on a slight positive charge. The other atom of the pair, also typically F, N, or O, has an unshared electron pair, which gives it a slight negative charge. Mainly through electrostatic attraction, the donor atom effectively shares its hydrogen with the acceptor atom, forming a bond. Because of its extensive hydrogen bonding, water (H 2 0) is liquid over a far greater range of temperatures that would be expected for a molecule of its size. Water is also a good solvent for ionic compounds and many others because it readily forms hydrogen bonds with the solute. Hydrogen bonding between amino acids in a linear protein molecule determines the way it folds up into its functional configuration. Hydrogen bonds between nitrogenous bases in nucleotides on the two strands of DNA (guanine pairs with cytosine, adenine with thymine) give rise to the double-helix structure that is crucial to the transmission of genetic information.

reservoir

A hydro station generates power by the controlled release of water from the reser¬ voir of a dammed river. The flowing water turns a turbine, which powers a genera¬ tor, creating electricity. The voltage is stepped up by a transformer to allow long¬ distance power transmission.

© MERRIAM-WEBSTER INC.

hydrogenation Mil-.dra-jo-'na-shonV Chemical reaction between molecular hydrogen (H 2 ) and another element or a compound, usually in the presence of a catalyst. It may involve adding hydrogen at the sites of double or triple bonds (see bonding) to make them single bonds (i.e., to saturate an unsaturated compound; see saturation), or to aromatic com¬ pounds to make them cyclic hydrocarbons. Edible oils with unsaturated fatty acids are liquid at room temperature; food manufacturers use hydro¬ genation to convert a fraction to saturated fatty acids to make the product more solid. A second type of hydrogenation involves breaking up a com¬ pound (hydrogenolysis, or destructive hydrogenation) and is of great importance in the petroleum industry. Numerous processes in gasoline and petrochemical manufacturing are based on it.

hydrologic \,hl-dr3-'la-jik\ cycle Cycle that involves the continuous circulation of water in the Earth-atmosphere system. Water is transferred from the oceans through the atmosphere to the continents and back to the oceans by means of evaporation, transpiration, precipitation, interception, infiltration, subterranean percolation, overland flow, runoff, and other complex processes. Although the total amount of water within the cycle remains essentially constant, its distribution among the various processes is continually changing.

hydrology Scientific discipline concerned with the waters of the Earth, including their occurrence, distribution, circulation via the hydrologic cycle, and interactions with living things. It also deals with the chemical and physical properties of water in all its phases.

hydrolysis \hl-'dra-ta-s9s\ Chemical reaction in which water (H 2 0 or HOH) and another reactant exchange functional groups to form two prod¬ ucts, one containing the H and the other the OH. In most hydrolyses involving organic compounds, the other reactants and products are neu¬ tral; for example, an ester can be hydrolyzed to form a carboxylic acid and an alcohol. Such reactions are often accelerated by enzymes (as in much of digestion and metabolism in general) or other catalysts. In hydrolyses of compounds with ionic bonds, the nonwater reactants are salts, acids, or bases, participating in dissociation reactions.

hydrometallurgy Extraction of metal from ore by dissolving the metal (as one of its salts) and then recovering it from the solution. The opera¬ tions usually involved are leaching (dissolving in water), commonly with additional agents; separating the waste and purifying the leach solution; and precipitating the metal or one of its pure compounds from the leach solution by chemical or electrolytic means. Though hydro metallurgy originated in the 16th century, its principal development took place in the 20th century. The development of ion exchange, solvent extraction, and other processes now permits more than 70 metallic elements to be pro¬ duced by hydrometallurgy, including most gold, much silver, and large tonnages of copper and zinc.

hydroponics Cultivation of plants in nutrient-enriched water, with or without the mechanical support of an inert medium such as sand or gravel. Fertilizer solution is pumped through the system periodically. As the plants grow, concentration of the solution and frequency of pumping are increased. A wide variety of vegetables and florist crops can be grown satisfactorily in gravel. Automatic watering and fertilizing saves on labor, but installation costs are high and fertilizer solution must be tested fre¬ quently. Yields are about the same as for soil-grown crops.

hydrosphere Discontinuous layer of water at or near the Earth’s sur¬ face. It includes all liquid and frozen surface waters, groundwater held in soil and rock, and atmospheric water vapour. Virtually all of these waters are in constant circulation through the hydrologic cycle. Although the com¬ ponents of the hydrosphere are undergoing continuous change of state and location, the total water budget remains in balance. The components of the hydrosphere have been seriously affected by the water-polluting activi¬ ties of modern society.

hydrostatics Branch of physics that deals with the characteristics of flu¬ ids at rest, particularly with the pressure in a fluid or exerted by a fluid (gas or liquid) on an immersed body. In applications, the principles of hydrostatics are used for problems relating to pressure in deep water (pressure increases with depth) and high in the atmosphere (pressure less¬ ens with altitude).

hydrotherapy External use of water for medical treatment. Wet heat helps relieve pain, improves circulation, and promotes relaxation. Wet cold causes blood vessels to close, reducing swelling and pain after injury. Underwater exercise helps strengthen weak muscles, restore joint motion after injury, clean and heal burned flesh, aid muscle function after stroke, and treat arthritic deformity and pain. Whirlpool baths and showers are also used. Hydrotherapy is usually employed by specialists in physical MEDICINE AND REHABILITATION.

hydrothermal ore deposit Any concentration of metallic minerals formed by the release of solids from hot mineral-laden water (hydrother¬ mal solution). The solutions are thought to arise in most cases from the action of deeply circulating water heated by magma. Another source of heating that may be involved includes energy released by radioactive decay.

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918 I hydroxide ► hypertext

hydroxide Any compound with one or more functional groups made up of one atom each of hydrogen and oxygen, bonded together and acting as the hydroxide anion (OH - ). Hydroxides include the familiar alkalies of laboratory and industrial processes. Those of the alkali metals (lithium, sodium, potassium, rubidium, and cesium), the strongest bases, are the most stable and soluble; those of the alkaline earth metals (calcium, barium, and strontium), also soluble strong bases, are less stable. The hydroxides of most other metals are only slightly soluble but neutralize acids; some are “amphoteric,” reacting with both acids and bases. In compounds in which OH is un-ionized and covalently bonded (e.g., in methanol, CH 3 OH), it is known as a hydroxyl group.

hyena Any of three species of coarse-furred, doglike carnivores (fam¬ ily Hyaenidae) found in Asia and Africa. Actually more closely related to cats than to dogs, they have four toes on each foot, long forelegs, non- retractile claws, and enormously strong jaws and teeth. They live alone or in packs and may be active by night or day. Hyenas are noted for scav¬ enging but will also attack live prey. The spotted, or laughing, hyena, whose calls alternately resemble wailing and maniacal laughter, ranges through much of sub-Saharan Africa. Yellowish or grayish with dark spots, it is about 6.5 ft (1.8 m) long, including the 12-in. (30-cm) tail, and weighs up to 175 lbs (80 kg). It has been known to attack people and even carry off young children.

Hyksos \'hik-,s6s\ Group of mixed Semitic-Asiatics who settled in northern Egypt in the 18th century bc. They seized power c. 1630 bc and ruled Egypt for 108 years thereafter. They were superficially Egyptian- ized and did not interfere with Egyptian culture. Their chief deity was Seth, whom they identified with an Asiatic storm god. The Hyksos intro¬ duced the horse and chariot, the compound bow, improved battle-axes, and advanced fortification techniques. Hyksos pharaohs tried to halt the spread of a Theban revolt, but their dynasty fell to Ahmose in 1521 bc.

hylomorphism \ l hl-b- , m6r- l fiz-9m\ Metaphysical view according to which every natural body consists of two intrinsic principles, one poten¬ tial (namely, primary matter) and one actual (namely, substantial form). It was the central doctrine of Aristotle’s philosophy of nature. He based his argument for hylomorphism chiefly on the analysis of change. If a being changes (e.g., from being cold to being hot), something permanent must exist that remains throughout the change; in addition, there must be an actual principle that differentiates the earlier from the later state. The permanent principle is matter, the actual principle form.

hylozoism \ l hI-b- , zo- l iz-3m\ View that all matter is alive, either in itself or by participation in the operation of a world soul or some similar prin¬ ciple. Hylozoism is logically distinct both from early forms of animism, which personify nature, and from panpsychism, which attributes some form of consciousness or sensation to all matter. The word was coined in the 17th century by Ralph Cudworth, who with Henry More (1614-1687) spoke of “plastic nature,” an unconscious, incorporeal substance that con¬ trols and organizes matter and thus produces natural events as a divine instrument of change.

Hymen Greek god of marriage. He was usually thought to be a son of Apollo by one of the Muses, perhaps Calliope. Other accounts called him the son of Dionysus and Aphrodite. In Attic legend he was a beautiful youth who rescued a group of young women, including his beloved, from a gang of pirates. He obtained the girl in marriage, and their happy life was invoked in many wedding songs.

hymn Song used in Christian worship, usually sung by the congrega¬ tion and written in stanzas with rhyme and metre. The term comes from the Greek hymnos (“song of praise”), but songs in honour of God or the gods exist in all civilizations. Christian hymnody grew out of the singing of psalms in the Temple of Jerusalem. The earliest known Christian hymn dates from c. ad 200. Hymns were prominent in the Byzantine liturgy from early times, and in the Western church they were sung by congre¬ gations until the Middle Ages, when choirs took over hymn singing. Con¬ gregational singing was reestablished during the Reformation. Martin Luther and his followers were great hymn writers, while the Calvinists preferred setting psalms to music. The compositions of Isaac Watts and John Wesley were notable in English hymnody. The Counter-Reformation led to the composition of many Roman Catholic hymns, and the Roman Catholic church restored congregational singing of hymns after the Sec¬ ond Vatican Council in the 1960s.

