Britannica Concise 2005

Pemex ► Pendleton Civil Service Act I 1467

medication, and sexual abstinence until the infection disappears. Sexual partners must also be treated to prevent reinfection.

Pemex officially Petroleos Mexicanos Mexico’s state-owned oil company. In 1938 Pres. Lazaro Cardenas nationalized 17 foreign oil com¬ panies to create Pemex, the largest Latin American petroleum company and a major world exporter of fossil fuel. Pemex engages in exploration, production, refining, transportation, storage, distribution, and sales of oil and natural gas. In the 1970s promising oil discoveries gave rise to a national spending spree, led by the flamboyant Pres. Jose Lopez Portillo and financed by massive borrowing. Crude-oil production tripled, but when the international price of oil collapsed in 1981, Lopez Portillo raised Mexican oil prices. The country was virtually bankrupt within one year. Economic reforms have since contributed to greater stability. At the turn of the 21st century, Pemex accounted for nearly 40% of the Mexican gov¬ ernment’s income.

pen drawing Artwork executed wholly or in part with pen and ink, usually on paper. It is fundamentally a linear method of making images. Artists who wish to suggest three-dimensional forms use hatching and cross-hatching or washes of colour laid onto the drawing with a brush. The three most common types of ink are black carbon ink, the finest type being Chinese ink or the modern India ink; brown ink, which was popu¬ lar with the Old Masters; and iron gall, a chemical ink. The three pen types are quill, reed, and metal. Quill pens were most popular for their flexibility and ability to be sharpened to extreme fineness. Steel became the predominant pen type by the 20th century.

penal colony Distant or overseas settlement established to punish criminals with forced labour and isolation from society. Such colonies were developed mostly by the English, French, and Russians. Britain sent criminals to its American colonies until the Revolutionary War; Australia was principally a penal colony from its colonization until the mid-19th century. French Guiana, site of a French penal colony, was infamous for its inhumanity; Devil's Island was still operating during World War II. Russian penal colonies were established in Siberia under the tsars but were most widely used during the Stalin era. Notorious for their harsh punish¬ ments and underfeeding, most penal colonies have now been abolished.

Penang \po-'naq\ Malay Pinang Island (pop., 2000 prelim.: 1,225,501), Malaysia, off the northwestern coast of the Malay Peninsula, part of the state of Pulau Pinang. The capital and chief port is George Town (pop., 2000 prelim.: 180,573), in the northeast. British colonization began in 1786. In 1826 Penang (known until 1867 as Prince of Wales Island) combined with Malacca and Singapore to form the Straits Settle¬ ments. From the mid-19th century it was a market for tin and rubber. In 1948 it became part of the Federation of Malaya, later Malaysia. In the late 20th century it became Malaysia’s prime tourist centre, with resort hotels mainly on the northern coast at Batu Feringgi.

Penates \po-'na-tez, po-'na-tez\ Roman household gods. They were wor¬ shiped privately as protectors of the household and also publicly as pro¬ tectors of the Roman state. They were sometimes associated with other deities of the house, such as Vesta, and their name was often used inter¬ changeably with that of the Lares. Each house had a shrine with their images, which were worshiped at the family meal and on special occa¬ sions. Offerings were portions of the regular meal or of special cakes, wine, honey, and incense. The number and precise identities of the Penates were a puzzle even to the ancients.

pencil drawing Drawing executed with a pencil, an instrument made of graphite enclosed in a wood casing. Though graphite was mined in the 16th century, its use by artists is not known before the 17th century. In the 17th—18th century, graphite was used primarily to make preliminary sketches for more elaborate work in another medium, seldom for finished works. By the late 18th century, an ancestor of the modern pencil was constructed by inserting a rod of natural graphite into a hollow cylinder of wood. Pencil rods produced from mixtures of graphite and clays, true prototypes of the modem graphite pencil, were introduced in 1795. This improvement allowed for better control and encouraged wider use. The great masters of pencil drawing kept the elements of a simple linearism with limited shading, but many artists in the 18th—19th century created elaborate effects of light and shade by rubbing the soft graphite particles with a tightly rolled paper or chamois.

pendant or pendent In architecture, a sculpted ornament suspended from a vault or ceiling, especially an elongated boss (carved keystone) at

the junction of the intersecting ribs of the fan vaulting associated with the English Perpendicular style. In stone ceilings, the use of pendant vaulting was a solution to the difficulty of adapting fan vaulting to very wide church naves. Strong transverse arches were made to span the area, and these in turn supported the elongated keystones. Intermediate rib and panel vaults sprang from these pendants.

pendant Ornament suspended from a bracelet, earring, or necklace and derived from the primitive practice of wearing amulets or talismans around the neck. The practice dates from the Stone Age, when pendants consisted of objects such as teeth, stones, and shells. Commemorative and decorative pendants were com¬ mon in ancient Egypt, Greece, and Rome. In the Middle Ages reliquar¬ ies, or devotional pendants, and crosses were created with jewels. By the beginning of the 16th century,

Renaissance artists were creating pendants for decorative rather than religious use. The late 19th-century Art Nouveau movement often fea¬ tured women’s figures, butterflies, or flowers on pendants.

pendentive In architecture, a tri¬ angular segment of a spherical sur¬ face that forms the transition between the circular plan of a dome and the polygonal plan of its supporting structure. The problem of placing a round dome on a square base assumed growing importance to Roman builders, but it remained for Byzantine architects to recognize the possibilities of the pendentive and fully develop it (see Hagia Sophia). One of the great architectural inventions of all time, the pendentive became very impor¬ tant in the Renaissance and Baroque periods. As a result of Byzantine influence, pendentives are also frequent in Islamic architecture. The vault¬ ing form in which the curve of the pendentive and dome is continuous is known as a pendentive dome.

Penderecki \,pen-d3-'ret-ske\, Krzysztof (b. Nov. 23, 1933, Debica, Pol.) Polish composer and conductor. He studied composition at the Krakow Conservatory and would later serve as its director (1972-87). His early music (1960-74) involved dense note clusters and unorthodox sounds, and he developed his own musical notation to convey the desired effects, resulting in vivid works that attracted international attention, including Threnody for the Victims of Hiroshima (1960), Stabat Mater (1962), the St. Luke Passion (1963-65), and the opera The Devils of Lou- dun (1969). After 1975 he embraced a more traditional approach with works such as the opera Paradise Lost (1978), concertos for violin (1977), cello (1982), and viola (1983), and Lux aeterna (1983).

Pendergast, Thomas J(oseph) (b. July 22, 1872, St. Joseph, Mo., U.S.—d. Jan. 26,1945, Kansas City, Mo.) U.S. politician. He was active in municipal politics in Kansas City, Mo., and became the political boss of the city’s Democrats by 1916. His political machine dominated city and state politics for almost 25 years and influenced national Democratic conven¬ tions. He helped Harry S. Truman in his early political career. Attacked by opponents for allowing corrupt practices in Kansas City, he was convicted of income-tax evasion in 1939 and served one year in prison.

Pendleton, George (Hunt) (b. July 29, 1825, Cincinnati, Ohio, U.S.—d. Nov. 24, 1889, Brussels, Belg.) U.S. politician. He served in the U.S. House of Representatives from 1857 to 1865 and was the unsuc¬ cessful Democratic candidate for vice president (with George B. McClel¬ lan) in 1864. A member of the Greenback movement, he advocated the Ohio Idea for redeeming American Civil War bonds. From 1879 to 1885 he served in the U.S. Senate, where he sponsored the Pendleton Civil Service Act. He served as minister to Germany from 1885 to 1889.

Pendleton Civil Service Act (1883) U.S. legislation establishing the modern civil-service system of permanent federal employment based on merit. Public demand for civil-service reform to replace the system based on political party affiliation (the spoils system) resulted in a bill sponsored by Sen. George Pendleton, which provided for selection of government employees by competitive examination administered by a civil-service

Art Nouveau pendant by L. Gautrait, c. 1900; in the Schmuckmuseum, Pforzheim, Ger.

COURTESY OF THE SCHMUCKMUSEUM, PFORZHEIM, GER

© 2006 Encyclopaedia Britannica, Inc.

1468 i pendulum ► Pennsylvania

commission. Only 10% of government jobs were originally covered by the law, but successive Congresses expanded its scope to include more than 90% of federal employees.

pendulum Body suspended from a fixed point so that it can swing back and forth under the influence of gravity. A simple pendulum consists of a bob (weight) suspended at the end of a string. The periodic motion of a pendulum is constant, but can be made longer or shorter by increasing or decreasing the length of the string. A change in the mass of the bob alone does not affect the period. Because of their constancy, pendulums were long used to regulate the movement of clocks. Other, special kinds of pendulums are used to measure the value of g, the acceleration due to gravity, and to show that the earth rotates on its axis (see Foucault pen¬ dulum).

peneplain Vpe-n3-,plan\ Gently undulating, almost featureless plain near sea level. This would form, theoretically, by various erosional pro¬ cesses that reduce areas of initially high relief produced by active uplift to areas of virtually no relief. The lack of present-day peneplains tends to discredit the theory, but some geomorphologists propose that large areas of low relief at high altitude in some mountains are evidence of uplifted peneplains. Others question whether the dynamic relationship between erosion and rock type would ever allow the development of a peneplain, even over very long timespans.

Peneus River See Pinios River

penguin Any of 17 species (order Sphenisciformes) of flightless sea¬ birds that breed mainly on islands in subantarctic waters and on cool coasts of Africa, Australia, New Zealand, and South America. A few spe¬ cies inhabit temperate regions, and the Galapagos penguin (Spheniscus mendiculus) lives in the equatorial tropics off South America. Species dif¬ fer mainly in size and head pattern; all have a dark back and a white belly. The smallest species, the little blue penguin {Eudyptula minor), is about 14 in. (35 cm) tall; the largest, the emperor penguin (Aptenodytes for- steri), is almost 4 ft (120 cm) tall. At sea for weeks at a time, flocks feed on fish, squid, and crustaceans.

penicillin Antibiotic derived from the Penicillium mold. It was discovered in 1928 by Alexander Fleming; by 1940, Howard Walter Florey, Ernst Boris Chain, and others had produced commercial quantities that proved vital to the treatment of war casualties, making penicillin the first successful antibiotic for human bacterial infections. Many natural and semisynthetic (ampicillin, amoxicillin) variants have since been produced. All work by inhibiting the enzymes responsible for bacterial cell wall synthesis (and therefore do not work against microorganisms without cell walls or with certain variant cell walls; e.g., the tuberculosis bacillus). Among the bac¬ teria susceptible to penicillin are those causing strep throat, spinal men¬ ingitis, gas gangrene, and syphilis. Overuse has led to drug resistance in some strains. Penicillin’s chief side effect is allergy, which can be life- W threatening.

wm Penicillium V.pe-ns-'si-le-omV Any blue or green mold in the genus Pen-

!■ icillium (kingdom Fungi; see fungus). Common on foodstuffs, leather, and

fabrics, they are economically important in producing antibiotics (see peni- wm cillin), organic acids, and cheeses such as English Stilton, Italian Gor-

J gonzola, and French Roquefort.