Hyndman Vhlnd-msnV Henry M(ayers) (b. March 7, 1842, Lon¬ don, Eng.—d. Nov. 22, 1921, London) British Marxist political leader. Educated at the University of Cambridge, he worked as a journalist before founding the socialist Democratic Federation, and in England for All (1881), the first English socialist book in almost 50 years, he expounded the ideas of Karl Marx. He steered many British socialists toward Marx¬ ism, but Friedrich Engels, who disliked Hyndman, encouraged many to break away and form the Socialist League. During World War I Hyndman took a patriotic and pro-French line, causing his ouster from the Socialist Party, whereupon he formed the National Socialist Party (1916), later renamed the Social Democratic Federation.

hyperactivity See attention deficit disorder

hyperbaric chamber \,hl-p9r-'bar-ik\ 0 / decompression cham¬ ber or recompression chamber Sealed chamber supplying a high- pressure atmosphere. Breathing air at high pressure increases the oxygen level in tissues. This is used to inhibit growth of anaerobic bacteria (as in tetanus or gas gangrene); to increase the chance that babies with certain heart malformations will survive heart surgery; or to cause air bubbles (as in air embolism or decompression sickness) to be redissolved, carried to the lungs, and exhaled as pressure is gradually returned to normal.

hyperbola \hl-'p9r-b3-la\ Curve with two separate branches, one of the conic sections. In Euclidean geometry, the intersection of a double right cir¬ cular cone and a plane at an angle that is less than the cone’s generating angle (the angle its sides make with its central axis) forms the hyperbo¬ la’s two branches (one on each nappe, or single cone). In analytic geom¬ etry, the standard equation of a hyperbola is x 2 /^ 2 - y 2 / b 2 = 1. Hyperbolas have many important physical attributes that make them useful in the design of LENSes and antennas.

hyperbolic \,hl-p3r-'ba-lik\ function In mathematics, one of a set of functions related to the hyperbola in the same way the trigonometric func¬ tions relate to the circle. They are the hyperbolic sine, cosine, tangent, secant, cotangent, and cosecant (written “sinh,” “cosh,” etc.). The hyper¬ bolic equivalent of the fundamental trigonometric identity is cosh 2 z - sinh 2 z = 1. The hyperbolic sine and cosine, particularly useful for finding special types of integrals, can be defined in terms of exponential functions: sinhx = (e — e ~ x ) 4- 2 and coshx = (e + e ~ x ) -4 2

hyperbolic geometry Non-Euclidean geometry, useful in modeling interstellar space, that rejects the parallel postulate, proposing instead that at least two lines through any point not on a given line are parallel to that line. Though many of its theorems are identical to those of Euclidean geometry, others differ. For example, two parallel lines converge in one direction and diverge in the other, and the angles of a triangle add up to less than 180°.

hypernephroma See renal carcinoma

hypertension or high blood pressure Condition in which blood pressure is abnormally high. Over time, it damages the kidneys, brain, eyes, and heart. Hypertension accelerates atherosclerosis, increasing the risk of heart attack, stroke, and kidney failure. More common in the elderly and blacks, it usually has no symptoms but can be detected by a routine blood- pressure test. Secondary hypertension, caused by another disorder (most often kidney disease or hormone imbalance), accounts for 10% of cases. The other 90% have no specific cause (essential hypertension). A low-salt diet, weight loss, smoking cessation, limited alcohol intake, and exercise can prevent or treat hypertension or reduce medication if drug therapy proves necessary. Malignant hypertension, a severe, rapidly progressing form, requires emergency treatment with drugs to dilate the blood vessels.

hypertext or hyperlink Linking of related information by electronic connections in order to allow a user easy access between them. Concep¬ tualized by Vannevar Bush (1945) and invented by Douglas Engelbart in the 1960s, hypertext is a feature of some computer programs that allows the user to select a word and receive additional information, such as a definition or related material. In Internet browsers, hypertext links (hot- links) are usually denoted by highlighting a word or phrase with a dif¬ ferent font or colour. Hypertext links create a branching or network structure that permits direct, unmediated jumps to related information. Hypertext has been used most successfully as an essential feature of the World Wide Web (see HTML; HTTP). Hyperlinks may also involve objects other than text (e.g., selecting a small picture may provide a link to a larger version of the same picture).

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HyperText Markup Language ► hysterectomy I 919

HyperText Markup Language See HTML HyperText Transfer Protocol See HTTP

hypnosis State that resembles sleep but is induced by a person (the hyp¬ notist) whose suggestions are readily accepted by the subject. The hyp¬ notized individual seems to respond in an uncritical, automatic fashion, ignoring aspects of the environment (e.g., sights, sounds) not pointed out by the hypnotist. Even the subject’s memory and awareness of self may be altered by suggestion, and the effects of the suggestions may be extended (posthypnotically) into the subject’s subsequent waking activ¬ ity. The history of hypnotism is as old as that of sorcery and magic. It was popularized in the 18th century by Franz Anton Mesmer (as “mesmerism”) and was studied in the 19th century by the Scottish surgeon James Braid (1795-1860). Sigmund Freud relied on it in exploring the unconscious, and it eventually came to be recognized in medicine and psychology as useful in helping to calm or anesthetize patients, modify unwanted behaviours, and uncover repressed memories. There remains no generally acceptable explanation for hypnosis, though one prominent theory focuses on the possibility of discrete dissociative states affecting portions of conscious¬ ness.

hypochondriasis N.hl-ps-kon-'dri-o-sosV Mental disorder in which an individual is excessively preoccupied with his own health and inclined to treat insignificant physical signs or symptoms as evidence of a serious disease. The hypochondriac may become convinced that he is ill even though he has no symptoms at all, or may exaggerate the importance of minor aches and pains, becoming obsessed with the fear of a life- threatening illness. A doctor’s reassurances often have only a slight or temporary effect on the hypochondriac’s anxieties. Hypochondriasis usu¬ ally first manifests itself in early adulthood and is equally common among males and females. In some cases it may represent a psychological cop¬ ing mechanism that the individual resorts to in order to deal with stress¬ ful life situations.

hypoglycemia X.hl-pd-gll-'se-me-oX Below-normal levels of blood glucose, quickly reversed by administration of oral or intravenous glu¬ cose. Even brief episodes can produce severe brain dysfunction. Fasting hypoglycemia can be life-threatening; it occurs most often in patients with diabetes mellitus who mistime insulin therapy or miss meals. It also results from insulin-producing tumours, starvation, or metabolic disorders. Reac¬ tive hypoglycemia occurs when the body produces too much insulin in response to sugar intake. Symptoms range from irritability to confusion and seizures, leading to coma and death in severe cases.

hypophosphatemia V.hl-po-.fas-fa-'te-me-oX Low phosphate levels in blood. It usually occurs in conjunction with other metabolic disturbances, disrupting energy metabolism and impairing delivery of oxygen to tis¬ sues. Acute hypophosphatemia causes neurological symptoms (weakness, tremors, and confusion). Chronic hypophosphatemia, from long-term deficiency, causes general weakness and appetite loss. Treatment involves correcting the metabolic problem and giving phosphate supplements. Familial hypophosphatemia, an inherited disorder, is a major cause of rickets in developed nations. See also ATP.

hyposensitization See desensitization

hypostyle Vhl-po-.stlL hall Imposing interior space with a flat roof that rests on many rows of columns. The design allows for the construc¬ tion of large spaces without arches. It was used extensively in ancient Egypt (e.g.. Temple of Amon at Karnak) and Persia. The elaborately carved pillars consumed much of the floor space and therefore assumed great importance. Hypostyles are rarely seen in more recent architecture because of more effective means of roof support.

hypotension or low blood pressure Condition in which blood pressure is abnormally low. It may result from reduced blood volume (e.g., from heavy bleeding or plasma loss after severe burns) or increased blood¬ vessel capacity (e.g., in syncope). Orthostatic hypotension—drop in blood pressure on standing—results from failure of the reflexes that contract muscles and constrict blood vessels in the legs to offset gravity as one rises. Hypotension is also a factor in poliomyelitis, shock, and barbiturate poisoning.

hypothalamus V.hl-po-'tha-lo-mosX Region of the brain containing a control centre for many autonomic-nervous-system functions. Its complex interaction with the pituitary gland makes it an important part of the endo¬ crine system. As a critical link between the body’s two control systems, the

hypothalamus regulates homeostasis. Nervous and hormonal pathways connect it with the pituitary, which it stimulates to release various hor¬ mones. The hypothalamus influences food intake, weight regulation, fluid intake and balance, thirst, body heat, and the sleep cycle. Disorders can produce pituitary dysfunction, diabetes insipidus, insomnia, and temperature fluctuations.

hypothermia Abnormally low body temperature, with slowing of physiological activity. It is artificially induced (usually with ice baths) for certain surgical procedures and cancer treatments. Accidental hypother¬ mia can result from falling into cold water or overexposure in cold weather. Underlying conditions such as cerebrovascular disease or intoxi¬ cation increase the risk from exposure. Hypothermia is serious when body temperature is below 95 °F (35 °C) and an emergency below 90 °F (32.2 °C), at which point shivering stops. Pulse, respiration, and blood pressure are depressed. Even when the victim appears dead, revival may be pos¬ sible with very gradual passive rewarming (e.g., with blankets). See also FROSTBITE.

hypothesis testing In statistics, a method for testing how accurately a mathematical model based on one set of data predicts the nature of other data sets generated by the same process. Hypothesis testing grew out of quality control, in which whole batches of manufactured items are accepted or rejected based on testing relatively small samples. An initial hypothesis (null hypothesis) might predict, for example, that the widths of a precision part manufactured in batches will conform to a normal dis¬ tribution with a given mean (see mean, median, and mode). Samples from new batches either confirm or disprove this hypothesis, which is refined based on these results.

hypoxia \,hip-'ak-se-3, hI-'pak-se-9\ Condition in which tissues are starved of oxygen. The extreme is anoxia (absence of oxygen). There are four types: hypoxemic, from low blood oxygen content (e.g., in altitude sickness); anemic, from low blood oxygen-carrying capacity (e.g., in car¬ bon monoxide poisoning); distributive, from low blood flow (e.g., gen¬ erally in shock or locally in atherosclerosis); and histotoxic, from poisoning (e.g., with cyanide) that keeps cells from using oxygen. If not reversed quickly, hypoxia can lead to necrosis (tissue death), as in heart

ATTACK.

hyrax \'hl-,raks\ Any member of three genera of small, hoofed, quad¬ ruped, rodentlike mammals (order Hyracoidea) native to Africa and extreme South Asia. Hyraxes have a squat body, a short neck and tail, and short, slender legs. Adults are 12-20 in. (30-50 cm) long and weigh 8-11 lbs (4-5 kg). They are primarily her¬ bivores. They are agile and climb well with the aid of special pads on their feet. Their relationship to ungu¬ lates is unclear. See also cony.

hyssop Vhi-S9p\ Small perennial garden herb {Hyssopus officinalis ) of the mint family, native to the area from southern Europe east to Central Asia and naturalized in North America. Its flowers and evergreen leaves have long been used as a fla¬ vouring for foods and beverages and as a folk medicine for nose, throat, and lung afflictions. The plant has a sweet scent and a warm, bitter taste.