Peninsular War (1808-14) Part of the Napoleonic Wars, fought on the Iberian Peninsula. After French forces occupied Portugal (1807) and Napoleon installed his brother Joseph Bonaparte as king of Spain (1808), a rebellion in Madrid began what was called in Spain “the War of Inde¬ pendence,” and insurrections soon erupted in other cities. By 1810 the French overcame the Spanish rebels in Madrid and elsewhere in Spain. Meanwhile, the British under the future duke of Wellington landed in Portugal (1808), where they fought the French in inconclusive campaigns until 1812. After Napoleon withdrew French forces to bolster his invasion of Russia, Wellington began his gradual advance into Spain. The British victory at the Battle of Vitoria (1813) and their march into southwestern France forced the French to withdraw from Spain and to reinstall Ferdi¬ nand VII as king (1814).

penis Male sex organ, which also provides the channel for urine to leave the body. Three long columns of tissue extend through its length, covered by elastic tissue and a thin layer of skin. One expands at the tip into a mushroom-shaped structure (glans penis) and contains the urethra (see urinary system), which ends in a slitlike opening. In sexual arousal, blood fills spaces in the tissue, and blood vessels constrict to hold it there,

enlarging and hardening the penis in an erection. The foreskin, a circular fold of skin covering the glans, is often removed (see circumcision). See also REPRODUCTIVE SYSTEM.

Penn, Irving (b. June 16, 1917, Plainfield, N.J., U.S.) U.S. photogra¬ pher. He aspired to be a painter but at 26 took a job designing photo¬ graphic covers for Vogue and soon was established as a fashion photographer. His austere fashion images communicated elegance and luxury through compositional refinement and clarity of line rather than through the use of elaborate props and backdrops. He branched out into portraiture after World War II and became much admired as a portraitist of celebrities. In his portraits the subject is usually posed before a bare backdrop and photographed in natural northern light. The resulting images combine simplicity and directness with great formal sophistication.

Penn, William (b. Oct. 14, 1644, London, Eng.—d. July 30, 1718, Buckinghamshire) English Quaker leader and founder of Pennsylvania. Expelled from Oxford for his Puritan beliefs, he was sent to manage the family estates in Ireland, where he joined the Society of Friends in 1667. He was imprisoned four times for stating his Quaker beliefs in print and in speech; one of his trials resulted in the precedent-setting Bushell’s Case, which established the independence of juries. In The Great Case of Liberty of Conscience (1670), Penn advocated religious toleration and envisioned a colony based on religious and political freedom. On his father’s death, he inherited his estates and his influence with Charles II, who granted him a vast province on the Delaware River in payment for debts owed his father. In 1682 he drafted a Frame of Government that established freedom of worship in the settlement. Upon his arrival later that year, he negotiated a series of treaties with the local Indians. In 1684 he traveled to England to defend his interests against claims by neigh¬ bouring Maryland. With the accession of his friend the duke of York as James II, he secured the release of imprisoned Quakers. He returned to Pennsylvania in 1699, where he wrote the Charter of Privileges, which allowed the assembly greater autonomy. The years after his return to England in 1701 were clouded by debt and illness.

Penney, J(ames) C(ash) (b. Sept. 16, 1875, Hamilton, Mo., U.S.—d. Feb. 12, 1971, New York, N.Y.) U.S. merchant. He became a partner in a dry-goods store in Wyoming in 1902 and five years later bought out his partners’ shares to launch what became the J.C. Penney Co. His stores offered a wide variety of inexpensive merchandise, and he offered profit- sharing plans, first to managers and later to all employees. By 1929 the company had 1,392 stores across the U.S., and at the time of Penney’s death it was the second largest merchandiser in the country, behind Sears, Roebuck and Co.

Pen nines Vpe-.nlnzX Upland mass, northern England. The Pennines extend south from Northumberland to Derbyshire; the highest point is Cross Fell, at 2,930 ft (893 m). Water action has developed underground cav¬ erns in the uplands’ limestone, which is extensively quarried. Sheep farm¬ ing is also important. Archaeological remains in the area include the ancient Roman Hadrian's Wall.

Pennsylvania officially Commonwealth of Pennsylvania

State (pop., 2000: 12,281,054), middle Atlantic region, U.S. It covers 45,333 sq mi (117,412 sq km); its capital is Harrisburg. The state is bounded on the north by Lake Erie and New York; on the east by New York and New Jersey; on the south by Delaware, Maryland, and West Virginia; and on the west by the panhandle of West Virginia and by Ohio; the Delaware River forms part of the eastern boundary. The Monongahela River unites with the Allegheny River at Pittsburgh to form the Ohio River. The area was inhabited by Indian peoples, including the Shawnee and Delaware, when Europeans arrived in the 17th century. In 1664 the English seized control of the region, and in 1681 the English king granted a char¬ ter to William Penn, who established a Quaker colony based on religious tolerance in 1682. Much of the fighting of the French and Indian War took place there. The first and second Continental Congresses met in Philadel¬ phia, and the Declaration of Independence was signed there in 1776. One of the original states of the Union, it was the second state to ratify the U.S. Constitution in 1787. During the American Civil War it was a centre of military activity (see Battle of Gettysburg). The postwar period brought great economic, industrial, and population growth, consolidating the state’s position as a major commercial power. It is one of the most pros¬ perous states, with an economy based on farming, mining, manufactur¬ ing, and high technology. The state continues to produce much of the

© 2006 Encyclopaedia Britannica, Inc.

Pennsylvania ► Pentium I 1469

nation’s specialty steel and an abundance of coal. Philadelphia and Pitts¬ burgh are major ports with fine educational, cultural, and musical insti¬ tutions.

Pennsylvania, University of U.S. private university in Philadel¬ phia, a traditional member of the Ivy League. Founded in 1740 as a charity school, it became an academy in 1753, with Benjamin Franklin as president of the first board of trustees. With the founding of the first medical school in North America (1765), it became a university. Today, in addition to its college of arts and sciences and its medical school, it includes a college of general studies and schools of business (the Wharton School), communi¬ cation (the Annenberg School), education, engineering, fine arts, law, nurs¬ ing, dentistry, veterinary medicine, and social work. Its institutes include the Wistar Institute of Anatomy and Biology and the Phipps Institute of Genetics and Community Diseases. The University Museum (of archaeol¬ ogy and ethnology) is a teaching and research organization.

Pennsylvania Railroad Co. Former U.S. railroad. It was chartered in 1846 by the Pennsylvania legislature to build a line between Harris¬ burg and Pittsburgh, and its passenger service began two years later. By purchasing the Pittsburgh, Fort Wayne and Chicago Railway in 1856, the company extended its service to Chicago. After the Civil War it expanded to St. Louis, Mo., and Cincinnati, Ohio, in the west and Norfolk, Va., in the south, with 10,000 mi (16,000 km) of track at its greatest extent. It began to lose money in the mid 20th century, and in 1968 it merged with its competitor, the New York Central, to form the Penn Central Transpor¬ tation Co. Penn Central declared bankruptcy in 1970; its passenger ser¬ vice was taken over by Amtrak in 1971 and its assets by Conrail in 1976. See also J. Edgar Thomson.

Pennsylvania State University U.S. public state system of higher education with a main campus in University Park and numerous other campuses and locations, including the Milton S. Hershey Medical Center in Hershey and the Dickinson School of Law in Carlisle. The university originated with the charter of the Farmers’ High School in 1855 and was designated the commonwealth’s land-grant college in 1862. It took its current name only in 1953. Research facilities include the Biotechnology Institute, the Center for Applied Behavioral Science, and the Center for Particle Science and Engineering.

Pennsylvanian Period In North America, the interval of geologic time roughly equivalent to what is internationally designated the Late Carboniferous Period (323-290 million years ago). Because the rocks that originated during this span of time are widespread in the state of Penn¬ sylvania, some U.S. geologists favour the term over Late Carboniferous Period, which was first adopted in Europe.

Penobscot \po-'nab-sk3t\ River River, central Maine, U.S. The Penob¬ scot, which flows south into Penobscot Bay, is the state’s longest river— about 350 mi (560 km). It is navigable for 60 mi (97 km) to Bangor. Once an important source of salmon, it has become economically important to the lumber, pulp, and paper industries because of its hydropower facili¬ ties. Navigated by French and English voyagers in the early 17th century, it was named for the Penobscot Indians.

penology \pe-'na-l3-je\ Branch of criminology dealing with prison man¬ agement and the treatment of offenders. Penological studies have sought to clarify the ethical bases of punishment, along with the motives and purposes of society in inflicting it; differences throughout history and between nations in penal laws and procedures; and the social conse¬ quences of the policies in force at a given time. Influential historical works have included Cesare Beccaria’s On Crimes and Punishments (1764), Jer¬ emy Bentham’s “Panopticon” scheme (c. 1800), Cesare Lombroso’s Crime (1876), and Michel Foucault’s Discipline and Punish (1975).

pension Series of periodic money payments made to a person who retires from employment because of age, disability, or the completion of an agreed span of service. The payments generally continue for the rest of the recipient’s natural life, and they are sometimes extended to a widow or other survivor. Military pensions have existed for many centuries; pri¬ vate pension plans originated in Europe in the 19th century. There are two basic types of pension plans: defined contribution and defined benefit. A defined contribution plan invests a defined amount each pay period. The individual may have some discretion as to how the money is invested. The benefit, the amount of the pension, depends on the success of those investments. A defined benefit plan pays a known amount according to some formula, but the amount invested in the fund may vary. Pensions

may be funded by making payments into a pension trust fund or by the purchase of annuities from insurance companies. In plans known as mul¬ tiemployer plans, various employers contribute to one central trust fund administered by a joint board of trustees.

Pentagon Huge five-sided building (1941-43) in Arlington, Va., that is the headquarters of the U.S. Department of Defense. Designed by George Edwin Bergstrom, it was, on its completion, the world’s largest office building, covering 34 acres (14 hectares) and offering 3.7 million sq ft (about 344,000 sq m) of usable floor space for as many as 25,000 work¬ ers. Built of structural steel and reinforced concrete with some limestone facing at a cost of $83 million, the five-story structure actually consists of five concentric pentagons, with 10 spokelike corridors connecting the whole. In 2001 more than 180 people were killed and many more were injured when part of the Pentagon’s southwest side was destroyed in the September 11 attacks.

Pentagon Papers Secret documents detailing the U.S. role in Indoch¬ ina from World War II to 1968. The U.S. Defense Department commis¬ sioned the study; a project associate, Daniel Ellsberg, who was opposed to U.S. participation in the Vietnam War, leaked details of the documents to the press. In June 1971 The New York Times began publishing articles based on the study. The U.S. Justice Department, citing national security, obtained a temporary court order halting publication. The U.S. Supreme Court ruled that the government had failed to justify restraint of publica¬ tion, and the documents were published widely, fueling debate over the country’s Vietnam policy.