It is used to flavour both sweet and savory foods, and such liqueurs as absinthe. Hyssop honey is consid¬ ered especially fine.

hysterectomy X.his-to-'rek-to- me\ Surgical removal of the uterus, either completely (total hysterec¬ tomy) or leaving the cervix (subtotal hysterectomy). It is performed in the presence of cancer or a benign fibroid tumour if the fibroid is large or rapidly growing, causes excessive bleed¬ ing or discomfort, or seems to be breaking down. Hysterectomy may also

Rock hyrax (Procavia capensis).

LEONARD LEE RUE III

Hyssop (Hyssopus officinalis)

WALTER DAWN

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920 I hysteresis ► Hywel Dda

be performed after cesarean section in cases of complications such as uncontrolled bleeding, gross infection, or pelvic cancer.

hysteresis X.his-to-'re-sosV Lagging of the magnetization of ferromag¬ netic material (see ferromagnetism), such as iron, behind variations of the magnetizing field. When such a material is placed in a coil of wire car¬ rying an electric current, the magnetic field so created forces atoms in the material to align with the field. This increases the total magnetic field to a maximum when all the atoms are aligned, though the total field lags behind the magnetizing field. When the intensity of the magnetizing field is decreased to zero, some field remains in the material, and if the mag¬

netizing field is reversed the total magnetization also reverses but again lags behind. The complete cycle, known as a hysteresis loop, dissipates energy in the form of heat as the magnetization is reversed.

Hywel Dda or Howel Dda Vho-wel-'thaV or Hywel the Good (d.

950) Welsh chieftain called “king of all Wales.” He inherited Seisyllwg and secured Dyfed by marriage, thereby creating the kingdom of Deheubarth. Eventually Gwynedd and Powys also came under his rule. By 942 his realm was larger than that of any earlier Welsh ruler. He codi¬ fied Welsh law during his peaceful reign and accepted the status of sub¬ king to the Anglo-Saxon king of Wessex.

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I Am movement ► ibis I 921

I Am movement U.S. religious movement founded in the 1930s by Guy Ballard (1878-1939) and his wife, Edna (1886-1971). They taught that the Mighty I Am is the source of power in everything, a power available to individuals through a number of Ascended Masters, including Jesus. Another important Ascended Master, St. Germain, spoke to Guy Ballard at Mount Shasta in northern California and revealed Ballard’s many previous lives. The movement suffered a setback when Guy died in 1939 and another when Edna and her son were indicted for fraud in 1940; though the indict¬ ment was set aside in 1946, the movement had by then lost its vitality.

l-ch'ang See Yichang

I Ching See Yijing l-pin See Yibin

lacocca U-o-'ko-koV Lee orig. Lido Anthony lacocca

(b. Oct. 15, 1924, Allentown, Pa., U.S.) U.S. automobile executive.

He was hired as an engineer by Ford Motor Co. but soon moved to its sales department and was noted for his successful promotion of the sporty yet inexpensive Mustang. He rose rapidly, becoming president of Ford in 1970. His brash manner led to his dismissal by Henry Ford

II in 1978. A year later he was hired by the nearly bankrupt Chrysler Corp. He persuaded Congress to lend Chrysler $1.5 billion in 1980 and carried out layoffs, wage cuts, and plant closings to make the company more efficient. He also shifted the company’s emphasis to more fuel-efficient cars and embarked on an aggressive advertising campaign. Within a few years Chrysler was showing record profits, and lacocca was a national celebrity with a best-selling autobiogra¬ phy, lacocca (1984). He retired in 1992.

lao Ve-'au\ Valley or Wailuku \wl-'lti-ku\ Valley Can¬ yon, eastern slope of Mount Puu Kukui, northwestern Maui,

Hawaii, U.S. Formed by erosion, it is 5 mi (8 km) long and 4,000 ft (1,200 m) deep. Iao Needle, a volcanic monolith 2,250 ft (686 m) high, soars nearly straight up from the valley floor.

Iasi \'yash\ German Jassy \'ya-se\ City (pop., 2002: 321,580), north¬ eastern Romania. Located west of the border with Moldova and northeast of Bucharest, it is on the Bahlui River. It was settled as early as the 7th century, and in the 15th century it became a customs post on the trade routes along the Prut River valley. From 1565 to 1862 Ia§i was the capi¬ tal of Moldavia. It was burned by Tatars in 1513, by Turks in 1538, and by Russians in 1686. It is the site of a university, the 16th-century church of St. Nicholas, and a national theatre.

Ibadan \i-'ba-d 3 n, ,e-ba-'dan\ City (pop., 2002 est.: 3,080,000), south¬ western Nigeria. Situated northeast of Lagos, it is the nation’s second largest city. First settled by the Egba, the modern city probably grew from a camp set up by Yoruba armies from Ife, Ijebu, and Oyo; it was taken by the British in 1893. An important commercial centre, it contains six parks, the most important of which is Agodi Garden. It is the seat of the University of Ibadan (1948) as well as a polytechnic and other special¬ ized institutions. Two major stadiums and television studios are also located there.

Ibague \,e-ba-'ga\ City (pop., 1999 est.: 393,664), central Colombia. It is located on the eastern slopes of the Cordillera Central of the Andes Mountains. Founded in 1550 on the site of an Indian village, it was moved to its present location for protection from Indian attacks. It was the nation’s capital briefly in 1854. Its location on a road linking the cities of Armenia and Bogota has made it a busy commercial centre. It is the seat of Tolima University.

Ibanez \e-'ban-yas\ (del Campo), Carlos (b. Nov. 3, 1877, Chilian, Chile—d. April 28, 1960, Santiago) Chilean soldier and president (1927- 31, 1952-58). After a 30-year military career, he helped overthrow Pres. Arturo Alessandri Palma in 1924 and effectively controlled Chile until 1931. Backed by the army, he exiled or jailed all opponents, but he failed in his attempt to rescue the ailing nitrate industry despite the help of U.S. capital. As the economy crumbled, discontent with Ibanez’s authoritari¬ anism became overt, and he fled the country. After twice attempting to regain power with the help of Chilean fascists, he won the 1952 presi¬ dential election by appealing to depressed workers and proved to be a more democratic leader than expected. See also Juan Peron.

Ibara Saikaku See Ihara Saikaku Ibarra, Jose Velasco See Jose Velasco Ibarra

Ibarruri \e-'ba-ru-re\ (Gomez), (Isidora) Dolores known as La Pasionaria (Spanish: "The Passionflower") (b. Dec. 9, 1895, Gallarta, near Bilbao, Spain—d. Nov. 12, 1989, Madrid) Spanish com¬ munist leader. The daughter of a poor miner, she became radicalized in her youth. In 1918 she published an article using her pseudonym (“The Passionflower”), and in 1920 she joined the new Communist Party of Spain. After a turbulent career, she emerged as a deputy in the Republi¬ can parliament. By the outbreak of the Spanish Civil War in 1936 she had won fame as a fiery and even violent street orator, and she coined the Republican battle cry, “No pasaran!” (“They shall not pass!”). With Fran¬ cisco Franco’s victory in 1939 she fled to the Soviet Union; she returned in 1977 after his death and the party’s relegalization. Reelected to parlia¬ ment, she resigned because of ill health, but she remained honourary president of the party until her death.

Iberian Any member of a prehistoric people of southern and east¬ ern Spain. They were largely untouched by the migrations of Celtic peoples to northern and central Spain beginning in the 8th century bc. Culturally they were influenced by Greek and Phoenician trad¬ ing colonies. On the eastern coast, tribes seem to have formed inde¬ pendent city-states; in the south, they formed monarchies. Their economy was based on agriculture, mining, and metallurgy. Their non-Indo-European language continued into Roman times.

Iberian Peninsula or Iberia Peninsula, southwestern Europe, occupied by Spain and Portugal. Its name derives from its ancient inhabitants whom the Greeks called Iberians, probably after the Ebro (Iberus) River, the peninsula’s second longest river. The Pyrenees form a land barrier in the northeast from the rest of Europe, and in the south at Gibraltar the peninsula is separated from North Africa by a narrow strait. Its western and northern coasts are bordered by the Atlantic Ocean, and its eastern coast by the Mediterranean Sea. It includes Cape da Roca, in Portugal, the most west¬ erly point of continental Europe.

Iberville \e-ber-'vel\, Pierre Le Moyne d' (baptized July 20, 1661, Ville-Marie de Montreal—d. July 9,1706, Havana, Cuba, Spanish empire) French Canadian naval hero and explorer. As a young man he led raids on English fur-trading posts on Hudson Bay. He commanded expeditions against British settlements that by 1697 had expanded the area controlled by New France. He then ventured south to fortify the Mississippi River delta and secure the claim made on Louisiana by La Salle. The settlement Iberville founded on Biloxi Bay (1699) and the forts he built below present-day New Orleans (1700) and on the Mobile River (1702) led to the later colonization of Louisiana.

ibex \1-,beks\ Any of several spe¬ cies of surefooted, sturdy wild goats found in the mountains of Europe,

Asia, and North Africa. Ibex are typi¬ cally about 3 ft (90 cm) tall at the shoulder and have brownish gray fur that is darker on the underparts. The male has a beard and large, semicir¬ cular horns.