Pentateuch See Torah

pentathlon Athletic contest entailing five distinct types of competi¬ tions. In the ancient Olympic Games, the pentathlon included a sprint, the long jump, discus throw, javelin throw, and a wrestling match. A modified version (with a medium-distance race substituted for the wrestling match) was included in the revived Olympic Games (1912-24). The modern, or military, pentathlon, included in the Olympics from 1912 and made a team event in 1952, includes an equestrian steeplechase, fencing, pistol shoot¬ ing, a freestyle swim, and a cross-country run. Women’s pentathlon com¬ petition (shot put, high jump, hurdling race, sprint, and long jump) was replaced in 1981 by the heptathlon.

Pentecost (from Greek pentecoste, “fiftieth day”) Christian festival commemorating the descent of the Holy Spirit on the disciples of Jesus, occurring on the Jewish Pentecost, after Jesus’ death, resurrection, and ascension. The disciples began to speak in the many languages of the people assembled there, a sign that the disciples should spread the Chris¬ tian message throughout the world. Jewish Pentecost was a thanksgiving feast for the first fruits of the wheat harvest and was associated with remembrance of God’s gift of the Law to Moses on Mount Sinai. Chris¬ tian Pentecost is celebrated on the Sunday concluding the 50-day period following Easter. It is also the name of the Jewish celebration of Shavuot (“Festival of Weeks”).

Pentecostalism Protestant religious movement that originated in the U.S. in the 19th-20th century. It is characterized by a belief that all Chris¬ tians should seek a postconversion religious experience called baptism with the Holy Spirit. The experience corresponds to the descent of the Holy Spirit on the twelve Apostles (Pentecost) and is evidenced by speaking in tongues, prophesying, and healing. Pentecostalism grew out of the 19th- century Holiness movement and shares its emphasis on biblical literalism, conversion, and moral rigor. The charismatic movement in Roman Catho¬ lic and mainstream Protestant denominations represents the same spirit. Today there are many Pentecostalist denominations in the U.S. and around the world, including the Assemblies of God. Penetcostalism has been espe¬ cially successful in the Caribbean, Latin America, and Africa.

penthouse Enclosed area on top of a building. A penthouse can be an apartment on the roof or top floor of a building or a structure on the roof housing the top of an elevator shaft, air-conditioning equipment, or stairs leading to the roof. A penthouse is usually set back from the vertical face of a building, but as a real-estate term, penthouse may refer to any top floor, regardless of setbacks. Though the word now often suggests a luxu¬ rious apartment with a panoramic view, historically a penthouse was a lean-to, shed, or other small structure attached to a comparatively large building.

Pentium Family of microprocessors developed by Intel Corp. Introduced in 1993 as the successor to Intel’s 80486 microprocessor, the Pentium

© 2006 Encyclopaedia Britannica, Inc.

1470 I Penutian languages ► peptic ulcer

contained two processors on a single chip and about 3.3 million transis¬ tors. Using a CISC (complex instruction set computer) architecture, its main features were a 32-bit address bus, a 64-bit data bus, built-in floating¬ point and memory-management units, and two 8KB caches. It was avail¬ able with processor speeds ranging from 60 megahertz (MHz) to 200 MHz. The Pentium quickly became the processor of choice for personal computers. It was superseded by ever faster and more powerful proces¬ sors, the Pentium Pro (1995), the Pentium II (1997), the Pentium III (1999), and the Pentium 4 (2000).

Penutian languages \p9-'nu-te-9n\ Hypothetical superfamily of North American Indian languages that unites a number of languages and language families mainly of the far western U.S. and Canada. The Penu¬ tian hypothesis was proposed by Roland B. Dixon and Alfred L. Kroeber in 1913 and refined by Edward Sapir in 1921. Like the Hokan hypothesis (see Hokan languages), it attempted to reduce the number of unrelated language families in one of the world’s most linguistically diverse areas. At its core was a group of languages spoken along California’s central coast and in the Central Valley, including Ohlone (Costanoan), Mi wok, Wintuan, Maidu, and Yokuts. Sapir added Oregon Penutian (languages once spoken in eastern Oregon), Chinookan (spoken along the lower Columbia River), Plateau Penutian (languages of Plateau Indian peoples), Tsimshian (spoken in western British Columbia), and Mexican Penutian (spoken in southern Mexico). Aside from the Mexican group, all the lan¬ guages are today either extinct or spoken almost exclusively by older adults. Though the hypothesis remains unproven, at least some languages of the group are probably related to each other.

Penzias \'pent-se-9s\, Arno (Allan) (b. April 26, 1933, Munich, Ger.) German-bom U.S. astrophysicist. His family fled Nazi Germany, and he received his Ph.D. from Columbia University, after which he joined Bell Telephone Laboratories, where he worked with Robert W. Wilson moni¬ toring radio emissions from a ring of gas around the Milky Way Galaxy. The two detected an unexpected uniform background static that suggested a thermal energy throughout the universe at a temperature of about -454 °F (-269 °C), which most scientists now agree is residual cosmic back¬ ground radiation stemming from the big bang explosion billions of years ago, from which the universe was created. They shared a 1978 Nobel Prize with Pyotr Kapitsa (1894-1984) for their work. In 1981 Penzias became a vice president at Bell Laboratories, retiring in 1998.

peonage Ype-a-nijV Form of involuntary servitude, the origins of which date to the Spanish conquest of Mexico, when the conquerors forced the poor, especially Indians, to work for Spanish planters and mine operators. In the U.S., the word peon referred to workers compelled by contract to pay their creditors in labour. Though prohibited under U.S. federal law, peonage persisted in some southern states through state laws that made labour compulsory. Another form of peonage exists when prisoners sen¬ tenced to hard labour are farmed out to labour camps.

peony \'pe-o-ne\ Any of about 33 species of flowering plants in the genus Paeonia, sole genus of the family Paenoiaceae, found in Europe, Asia, and western North America and known for their large, showy blos¬ soms. Herbaceous peonies are perennials that grow to about 3 ft (1 m). Their annual stems bear large, glossy, much-divided leaves and produce large single and double flowers of white, pink, rose, and deep crimson. Tree peonies are shrubs about 4-6 ft (1.2-1.8 m) high with permanent rootstocks and woody stems that bear flowers varying in colour from white to lilac, violet, and red.

People's Liberation Army Unified organization of China’s land, sea, and air forces. With more than 2,000,000 troops, it is the largest mili¬ tary force of any country in the world. The People’s Liberation Army traces its roots to the 1927 Nanchang Uprising of the communists against the Nationalists. Initially called the Red Army, it grew under Zhu De from 5,000 troops in 1929 to 200,000 in 1933. Only a fraction of this force survived the Long March in retreat from the Nationalists. After rebuild¬ ing its strength, a large portion of it, the Eighth Route Army, fought with the Nationalists against the Japanese in northern China. After World War II the communist forces, renamed the People’s Liberation Army, defeated the Nationalists, making possible the formation of the People’s Republic of China in 1949. See also Lin Biao; Mao Zedong.

Peoria City (pop., 2000: 112,936), central Illinois, U.S. The city is situ¬ ated where the Illinois River widens to form Peoria Lake. The first settle¬ ment on the site was a French fort established in 1680 by the French explorer La Salle. Later settlements were by the French, Indians, and other

colonists. It was incorporated as a city in 1845. It is a major port, trade, and shipping centre for a large agricultural area. It is highly industrial¬ ized, and its products include earth-moving equipment and chemicals.

Pepin III See Pippin III

Pepin, Donation of See Donation of Pippin

pepper or garden pepper Any of many plants in the genus Cap¬ sicum of the NIGHTSHADE family, nota¬ bly C. annuum, C. frutescens, and C. boccatum, native to Central and South America and cultivated exten¬ sively throughout tropical Asia and the equatorial New World for their edible, pungent fruits. Red, green, and yellow mild bell or sweet pep¬ pers, rich in vitamins A and C, are used in seasoning and as a vegetable food. The pungency of hot peppers, including tabasco, chili, and cayenne peppers, comes from the compound capsaicin in the internal partitions of the fruit. The spice back pepper comes from an unrelated plant.

pepper, black See back pepper

Pepper, Claude (Denson) (b.

Sept. 8, 1900, Dudleyville, Ala.,

U.S.—d. May 30, 1989, Washington,

D.C.) U.S. politician. He practiced law in Florida before being elected to the U.S. Senate (1937-51), where he supported legislation that created Social Security, a minimum wage, and medical assistance for the elderly. Elected to the U.S. House of Repre¬ sentatives (1963-89), he chaired the committee on aging and sponsored legislation abolishing mandatory retirement in federal agencies and rais¬ ing the retirement age to 70 in the private sector (1968). In 1989 he was awarded the Medal of Freedom.

peppermint Strongly aromatic perennial herb (. Mentha piperita, mint family), source of a widely used flavouring. Native to Europe and Asia, it has been naturalized in North America. The stalked, smooth, dark green leaves and blunt, oblong clusters of pinkish lavender flowers are dried for use as a flavouring agent. Oil of peppermint is widely used to flavour confectionery, chewing gum, toothpastes, and medicines. The oil also contains menthol, long used medicinally as a soothing balm.

PepsiCo, Inc. U.S. conglomerate. The soft drink Pepsi-Cola was cre¬ ated by a pharmacist, Caleb D. Bradham, who gave his tonic its name (from Greek pepsis, “digestion”) in 1898 and incorporated the Pepsi-Cola Co. in 1902. After two bankruptcies and several reincorporations, the Pepsi-Cola trademark and assets were bought in 1931 by Charles G. Guth, who improved the formula and marketed a 12-ounce bottle for five cents with huge success. Pepsi-Cola merged with the soda-fountain chain Loft, Inc., in 1941, and in 1965 it merged with Frito-Lay, Inc., adopting its cur¬ rent name, PepsiCo, Inc. In the 1970s and ’80s PepsiCo bought restau¬ rant chains such as Pizza Hut, Taco Bell, and Kentucky Fried Chicken, but in 1997 it spun off its restaurant business into a separate company, Tricon Global Restaurants. In 2001 the Quaker Oats Co. merged with PepsiCo.

pepsin Powerful enzyme in gastric juice (see stomach) that partially digests proteins in food. Glands in the stomach lining make pepsinogen, a zymogen (enzyme precursor) converted to pepsin by the hydrochloric acid in gastric juice. Pepsin is active only in the acid environment of the stom¬ ach (pH 1.5-2.5 or less); it is ineffective in the intestine (pH 7, neutral). It is used commercially in some cheese making, in the leather industry to remove hair and residual tissue from hides, and in the recovery of silver from discarded photographic films by digesting the gelatin layer that holds the silver.