Ibibio \,ib-9-'be-o\ People of south¬ eastern Nigeria. Their language, Ibi¬ bio, is a Benue-Congo language of the Niger-Congo family. The Ibibio, numbering about three million, are mainly rainforest cultivators. Lin¬ eage heads serve as guardians of ancestral shrines. The secret society is a prominent feature of Ibibio culture.

The Ibibio are noted for their wood sculptures of ancestor figures ( ekpu ).

ibis \'I-b3s\ Any of about 20 species of medium-sized wading birds (sub¬ family Threskiomithinae) of the same family as the spoonbills. Ibises are found in all warm regions except on South Pacific islands. They wade

il

Carved figure from a male dancer's headdress, Ibibio people, Nigeria, in the Metropolitan Museum of Art, New York City

COURTESY OF THE METROPOLITAN MUSEUM OF ART, NEW YORK CITY, THE MICHAEL C. ROCKEFELLER MEMORIAL COLLECTION, GIFT OF THE MATTHEW J. MELLON FOUNDATION, 1960 (1978. 412.403A-C)

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922 I Ibiza ► Ibn Sa'ud

in shallow lagoons, lakes, bays, and marshes, using their slender, down- curved bill to feed on small fishes and soft mollusks. Species range from 22 to 30 in. (55-75 cm) long. Ibises fly with neck and legs extended, alternately flapping and sailing. They usually breed in vast colonies.

Ibiza \e-‘be-za\ Third largest island (pop., 1999 est.: 86,953) of the Bale¬ aric Islands (Baleares), Spain. Situated in the western Mediterranean, southwest of Majorca, it has an area of 221 sq mi (572 sq km); its capi¬ tal is the town of Ibiza (pop., 2001: 34,826). A flourishing settlement in ancient times, it was inhabited by the Phoenicians and Carthaginians and has notable archaeological sites. Its landscape is hilly, and its rugged northern coast has cliffs exceeding 800 ft (245 m) in height. Its beaches and mild winter climate make it a popular tourist centre.

IblTs \i-‘bles\ In Islam, the personal name of the Devil. Iblls, one of God’s angels, refused to venerate Adam at creation. He and his followers were thrown down from heaven and await punishment at the Last Judgment. Until then he is allowed to tempt everyone but true believers to do evil. Referred to as Shaytan (Satan) in this context, it was he who purportedly tempted Adam and Eve in the Garden of Eden and caused the Fall. Iblls has long been a figure of speculation among Muslim scholars because of his ambiguous identification in the Qur’an as either an angel or a jinni.

IBM Corp. in full International Business Machines Corpora¬ tion Leading U.S. computer manufacturer, headquartered in Armonk, N.Y. It was incorporated in 1911 as the Computing-Tabulating-Recording Co., a consolidation of three office-products companies. It adopted its present name in 1924 under the leadership of Thomas J. Watson, Sr., who built it into the major U.S. manufacturer of punch card tabulators. IBM bought an electric typewriter company in 1933 and soon secured a large share of that market. In the early 1950s it entered the computer industry, investing heavily in development, and in the 1960s it produced 70% of the world’s computers. Its initial specialty was mainframe computers, but in 1981 it produced its first personal computer, the IBM PC. IBM quickly became a leader in this field, but fierce competition undermined its market share and forced the company to retrench in the 1990s. In 1995 IBM bought the software manufacturer Lotus Development Corp.

Ibn al-'Arab? \,ib-nul-ar-a-'be\ (b. July 28, 1165, Murcia, Valencia—d. Nov. 16, 1240, Damascus) Islamic mystic and theologian. Born in Spain, he traveled widely in Spain and North Africa in search of masters of Sufism. In 1198 he began a pilgrimage to the Middle East, visiting Mecca, Egypt, and Anatolia before settling in Damascus in 1223. Famous and honoured as a spiritual master, he spent the rest of his life in contempla¬ tion, teaching, and writing. His great work was The Meccan Revelations, a personal encyclopedia covering all the esoteric sciences in Islam and his own inner life. He also wrote one of the most important works in Islamic mystical philosophy, The Bezels of Wisdom (1229).

Ibn ‘Aqll \,i-b9n-a-'kel\ (b. 1040, Baghad—d. 1119) Islamic theologian. Trained in the tenets of the Hanball school (see Ahmad ibn hanbal), the most traditional school of Islamic law, he outraged his teachers by striv¬ ing to incorporate liberal theological ideas into the tradition. He sought to use reason and logical inquiry to interpret religion, and he was influ¬ enced by the teachings of al-HALLAJ. In 1066 he was appointed professor at the mosque of al-Mansur in Baghdad, but persecution by conservative theologians soon led to his retirement, and in 1072 he was forced to retract his beliefs publicly.

Ibn Battutah \,ib-3n-ba-'tu-ta\ orig. Abu 'Abd Allah Muhammad ibn ‘Abd Allah al-Lawati al-Tanjl ibn Battutah

(b. Feb. 24, 1304, Tangier, Mor.—d. 1368/69, Morocco) Noted Arab trav¬ eler and writer. He received a traditional juristic and literary education in Tangier. After a pilgrimage to Mecca (1325), he decided to visit as many parts of the world as possible, vowing “never to travel any road a second time.” His 27-year wanderings through Africa, Asia, and Europe covered some 75,000 mi (120,000 km). On his return, he dictated his reminis¬ cences, which became one of the world’s most famous travel books, the Rihlah.

Ibn Gabirol V.i-bon-ga-'be-roL orig. Solomon ben Yehuda ibn Gabirol Latin Avicebron (b. c. 1022, Malaga, Caliphate of Cordoba—d. c. 1058, Valencia, Kingdom of Valencia) Jewish poet and philosopher. Educated in both the Hebrew and Arabic literary heritages, he became famous at age 16 for his religious hymns in Hebrew and was later a court poet of the vizier of Granada. The more than 200 secular and 200 religious poems that survive make him an outstanding figure of the

Hebrew school of poetry that flourished in Moorish Spain. Other works include influential writings of Neoplatonic philosophy and a collection of proverbs in Arabic.

Ibn Hazm \ I i-b3n- , ka-z9m\ in full AbG Muhammad c Ali ibn Ahmad ibn Sa'Id ibn Hazm (b. Nov. 7, 994, Cordoba, Caliphate of Cordoba—d. Aug. 15, 1064, Manta Lisham, near Sevilla) Islamic scholar and theologian. Born in Spain, he lived through the civil war that ended the Spanish Umayyad caliphate and was afterward imprisoned for hav¬ ing supported it. As a leader of the Zahirl school of jurisprudence, he taught that legal theory must rely on a literal interpretation of the Qur’an and tradition. His beliefs were often attacked, and his books were burned in public. His scholarship included not only jurisprudence and theology but also logic, literature, and history. Famed for his mastery of Arabic, he wrote about 400 books, fewer than 40 of which survive.

Ibn Ishaq \,i-b3n-es-'hak\ in full Muhammad ibn Ishaq ibn Yasar ibn Khiyar (b. c. 704, Medina, Arabia—d. 767, Baghdad) Arab biographer of Muhammad. His father and two uncles collected and trans¬ mitted information about Muhammad in Medina, and Ibn Ishaq soon became an authority on the Prophet’s military campaigns (maghazt). He studied in Alexandria and subsequently moved to Iraq, where he met many people who provided him with information for his biography, which became the most popular biography of Muhammad in the Muslim world but which survives only in the recension by Ibn Hisham.

Ibn Janah \,ib-3n-ja-'nak\ or Rabbi Jonah (b. c. 990, Cordoba—d. c. 1050, Zaragoza, Spain) Spanish scholar famed as a Hebrew grammar¬ ian and lexicographer. A practicing physician and a devout Jew, he founded the study of Hebrew syntax, establishing the rules of biblical exegesis and clarifying many difficult passages. His principal work was the two-volume Book of Exact Investigation, a Hebrew grammar and lexicon. All his writings were in Arabic, and he made extensive compari¬ sons of Hebrew and Arabic words.

Ibn Khaldun V.ib-on-kal-'dunX orig. Abu Zayd ‘Abd al-Rahman ibn Khaldun (b. May 27, 1332, Tunis, Tun.—d. March 17, 1406, Cairo, Egypt) Noted Arab historian. He was employed in court posts by various rulers in Tunis, Fes, and Granada. After retiring from politics in 1375, he wrote his masterpiece, the Muqaddimah (“Introduction”), in which he examined the nature of society and social change and developed one of the earliest rational philosophies of history. He also wrote a definitive his¬ tory of Muslim North Africa, Kitab al-lbar. In 1382 he went to Cairo, where he was appointed professor of law and religious judge. In 1400 he was trapped in Damascus during that city’s siege by Timur, spending seven weeks in the Central Asian conqueror’s camp before securing his own release and that of a number of colleagues. He is regarded as the greatest premodern Arab historian.

Ibn Rushd See Averroes

Ibn Sa'ud \,ib-9n-sa-'ud\ in_full 'Abd a I- 1 Aziz ibn 'Abd al-Rahman ibn Faysal Al Sa'ud (b. c. 1880, Riyadh, Arabian Peninsula—d. Nov. 9, 1953,

Al-Ta’if, Saud.Ar.) Founder of modern-day Saudi Arabia. Though the Sa c 0d dynasty had ruled much of Arabia from 1780 to 1880, in Ibn Sa'ud’s infancy the family was forced out by its rivals, the Rashids.

At age 21 Ibn Sa'ud led a daring raid against the Rashids and recaptured the family capital, Riyadh. He was driven out two years later but recon¬ stituted his forces and fought on, using puritanical Wahhabi Islam to rally nomadic tribesmen to his cause, thereby forming the Ikhwan. In 1920-22 he defeated the Rashids and doubled his own territory. In 1924 he conquered the Hejaz (see Husayn ibn c Au). In 1932 he formally created the Kingdom of Saudi Arabia, which he ruled as an absolute monarch. He signed his first oil deal in 1933 but remained virtually penniless until the 1950s, when oil revenues began pouring in. His sons succeeded him.