peptic ulcer Sore that develops in the mucous membrane of the stom¬ ach (more frequent in women) or duodenum (accounting for 80% of ulcers and more frequent in men) when its ability to resist acid in gastric juice is reduced. It causes burning ache and hungerlike pain. Ulcers can bleed, perforate the abdominal wall, or block the gastrointestinal tract. Stress and

Red peppers (Capsicum annuum ) from which paprika is made G.R. ROBERTS

© 2006 Encyclopaedia Britannica, Inc.

peptide ► Percy I 1471

diet were blamed until Helicobacter pylori bacteria and long-term use of aspirin and similar drugs were shown to be the two major causes. The former is treated with combination drug therapy and the latter by stop¬ ping the causative drugs if possible or with drugs that reduce acid pro¬ duction. A rare cause is Zollinger-Ellison syndrome, in which a tumour causes increased acid secretion. Cigarette smoking slows healing and pro¬ motes recurrence.

peptide Organic compound composed of a series of amino acids linked by peptide bonds (see covalent bond) between a carbon atom of one and a nitrogen atom of the next. Peptide chains longer than a few dozen amino acids are called proteins. Biosynthesis of peptides from a succession of amino acids carried by transfer RNA molecules takes place on ribosomes and is catalyzed and controlled by enzymes. Many hormones, antibiotics, and other compounds that participate in life processes are peptides.

Pepys \'peps\, Samuel (b. Feb. 23, 1633, London, Eng.—d. May 26, 1703, London) English diarist and public official. Born into a humble family, Pepys was appointed about 1659 as a clerk in the office of the Exchequer, where on Jan. 1, 1660, he began the diary for which he is chiefly known. He steadily improved his position, in time becoming sec¬ retary of the Admiralty, a member of Parliament, president of the Royal Society, trusted confidant of Charles II and James II, and friend of the great scholars of his age. His diary (pub¬ lished 1825), which he kept through 1669, presents a fascinating picture of the official and upper-class life in Restoration London, with vivid, hon¬ est accounts of ordinary as well as great events, including the Plague and the Great Fire of London.

Pequot \'pe-,kwat\ North Ameri¬ can Indian people now living in east¬ ern Connecticut, U.S. Pequot is an Algonquian language, and the name is derived from an Algonquian word meaning “destroyers.” Pequot sub¬ sistence was based on corn cultivation, hunting, and fishing. The people were at one time united with the Mohegan. For a brief period the Pequot lived amicably with the American colonists, but relations became strained as land pressures grew. Puritan clergymen encouraged violence against the Pequot as infidels, and in 1636 war broke out, resulting in large losses. Further destruction resulted when the remaining Pequot were placed under the control of other tribes. In 1655 the few remaining Pequot were resettled on the Mystic River. The two groups of Pequot number about

1 , 000 .

Perahia \p3-'ri-3\, Murray (b. April 19, 1947, New York, N.Y., U.S.) U.S. pianist. He was trained at the Mannes College of Music in New York City. He won the Leeds International Piano Competition by unanimous vote in 1972, and in 1975 he shared the first Avery Fisher Prize. From 1982 he was music director of the Aldeburgh Festival and made his home in England. He is best known for his sensitive recordings of Wolfgang Amadeus Mozart’s concertos, conducted from the keyboard.

Peranakan \,per-3-'na-k3n\ Any native-born Indonesian of mixed Indonesian and foreign ancestry. The term often refers to the Peranakan Chinese, the largest and most important Peranakan group, who formed a stable community by the mid-19th century, partly adopting the indigenous way of life and generally speaking the native tongue. By contrast, in the early 20th century a large wave of Chinese immigration created a Totok (foreign-bom) Chinese community. Unlike the Peranakans, the Totoks retained their own Chinese dialects and remained China-oriented.

perception Process of registering sensory stimuli as meaningful expe¬ rience. The differences between sensation and perception have varied according to how the terms are defined. A common distinction is that sen¬ sations are simple sensory experiences, while percepts are complex con¬ structions of simple elements joined through association. Another is that perception is more subject to the influence of learning. Though hearing, smell, touch, and taste perceptions have all been explored, vision has received the most attention. Structuralist researchers such as Edward Brad¬

ford Titchener focused on the constituent elements of visual perceptions, whereas Gestalt psychology has stressed the need to examine organized wholes, believing humans are disposed to identifying patterns. Visual objects tend to appear stable despite continually changing stimulus fea¬ tures (such as ambient light, perspective, ground vs. figure arrangement), which enables an observer to match a perceived object with the object as it is understood to exist. Perceptions may be influenced by expectations, needs, unconscious ideas, values, and conflicts.

Perceval Hero of Arthurian legend. His childlike innocence protected him from worldly temptation. In Chretien de Troyes’s 12th-century Le Conte du Graal, Perceval visits the castle of the wounded Fisher King and sees the Grail, but he fails to ask about it and therefore fails to heal the Fisher King. He subsequently sets out in search of the Grail and grows spiritually. In later Grail legend he was displaced by Galahad as the hero of the Grail quest but continued to play an important role. His story was told in Wolfram von Eschenbach’s 13th-century Parzifal, which provided the basis for Richard Wagner’s opera Parsifal (1882).