Ibn Sa'ud

CAMERA PRESS

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Ibn Sind ► ice dancing I 923

Ibn Sina See Avicenna

Ibn Taymiyyah y.i-bsn-tl-'me-aV (b. 1263, Harran, Mesopotamia—d. Sept. 26, 1328, Cairo) Islamic theologian. He was educated in Damascus, where he joined the Pietist school. He sought to return Islam to a strict interpretation of its sources in the Qur’an and the sunnah, as well as to rid it of customs he considered contrary to the law, including the worship of saints. He was imprisoned repeatedly in Cairo after his outspoken criti¬ cisms offended religious authorities. He spent his last 15 years as a school¬ master in Damascus, where he gathered many disciples. He died in prison. His writings are a major source of the Wahhabiyyah, a puritanical move¬ ment founded by Muhammad ibn ‘Abd al-WAHHAB.

Ibn Tibbon U-bon-'ti-bonV Judah ben Saul (b. 1120, Granada, Spain—d. c. 1190, Marseille) Jewish physician and translator. Persecu¬ tions of the Jews forced him to flee Spain, and he settled in southern France in 1150 to practice medicine. His translations of philosophical works by Arabic-speaking Jews helped disseminate Arabic and Greek culture in medieval Europe. His son and grandson were also noted schol¬ ars and translators.

Ibn Tulun \,i-b3n-tu-'lun\ Mosque Huge, majestic red-brick mosque in Cairo. It was built (876-879) by Ahmad ibn Tulun (835-884), the Muslim governor of Egypt and Syria. The mosque’s crenellated walls have merlons (see battlement) that are shaped and perforated in a decora¬ tive pattern, and its three courts are lined with arcades of broad arches and heavy pillars. The arches are decorated with elaborately carved stucco. The main space is divided by pillars into five long aisles origi¬ nally ornamented with panels of carved wood. Classed as a historic monu¬ ment in 1890, the mosque has since been completely restored.

Ibo See Igbo

Ibrahim Pasha Mb-ra-'hem-'pash-aV (b. 1789, Kavalla, Rumelia—d. Nov. 10, 1848, Cairo, Egypt) Egyptian general. After helping train the new Egyptian army, he won military fame in Syria, defeating an Ottoman force, and Syria and Adana were ceded to Egypt, with Ibrahim as governor- general (1833). His administration was relatively enlightened; he created a consultative council and suppressed the feudal regime. Sultan Mahmud II (r. 1808-39) then sent an Ottoman army to invade Syria, and Ibrahim won his greatest victory in 1839 when the Ottoman fleet deserted to Egypt. However, the European powers, fearing the disintegration of the Ottoman Empire, forced the Egyptians to evacuate the occupied territories. Ibrahim became viceroy of Egypt in 1848 shortly before his death.

Ibsen Vip-sonA English Vib-S9n\, Henrik (Johan) (b. March 20, 1828, Skien, Nor.—d. May 23, 1906,

Kristiania) Norwegian playwright.

At age 23 he became theatre director and resident playwright of the new National Theatre at Bergen, charged with creating a “national drama.” He directed the Norwegian Theatre in Kristiana from 1857 to 1863, when the theatre went bankrupt. He then set off on extended travels in Europe, beginning a self-imposed exile that would last until 1891. In Italy he wrote the troubling moral tragedy Brand (1866) and the buoyant Peer Gynt (1867). After the satire Pillars of Society (1877) he found his voice and an international audience with powerful studies of middle-class morality in A Doll’s House (1879),

Ghosts (1881), An Enemy of the People (1882), The Wild Duck (1884), and Rosmersholm (1886).

His more symbolic plays, most of them written after his return to Norway in 1891, include Hedda Gabler (1890), The Master Builder (1892), Little Eyolf (1894), and When We Dead Awaken (1899). Emphasizing character over plot, Ibsen addressed social problems such as political corruption and the changing role of women as well as psychological conflicts stemming from frustrated love and destructive family relationships. He greatly influenced European the¬ atre and is regarded as the founder of modern prose drama.

ibuprofen \ I I-byu-'pro-f3n\ Analgesic, one of the NSAIDs, especially effective against minor pain, fever, and inflammation. It works by inhib¬ iting prostaglandin synthesis. It may irritate the gastrointestinal tract and should not be taken by anyone who has an allergy to aspirin or takes anti¬ coagulants. Brand names include Advil, Motrin, and Nuprin. See also ACETAMINOPHEN.

1C See INTEGRATED CIRCUIT Icarus See Daedalus

ICBM in full intercontinental ballistic missile Land-based, nuclear-armed ballistic missile with a range of more than 3,500 mi (5,600 km). Only the U.S., Russia, and China field land-based missiles of this range. The first ICBMs were deployed by the Soviet Union in 1958, with the U.S. following the next year and China some 20 years later. The prin¬ cipal U.S. ICBM is the silo-launched Minuteman missile. Submarine- launched ballistic missiles (SLBMs) with ranges comparable to ICBMs include the Trident missile, deployed by the U.S. and Britain, and several systems deployed by Russia, China, and France.

ice Solid form of liquid water and water vapour. Below 32 °F (0 °C), liquid water forms a hard solid and water vapour forms frost on surfaces and snowflakes (see snow) in clouds. Unlike most liquids, water expands on freezing, so ice is less dense than liquid water and therefore floats. It consists of compact aggregates of many crystals (with hexagonal sym¬ metry), although ice formed from the bulk liquid does not normally have crystal faces. Molecules in the crystal are held together by hydrogen bonds (see hydrogen bonding). With a very high dielectric constant, ice conducts electricity much better than most nonmetallic crystals. At very high pres¬ sures, at least five other crystal forms of ice occur.

ice age or glacial age Any geologic period during which thick ice sheets cover vast areas of land. Such periods of large-scale glaciation may last several million years and drastically reshape surface features of entire continents. A number of major ice ages have occurred throughout the Earth’s history; the most recent periods were during the Pleistocene Epoch (1.8 million-10,000 years ago).

ice cream Frozen dairy food. Ice cream is made from cream or butter- fat, milk, sugar, and flavourings. Fruit ices (nondairy frozen desserts) were introduced into Europe from the East sometime after being first described by Marco Polo in his journals. Creation of the first true cream ice is cred¬ ited to a Parisian cafe owner named Tortoni in the late 18th century. The ice-cream cone originated at the 1904 World’s Fair in St. Louis, Mo., U.S. Commercial ice cream is made by heating and blending its ingredients to form a mix, which is then pasteurized and homogenized. The mix is rip¬ ened for several hours and then agitated while being frozen to incorpo¬ rate air; the highest-quality ice creams incorporate the least air. Ice cream is now available in hundreds, if not thousands, of flavours.

ice dancing Sport in which ice-skating pairs perform to music routines similar to ballroom dances. Ice dancers are judged on the difficulty and originality of their dance steps, their interpretation of the music, and their

French ice dancers Isabelle and Paul Duchesnay competing at the World Ice-Dance Championships.

© DUOMO PHOTOGRAPHY

© 2006 Encyclopaedia Britannica, Inc.

924 I ice formation ► Icelandic language

© MERRIAM-WEBSTER INC.

timing and unison. Unlike figure skating, ice dancing does not allow movements of strength or technical skill (particularly overhead lifts, jumps, and spins of more than one- and-a-half rotations). It has been an Olympic event since 1976.

ice formation Any mass of ice that occurs on the Earth’s continents or surface waters. Such masses form wherever substantial amounts of liq¬ uid water freeze and remain in the solid state for some period of time.

Examples include glaciers, icebergs, sea ice, and ground ice associated With PERMAFROST.

ice hockey Game played on an ice rink by two teams of six players on skates. The object is to drive a puck (a small, hard rubber disk) into the opponents’ goal with a hockey stick, thus scoring one point. A game con¬ sists of three 20-minute periods. The first true ice-hockey game was played in 1875 between two student teams at Montreal’s McGill Univer¬ sity. The National Hockey League, consisting of U.S. and Canadian pro- fessional teams, was organized in

Hockey was introduced at the Olympic Games in 1920. It is a very aggressive game, and the puck is often taken from a player by means of a hit to the body, called a check. Some contact, such as checking from behind and slashing with the stick, is illegal and draws a penalty. See also Stanley Cup.

iceberg Floating mass of ice that has broken from the seaward end of a glacier or a polar ice sheet. Icebergs are typically found in open seas, especially around Greenland and Antarctica. They form mostly during each hemisphere’s spring and summer, when warmer weather increases the rate of calving (separation) of icebergs at the boundaries of the Green¬ land and Antarctic ice sheets and smaller outlying glaciers. In the North¬ ern Hemisphere, about 10,000 icebergs are produced each year from the Greenland glaciers, and an average of 375 flow into the North Atlantic shipping lanes, where they are a hazard to navigation, especially because only about 10% of an iceberg is exposed above the surface of the sea.

Iceland officially Republic of Iceland Island country, northern Atlantic Ocean, between Norway and Greenland. Area: 39,741 sq mi (102,928 sq km). Population (2005 est.): 295,000. Capital: Reykjavik. The people are overwhelmingly Nordic. Language: Icelandic (official). Reli¬ gion: Christianity (Evangelical Lutheran [official]). Currency: krona. One of the most active volcanic regions in the world, Iceland contains about 200 volcanoes and accounts for one-third of Earth’s total lava flow. One- tenth of the area is covered by cooled lava beds and glaciers, including Vatnajokull. Iceland’s rugged coastline is more than 3,000 mi (4,800 km) long. The economy is based heavily on fishing and fish products but also includes hydropower production, livestock, and aluminum processing. Iceland is a republic with one legislative house; its chief of state is the president, and the head of government is the prime minister. Iceland was settled by Norwegian seafarers in the 9th century and was Christianized by 1000. Its legislature, the Althingi, founded in 930, is one of the oldest legislative assemblies in the world. Iceland united with Norway in 1262 and with Denmark in 1380. It became an independent state of Denmark in 1918, but it severed those ties to become an independent republic in 1944. Vigdis Finnbogadottir, the first woman in the world to be elected a head of state, served four terms as the republic’s president (1980-96). See map opposite.

Icelanders' sagas or family sagas Class of heroic prose narra¬ tives written in the 13th century about the great families who lived in Iceland from 930 to 1030. They represent the zenith of classical Icelan¬ dic SAGA writing and are far in advance of any contemporary medieval literature in their realism, controlled style, character delineation, and over¬ whelming tragic dignity. Their artistic unity, length, and complexity sug¬

face-off

goal goal

A typical professional North American ice-hockey rink. U.S. college rinks are usually wider (100 ft), and international rinks vary in both length and width. Blue lines mark the respective off-sides areas; the space between them is called the neutral zone. The puck is put into play by being dropped between two players at the face-off spots; all players except those facing off must stand outside the face-off circle. A major penalty requires that a player go to the penalty box for five minutes while his team plays shorthanded.

gest that they were written by individual authors rather than composed orally. Jus¬ tice, not courage, is often the primary vir¬ tue, as in the greatest of the family sagas,

Njals saga.

Icelandic language National language of Iceland, one of the Ger¬ manic languages. It developed from the Norse speech brought to Iceland by settlers from western Norway in the 9th-10th centuries. Old Icelandic (see Old Norse) is the language of the sagas and other medieval poems. In grammar, vocabulary, and spelling, modern Icelandic is the most con¬ servative of the Scandinavian languages; modern Icelanders can still read Old Norse sagas. Icelandic once borrowed words from Danish, Latin, and the Celtic and Romance languages, but a purist movement that began in the early 19th century has replaced most of these loanwords with words formed only from Icelandic elements.

© 2006 Encyclopaedia Britannica, Inc.

Iceman ► identity of indiscernibles I 925

Iceman Body of a man found sealed in a glacier in the Tirolean Otztal Alps in 1991 and dated to 3300 bc. It has revealed significant details of everyday life during the Neolithic Period. The Iceman (also called Simi- laun Man or Otzi, after the glacier and valley) is tattooed on parts of his body and has trimmed hair; it had previously been thought that tattooing and hair cutting began much later in Europe. He wore neatly stitched deerskin clothing, a woven grass cape, and leather shoes stuffed with grass for insulation. He carried two fungi on leather thongs, probably for medicinal purposes, and a birchbark box containing food supplies. His other equipment included a copper ax, a flint dagger, a yew bow, and a deerskin quiver holding expertly finished arrows. Although it was initially believed that he had died of freezing, X-ray examination in 2001 showed that an arrowhead was lodged in his left shoulder, suggesting that he had likely bled to death after being shot.

Ichikawa \,e-che-'ka-wa\ Kon (b. Nov. 20, 1915, Ise, Japan) Japanese film director. After working in the animation department of the Toho film studio, he directed his first film, The Girl at Dojo Temple (1946). He introduced sophisticated Western-style comedy to Japan in films such as The Woman Who Touched Legs (1952) and Mr. Pu (1953). He gained international acclaim for his antiwar films The Burmese Harp (1956) and Fires on the Plain (1959) and the documentary Tokyo Olympiad (1965). His other major films include Conflagration (1958), My Enemy the Sea (1963), and An Actor’s Revenge (1963).

ICI See Imperial Chemical Industries PLC

icon In Eastern Orthodoxy, the representation of sacred persons or events in murals, mosaics, or paintings on wood. After the Iconoclastic Contro¬ versy of the 8th-9th century, which disputed the religious function and meaning of icons (see iconoclasm), the Eastern churches formulated an official doctrine that approved their use, stating that since God had assumed material form in the person of Jesus, he and other sacred person¬ ages could be represented in works of art. Usually depicting Jesus or Mary but also sometimes saints, icons are relied on as objects of ven¬ eration and as tools for instruction.

iconoclasm Destruction of reli¬ gious images. In Christianity and Islam, iconoclasm was based on the Mosaic prohibition against making graven images, which were associ¬ ated with idolatry. The making of portraits of Christ and the saints was opposed in the early Christian church, but icons had become popu¬ lar in Christian worship by the end of the 6th century, and defenders of icon worship emphasized the symbolic nature of the images. Opposition to icons by the Byzantine emperor Leo III in 726 led to the Iconoclastic Controversy, which continued in the Eastern church for more than a cen¬ tury before icons were again accepted. Statues and portraits of saints and religious figures were also common in the Western church, though some Protestant sects eventually rejected them. Islam still bans all icons, and iconoclasm has played a role in the conflicts between Muslims and Hin¬ dus in India.

iconostasis Vj-ko-'nas-to-sosV In Eastern Christian churches of Byzan¬ tine tradition, a solid screen of stone, wood, or metal separating the sanc¬ tuary from the nave. It has a royal door in the center and two smaller doors on either side. Covered with panel icons, it always includes the icon of the Incarnation (mother with child) on the left and the second coming of Christ on the right; icons of the four Evangelists, the Annunciation, and the Last Supper cover the royal doors themselves.

id In Freudian psychoanalytic theory, one of the three aspects of the human personality, along with the ego and superego. The id is the source of instinctual impulses such as sex and aggression as well as primitive needs that exist at birth. It is entirely nonrational and functions accord¬ ing to the pleasure-pain principle, seeking immediate fulfillment of its impulses whenever possible. Its working processes are completely uncon¬

scious in the adult, but it supplies the energy for conscious mental life, and it plays an especially important role in modes of expression that have a nonrational element, such as the making of art. The primary methods for unmasking its content, according to Sigmund Freud, are dream analy¬ sis and free association.

Ida, Mount Name of two separate mountains, one in Anatolia and the other on the island of Crete. The Anatolian mountain is located near the site of ancient Troy and once held a Classical shrine where Paris is said to have judged the beauty of three Greek goddesses. From its highest point, about 5,800 ft (1,800 m), the gods are said to have witnessed the Trojan War. The second mountain, in west-central Crete, is the island’s highest point, reaching 8,058 ft (2,456 m). It also held a Classical shrine, which included the cave where Zeus, the father of the Greek pantheon, was said to have been reared.

Idaho State (pop., 2000: 1,293,953), northwestern U.S. It is bordered by Canada and the U.S. states of Montana, Wyoming, Utah, Nevada, Oregon, and Washington. It covers 83,574 sq mi (216,456 sq km). Its capital is Boise. Idaho is dominated by the Rocky Mountains, which extend from the Canadian border to south-central Idaho and along the Wyoming border. Its most extensive valley surrounds the Snake River, which flows through Hells Canyon, the deepest gorge in North America. First occupied by American Indians, the region was explored by the Lewis and Clark Expe¬ dition in 1805. It was part of the disputed Oregon Country that passed to the U.S. when Britain relinquished its claims by treaty in 1846. Discov¬ ery of gold in 1860 brought an influx of settlers. It became Idaho Terri¬ tory in 1863 and was admitted to the Union as the 43rd state in 1890. Labour protests during 1890-1910 involving the Industrial Workers of the World erupted frequently. During the late 20th century, Idaho developed its agriculture and industry and promoted its natural wilderness.

ideal gas See perfect gas

idealism In metaphysics, the view that stresses the central role of the ideal or the spiritual in the constitution of the world and in mankind’s interpre¬ tation of experience. Idealism may hold that the world or reality exists essentially as spirit or consciousness, that abstractions and laws are more fundamental in reality than sensory things, or, at least, that whatever exists is known to mankind in dimensions that are chiefly mental—that is, through and as ideas. Metaphysical idealism asserts the ideality of reality; epistemological idealism holds that in the knowledge process the mind can grasp only its own contents. Metaphysical idealism is thus directly opposed to materialism, and epistemological idealism is opposed to realism. Absolute idealism (see G. W. F. Hegel) includes the following principles: (1) the everyday world of things and persons is not the world as it really is but merely as it appears in terms of uncriticized categories; (2) the best reflection of the world is in terms of a self-conscious mind; (3) thought is the relation of each particular experience with the infinite whole of which it is an expression; and (4) truth consists in relationships of coherence between thoughts, rather than in a correspondence between thoughts and external realities (see coherentism). See also George Berkeley.

Idelsohn \'e-d 3 l- I zon\, Abraham (Zevi) (b. July 14, 1882, Felixberg, Latvia, Russian Empire—d. Aug. 14, 1938, Johannesburg, S.Af.) Latvian musicologist. After studies in Germany he served as a synagogue cantor there (from 1903) before moving to Johannesburg and then to Jerusalem in 1905. Later he moved to the U.S., but after a stroke in 1934 he returned to Johannesburg. His monumental comparative studies of Jewish music in many parts of the world established that the tradition had remained relatively unchanged over time and also suggested connections between Jewish chant and the origins of Gregorian chant. He composed the first Hebrew opera, Yiftah (1922), and the song “Hava nagila.”

Identity Christianity North American Christian movement that iden¬ tifies Anglo-Saxon and other European peoples with the lost tribes of Israel. Anti-Semitic and racist, Identity Christianity posits that God’s cov¬ enant was actually with the European peoples and that the Jews are the offspring of Eve and Satan, and it characterizes blacks as subhuman. Though it has been largely unsuccessful in persuading “white Israelites” of their purported identity, small churches are active (mainly in the north¬ western U.S.) and the movement proselytizes through publications, recordings, and the Internet.

identity of indiscernibles Principle enunciated by G.W. Leibniz that denies the possibility of two objects being numerically distinct while sharing all their non-relational properties in common, where a relational

"Annunciation/' reverse of a double¬ sided painted panel icon from Con¬ stantinople, early 14th century; in the Skopolije Museum, Skopje, Macedonia

HIRMER FOTOARCHIV, MUNCHEN

© 2006 Encyclopaedia Britannica, Inc.

926 I identity theory ► Ignatyev

property is one that involves bearing a relation to another object. More formally, the principle states that if x is not identical to y, then there is some non-relational property P such that P holds of x and does not hold of y, or that P holds of y and does not hold of x. Equivalently, if x and y share all their non-relational properties, then x is identical to y. Its con¬ verse, the principle of the indiscemibility of identicals (also known as Leibniz’s Law), asserts that if x is identical to y, then every non-relational property of x is a property of y, and vice versa.

identity theory In the philosophy of mind, the doctrine that mental events are identical to physico-chemical events in the brain. So-called “type” identity theory asserts that each type of mental event, such as pain, is identical to some type of event in the brain, such as the firing of c-fibres. In response to objections based on the assumed “multiple realizability” of mental states, “token” identity theory makes the weaker claim that each token of a mental event, such as a particular pain, is identical to some token of a brain event of some type. See also mind-body problem.

ideology Form of social or political philosophy in which practical ele¬ ments are as prominent as theoretical ones. The term was coined in 1796 by the French writer Antoine-Louis-Claude, Comte Destutt de Tracy (b. 1754—d. 1836), as a label for his “science of ideas.” Certain character¬ istics of his thought proved generally true of ideologies, including a more or less comprehensive theory of society, a political program, anticipation of a struggle to implement that program (thus requiring committed fol¬ lowers), and intellectual leadership. Destutt de Tracy’s ideas were adopted by the French Revolutionary government in building its version of a democratic, rational, and scientific society (see Directory). Napoleon first gave the term a negative connotation with his scorn for what he called ideologues. Ideology is often contrasted unfavourably with pragmatism. The significance of ideology follows from the fact that power is rarely exercised without some ideas or beliefs that justify support.

Iditarod \,I- , dit-3- l rad\ Trail Sled Dog Race U.S. dogsled race. It is held each March and run over a route between Anchorage and Nome, Alaska. It originated in 1967 as a race 56 mi (90 km) long, but by 1973 it had evolved into the current race, a 1,152-mi (1,855-km) trek roughly tracing an old mail route established in 1910. The race also commemo¬ rates an emergency mission to get medical supplies to Nome during a diphtheria epidemic in 1925. It typically takes 9-14 days to complete the race. See also dogsled racing.

idol Image or statue of a deity used as an object of worship. In Judaism, the making of any representation of God is strictly forbidden, as is the fash¬ ioning of any “graven image.” Islam has also adhered to this rule. In Chris¬ tianity, there has been a general acceptance of pictorial or sculpted images of Jesus and the saints and, on occasion, God, and Christianity has thus always faced the danger that such representations could be venerated superstitiously as idols. In Jainism, Hinduism, and Buddhism images of gods and saints are common; they are often the object of veneration. In Hin¬ duism, a statue may be treated as a god as an act of devotion but loses its special status when the act of devotion is finished (see Durga-puja, puja).

Idris \id-'res\ I in full SIdl Muhammad Idris al-Mahdl al-SanusT (b. March 13, 1890, Jarabub, Cyrenaica, Libya—d. May 25, 1983, Cairo, Egypt) King of Libya (1951-69). He succeeded his father in 1902 as leader of Cyrenaica but did not rule in his own name until 1916. Negotiations with Italy, which held the Libyan coast, resulted in agree¬ ments that confirmed Idris’s authority (1917) and established a parliament (1919). His refusal to disarm his tribal supporters, however, led to Italy’s invasion of Tripolitania in 1922, and Idris went into exile until after World War II (1939—45). In 1949 Cyrenaica and the other two Libyan provinces united under a constitutional monarchy headed by Idris. Independence was declared in 1951. He was overthrown by Col. Muammar al-Qaddafi in a military coup in 1969.

Idrlsid \'id-ri-sid\ dynasty Arab Muslim dynasty that ruled Berber areas of Morocco (789-921). The founder, Idris I (r. 789-791), established the shariflan tradition in Morocco, by which the claim to descent from Muhammad was established as the principle for monarchic rule. His son Idris II (r. 803-828) founded Fez (modern Fes) in 808. The dynasty was the first to incorporate both Berbers and Arabs. It broke up into rival prin¬ cipalities, paving the way for another Berber group, the Almoravid dynasty.

idyll or idyl Vl-dal, 'i-dal\ In literature, a simple descriptive work in poetry or prose that deals with rustic life or pastoral scenes or suggests a mood of peace and contentment. Idylls have taken varying forms, from

the eclogue to the long narrative poem treating an epic, romantic, or tragic theme (such as Alfred Tennyson’s “Idylls of the King”).

Ifat \i-'fat\ (1285-1415) Muslim state, central Ethiopia. Flourishing in the fertile uplands, it was established through the conquests of a 13th-century ruler known as Walashma. It served as a buffer between the kingdom of Damot and the Christian kingdom of Ethiopia. Ifat was conquered by the Ethiopian king Amda Tseyon in 1328 and made tributary to Ethiopia. After a long series of revolts, it was destroyed in 1415 when it was annexed to Ethiopia.

Ifni \'if-ne\ Region, southwestern Morocco. Located on the coast of the Atlantic Ocean, it has an area of some 580 sq mi (1500 sq km). It was settled in 1476 by Diego Garcia de Herrera, lord of the Canaries, as a Spanish fishing, slaving, and trading locality. Abandoned in 1524 because of disease and the hostility of the local population, Spain reclaimed it fol¬ lowing a treaty with Morocco in 1860. Effective Spanish reoccupation began in 1934, and it became part of Spanish West Africa in 1946. Ifni was ceded to Morocco in 1969.

IG Farben World’s largest chemical cartel from its founding in Germany until its dissolution by the Allies after World War II. It grew out of a com¬ plex merger of German manufacturers of chemicals, pharmaceuticals, and dyestuffs {Farben). Its major members were the companies known today as BASF AG, Bayer AG, Hoechst AG, Agfa-Gevaert Group, and Cassella AG. They formed a loose association in 1916 and were formally united in 1925, with headquarters in Frankfurt. IG Farben expanded internationally in the late 1920s and the 1930s. During World War II, it established a synthetic oil and rubber plant at Auschwitz to take advantage of slave labour by the death camp’s inmates, on whom it also conducted drug experiments. After the war, several company officials were convicted of war crimes, and IG Farben was broken up into three independent companies.

Igbo \'ig-bo\ or Ibo Ve-bo\ People of southeastern Nigeria. The Igbo speak dialects of Igbo, a Benue-Congo language of the Niger-Congo fam¬ ily (see Niger-Congo languages). Before European colonization the Igbo lived in autonomous local communities, but by the mid 20th century they had developed a strong sense of ethnic identity. During conflicts in 1966 many Igbo in northern Nigeria were killed or forced into their traditional homelands in the east. In 1967 the Eastern region tried to secede from Nigeria as the independent nation of Biafra; hundreds of thousands of Igbo were killed or died of starvation. Today they number some 20 million. Many are farmers, but trading, crafts, and wage labour are also important, and many have become civil servants and business entrepreneurs.

igloo Temporary dome-shaped winter home or hunting-ground dwelling of Canadian and Greenland Inuit (Eskimos), made from blocks of snow. The builder chooses a deep snowdrift of fine-grained, compact snow and cuts it into blocks. After a row of blocks has been laid in a circle, their top surfaces are shaved off in a sloping angle to form the first rung of a spiral. Additional blocks are added to the spiral to draw it inward until a dome is completed, leaving a ventilation hole at the top.

Ignarro, Louis J(oseph) (b. May 31,1941, Brooklyn, N.Y., U.S.) U.S. pharmacologist. He earned a Ph.D. from the University of Minnesota. Along with Robert F. Furchgott and Ferid Murad, Ignarro was awarded a 1998 Nobel Prize for the discovery that nitric oxide acts as a signaling mol¬ ecule in the cardiovascular system. Ignarro concluded that the factor that Furchgott had named endothelium-derived relaxing factor was nitric oxide. This work uncovered an entirely new mechanism by which blood vessels in the body relax and widen. It was the first discovery that a gas could act as a signaling molecule in a living organism. The principle behind the drug Viagra, used to treat impotence, was based upon this research.

Ignatius of Antioch \ig-'na-sh3s\, Saint (d. c. 110, Rome; Western feast day October 17; Eastern feast day December 20) Early Christian martyr. Probably of Syrian origin, he may have been a pagan who per¬ secuted Christians before his conversion. He succeeded St. Peter the Apostle as bishop of Antioch. During the reign of Trajan, Roman authori¬ ties arrested Ignatius and sent him to Rome, where he was tried and executed. He wrote a series of famous letters on the journey to Rome, attempting to encourage his fellow Christians during their persecution. The letters condemn two sets of heretics: the Judaizers, who insisted that Christians continue to follow Jewish law, and the Docetists, who main¬ tained that Jesus only appeared to suffer and die on the cross.

Ignatyev \ig-'nat-yiA, Nikolay (Pavlovich), Count (b. Jan. 29, 1832, St. Petersburg, Russia—d. July 3, 1908, Krupodernitsy estate, Kiev

© 2006 Encyclopaedia Britannica, Inc.

igneous rock ► ijtihad I 927

province) Russian politician and diplomat under Tsar Alexander II. A career diplomat, he concluded a treaty with China in 1860 that allowed Russia to construct the city of Vladivostok and become a major power in the northern Pacific. Appointed head of the foreign ministry’s Asian depart¬ ment, he gained jurisdiction over Russia’s relations with the Ottoman Empire as well, and in 1864 he became ambassador to Constantinople. An advocate of Pan-Slavism, he encouraged Serbia and Bulgaria in a revolt that proved unsuccessful. In 1878, after Russia’s victory in the Russo- Turkish War, he negotiated the favourable Treaty of San Stefano. The western European powers replaced it with the Treaty of Berlin, far less favourable to Russia, and he was forced to resign.

igneous rock Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary rocks. Though they vary widely in composition, most igneous rocks consist of quartz, feldspars, pyroxenes, amphiboles, micas, olivines, nepheline, leucite, and apatite. They may be classified as intrusive or extrusive rocks.

ignition system In a gasoline engine, the means used for producing an electric spark to ignite the fuel-air mixture in the cylinders to produce the motive force. The ignition system consists of a storage battery recharged by a generator, an induction coil, a device to produce timed high-voltage discharges from the induction coil, a distributor, and a set of spark plugs. The battery provides an electric current of low voltage, usually 12 volts, that is converted by the system to some 40,000 volts. The distributor routes the successive bursts of high-voltage current to each spark plug in the proper firing order.

iguana \i-'gwa-n3\ Any of about 13 of the larger members of the lizard family Iguanidae. Best known is the common iguana {Iguana iguana ), which ranges from Mexico southward to Brazil. It reaches a maximum length of 6 ft (1.8 m). It lives in trees, especially trees overhanging water, into which it will plunge if disturbed. It is greenish, with brown bands that form regular rings on the tail. It primarily eats tender leaves and fruits but will also eat small birds and crustaceans. Species of the southwestern U.S. and Mexico include the chuckwalla {Sauromalus obesus) and desert iguana {Dipsosaurus dorsalis).

Iguazu Falls or Iguacu \,e-gw3-'su\ FaWs, formerly Victoria Falls

A series of cataracts on the Iguazu River near the border between Argen¬ tina and Brazil. The horseshoe-shaped falls were discovered by Alvar Nunez Cabeza de Vaca in 1541. They vary between 200 and 269 ft (60 and 82 m) in height and extend for 1.7 miles (2.7 km)—nearly three times wider than North America’s Niagara Falls —and are divided into 275 waterfalls or cataracts. The scenic beauty and wildlife of the falls are pro¬ tected by two separate national parks: Iguazu National Park (1939) in Brazil and Iguazu National Park (1934) in Argentina. Both parks were designated UNESCO World Heritage sites in 1984 and 1986, respectively.

Iguazu Falls on the Iguazu River at the Argentina-Brazil border.

© R. MANLEY/SUPERSTOCK

Iguazu River or Iguacu River River, southern Brazil and northeast¬ ern Argentina. It winds westward for 820 mi (1,320 km) before joining

the Parana River at the point where Argentina, Brazil, and Paraguay meet. Although sections of the river are navigable, it is known chiefly for the scenic Iguazu Falls. Near the falls a major portion of the river tumbles into a chasm called the Garganta del Diablo (“Devil’s Throat”), which has been described as “an ocean plunging into an abyss.”

Iguvine \I-'gu-v!n\ Tables Set of seven inscribed bronze tables writ¬ ten in the Umbrian language and found in 1444 at Iguvium (modern Gub- bio, Italy). Some are written in the Umbrian script and others in the Latin alphabet; they probably date from the 3rd to 1st century bc. The tables record liturgy, sacred rites, and regulations of the Fratres Atiedii, a broth¬ erhood of priests, and are of great value for the study of ancient Italic language and religion.

Ihara Saikaku \e- , ha-ra- , sl-,ka-ku\ or Ibara \e-'ba-ra\ Saikaku known as Saikaku orig. Hirayama Togo (b. 1642, Osaka, Japan—d. Sept. 9, 1693, Osaka) Japanese poet and novelist. He first won fame for his speed in composing haikai (humorous linked-verse poems), once pro¬ ducing 23,500 in a day. He is best known for his novels, including The Life of an Amorous Man (1682) and Five Women Who Loved Love (1686) in which he enchanted readers with racy accounts of the amorous and financial affairs of the merchant class and the demimonde. He was one of the brilliant figures of the 17th-century revival in Japanese literature.

li Naosuke \'e-e-na-'os-ka\ (b. Nov. 29, 1815, Hikone, Japan—d. March 24, 1860, Edo [now Tokyo]) Japanese daimyo and statesman who made the last attempt to reassert the traditional political role of the sho- gunate (military ruler). In response to Commodore Matthew Perry’s demand that Japan end its centuries-old policy of isolation, Ii favoured developing relations. The Tokugawa shogun signed the Perry Convention (1854), which opened two ports to U.S. ships, exposing the country to Western influence, and began negotiations with Townsend Harris over trade. In an unusual move, the shogunate had sought the emperor’s con¬ sent to the treaty; when antitreaty forces blocked approval, Ii, as head of the shogunal governing body, authorized the signing. This outraged many daimyo; when Ii silenced them, he was beheaded by assassins. See also Tokugawa period; Meiji Restoration.

lio Sogi Vso-ge\ or Sogi (b. 1421, Japan—d. Sept. 1, 1502, Hakone) Japanese poet. Sogi was a Zen monk in Kyoto before becoming, in his 30s, a professional renga (linked-verse) poet. He is considered the great¬ est master of renga because of two sequences, Minase sangin (1488; “Three Poets at Minase”) and Yuyama sangin (1491; “Three Poets at Yuyama”), in each of which poets led by Sogi took turns at composing short stanzas (links) to form a single poem with many shifts of mood and direction. The foremost poet of his age, he left more than 90 works, including anthologies, diaries, poetic criticism, and manuals.

Ijoid languages The smallest branch of the huge Niger-Congo lan¬ guage family. The Ijoid languages are found in the relatively narrow coastal Niger River delta region of Nigeria. They consist of a language cluster, Ijo, which is spoken by about two million people, and the solitary Defaka, spoken by very few. The Ijo were among the first West Africans to have contact with Europeans, and the Ijo language is believed to be one of the first Nigerian languages written.

IJssel River Va-sol,\ English Vl-soL River, in The Netherlands. An important distributary of the Rhine River, it leaves the Lower Rhine (Neder Rijn) just southeast of Arnhem and flows northeastward for 70 mi (110 km) to enter the IJsselmeer. Zutphen, Deventer, and Zwolle are important cities along its course.

IJsselmeer Va-sol-.merX English Lake Ijssel Shallow freshwater lake, northern and central Netherlands. Fed by the IJssel River, it was formed from the southern part of the former Zuiderzee by a dam, which separates it from both the Waddenzee and the North Sea. It previously had a total area of 1,328 sq mi (3,440 sq km), though this has been reduced by rec¬ lamation projects that have increased the land area of The Netherlands by more than 600 sq mi (1,600 sq km). Regulated by sluices, the formerly brackish water has been replaced by fresh water from the IJssel River, and eel fisheries have been established.

ijtihad \,ij-te-'had\ In Islamic law, the analysis of problems not covered precisely in the Qur’an, the Hadith, or the scholarly consensus called the ijmcf. In the early Muslim scholarly community, every jurist had the right to exercise such original thinking, but the growth of legal schools prompted Sunnite Muslim authorities to declare that the principal legal issues had been settled by the 10th century. ShTite Muslims have always

© 2006 Encyclopaedia Britannica, Inc.

928 I Ike Taiga ► illuminated manuscript

recognized ijtihad, and jurists considered learned enough for this kind of analysis have great authority. In the 20th century an attempt was made to restore ijtihad among Sunnites to help Islam adapt to the modern world.

Ike Taiga \'e-ke-'tl-ga\ orig. Matajiro (b. June 6, 1723, Kyoto, Japan—d. May 30, 1776, Kyoto) Japanese painter. From an early age he was taught calligraphy and the Chinese classics. He helped establish the bunjin-ga style of painting (see literati), originally a Chinese style. His works consist of landscapes and portraits, including the screen pictures The Five Hundred Disciples of Buddha and a series of illustrations for Juben jugicho (1771; “Ten Advantages and Ten Pleasures Collection”), albums based on the poems of Li Liweng of the Qing dynasty (1644- 1911). Ike became one of the leading calligraphers of the Edo culture.

ikebana \,i-ka-'ba-n3\ Japanese art of flower arranging. It was intro¬ duced in Japan in the 6th century by Chinese Buddhist missionaries, who had formalized the ritual of offering flowers to the Buddha. The first school of flower arranging in Japan was founded in the early 7th century. The art is based on harmony of simple linear construction and appreciation of the subtle beauty of flowers and natural material (branches, stems). Sev¬ eral major schools, with differing histories and theories of artistic style, exist to this day. In its highest form, ikebana is spiritual and philosophi¬ cal in nature, but in modern Japan it is more often practiced as a sign of refinement by marriageable young women or older matrons.

Ikhwan \ik-'wan\ Arabic "Brethren" Religious and military broth¬ erhood that helped I BN Sa'ud unite the Arabian Peninsula. First organized in 1912, its members were settled in colonies around oases in an effort to break down tribal loyalties and force the Bedouin to abandon their nomadic way of life. They also embraced the arch-traditionalist Islamic principles of Muhammad ibn ‘Abd al-WAHHAB. From 1919 they won many victories in Arabia and Iraq, with conquests including Mecca and Medina. By 1926 the Ikhwan were becoming uncontrollable, attacking Ibn Sa'ud for inno¬ vations such as telephones and automobiles. They staged a bloody revolt, which was not put down until 1930, and then only with British help. Members who had remained loyal were eventually absorbed into the National Guard of Saudi Arabia.

Ikhwan al-MuslimDn, al- See Muslim Brotherhood

Ikhwan al-Safa’ \ik-'wan-as-sa-'fa\ Secret Arab brotherhood founded in Basra, Iraq, in the 10th century. The beliefs of the group diverged sharply from orthodox Islam, incorporating elements of Neoplatonism, Gnosticism, astrology, and the occult sciences. The brotherhood is best known for having produced a philosophical and religious encyclopedia, Epistles of the Brethren of Purity and Loyal Friends , whose purpose was to provide enlightenment that would purify the soul and provide happi¬ ness in the next life.

ikki \'ik-e\ Peasant uprisings in Japan beginning in the Kamakura period (1192-1333) and continuing through the Tokugawa period (1603-1867). Though the welfare of the city dweller improved during Tokugawa (Edo) times, the welfare of poor peasants worsened: excessive taxation and ris¬ ing numbers of famines drove them first to peaceful and then to violent demonstrations. They sometimes received redress for particular hardships, but their spokesmen would forfeit their lives for their audacity.

II Rosso See Giovanni Battista Rosso ilang-ilang See ylang-ylang

ileitis \,i-le-'i-t3s\ Chronic inflammation of part of the small intestine or large intestine (strictly, of the ileum). A more serious type, regional ileitis (Crohn disease), involves both small and large intestines. Ileitis symp¬ toms include chronic or intermittent, sometimes bloody, diarrhea and abdominal cramps. Fever, weight loss, and anemia may occur. Crohn dis¬ ease may involve progressive deterioration. Obstructions or abnormal connections between loops of intestine may develop. Simple ileitis has short-term causes, and many patients recover completely. In Crohn dis¬ ease, which may result from an autoimmune defect, remissions and relapses continue for years, causing the intestine’s wall to thicken, its channel to narrow, and its lining to ulcerate. X-ray films or colonoscopy showing these features are diagnostic. Drug treatment may help, but there is no known cure, and the disease often requires removal of part of the intestine.