Perceval Vpar-ss-volX, Spencer (b. Nov. 1, 1762, London, Eng.—d. May 11, 1812, London) British prime minister (1809-12). He entered Parliament in 1796 and supported William Pitt’s policy of war with France. He served as attorney general (1802-06) and as chancellor of the Exche¬ quer (1807-09). As premier from 1809, he was noted as an efficient administrator but also for his opposition to religious tolerance. He was assassinated by a deranged man who had applied to him for redress of a complaint against the government.

perch Either of two species (family Percidae, order Perciformes) of popu¬ lar food and sport fishes: the Eurasian common perch {Perea fluviatilis) or the North American yellow perch (P flavescens). Some consider the two a single species. Both have one spiny and one soft-rayed dorsal fin. Perches are carnivores of quiet ponds, lakes, streams, and rivers. The common perch is greenish, with dark vertical bars on the sides and reddish in the lower fins. It grows to 6 lbs (3 kg), rarely more. The yellow perch, similar but yellower, grows to about 15 in. (40 cm) and weighs up to 2 lbs (1 kg); it is a popular game fish. See also sauger, sea bass, walleye.

Percheron Vpor-cho-.ranN Heavy breed of draft horse that originated in France’s Perche region. The breed probably stems from the medieval Flemish “great horse,” which was modified by Oriental and draft-type blood to produce animals for heavy farm work. Percherons became popu¬ lar in the U.S. in the 1850s and influenced U.S. agriculture more than any other draft breed. They average 16-17 hands (64-68 in. [163-173 cm]) high and weigh 1,900-2,100 lb (860-950 kg). Common colours are black and gray. Agile and energetic for their size, they have a mild disposition.

percussion instrument A musical instrument that is struck (or some¬ times shaken or scraped) to produce sound. This category includes instru¬ ments whose own hard substance is made to vibrate (idiophones) and instruments that include a tight membrane that vibrates (membrano- phones). Percussion instruments may produce tones of definite or indefi¬ nite pitch. Their primary function is often rhythmic, but many are used as melody instruments. They include the bell, carillon, cymbal, drum, dul¬ cimer, GAMELAN, GLOCKENSPIEL, MARIMBA, PIANO, STEEL DRUM, TABLA, TAMBOURINE, TIMPANI, VIBRAPHONE, and XYLOPHONE.

Percy, John (b. March 23, 1817, Nottingham, Nottinghamshire, Eng.—d. June 19, 1889, London) British metallurgist. He turned to met¬ allurgy after obtaining a medical degree, and in 1848 he devised a pro¬ cess for extracting silver from its ores, which soon came into widespread use. He improved the Bessemer process for making steel, and he was the first to survey British iron ores. At London’s Metropolitan School of Sci¬ ences, he trained a generation of metallurgists. His multi volume Treatise on Metallurgy (1861-80), though unfinished, quickly attained classic sta¬ tus.

Percy, Walker (b. May 28, 1916, Birmingham, Ala., U.S.—d. May 10, 1990, Covington, La.) U.S. novelist. He was orphaned in late child¬ hood and was raised by a cousin in Mississippi. While working as a pathologist he contracted tuberculosis; during his recuperation he decided on a writing career and converted to Roman Catholicism. His first and best-known novel, The Moviegoer (1961), introduced his concept of mal¬ aise, a sense of spiritual emptiness characteristic of the rootless modern world. His other works, often about the search for faith and love in a New South transformed by industry and technology, include Love in the Ruins (1971), The Second Coming (1980), and The Thanatos Syndrome (1987).

Samuel Pepys, oil painting by John Hayls, 1666; in the National Portrait Gallery, London.

COURTESY OF THE NATIONAL PORTRAIT GALLERY, LONDON

© 2006 Encyclopaedia Britannica, Inc.

1472 I peregrine falcon ► performance art

peregrine falcon Vper-o-groM or duck hawk Falcon species (Falco peregrinus) found worldwide but rare today because of bioaccumu¬ lation of pesticides. Peregrines are 13-19 in. (33-48 cm) long and gray above, with black-barred whitish underparts. They fly high and dive at tremendous speed (up to 175 mph, or 280 kph—the greatest speeds attained by any bird), striking with clenched talons and killing by impact. They usually nest in a scrape on a high cliff ledge near water, where bird prey is plentiful. Breeding programs have reintroduced the spe¬ cies into the wild and introduced it into urban areas, where it finds a cliff¬ like habitat among skyscrapers and preys chiefly on the rock dove (see pigeon). Despite the programs’ suc¬ cess, the species remains vulnerable.

Pereira \p9-'ra-ra\ City (pop., 1999 est.: 381,725), west-central Colom¬ bia. It is in the western foothills of the Cordillera Central of the Andes Mountains above the Cauca River valley. Founded in 1863 on the former site of Cartago, it is a centre for coffee production and cattle raising and has some light manufacturing.

Perelman Vper-ol-monV S(idney) J(oseph) (b. Feb. 1,1904, Brook¬ lyn, N.Y., U.S.—d. Oct. 17, 1979, New York, N.Y.) U.S. humorist. Per¬ elman attended Brown University and soon began writing screenplays for early Marx Brothers films such as Monkey Business (1931) and Horse Feathers (1932). A master of wordplay, he regularly contributed essays to The New Yorker, many were collected in books such as Westward Ha! (1948) and The Road to Miltown (1957). He collaborated with Kurt Weill on the musical One Touch of Venus (1943). His later screenplays include Around the World in 80 Days (1956, Academy Award).

perennial Any plant that persists for several years, usually with new herbaceous growth from a part that survives from season to season. Trees and shrubs are perennial, as are some herbaceous flowers and vegetative ground covers. Perennials have only a limited flowering period, but with maintenance throughout the growing season, they provide a leafy pres¬ ence and shape to the garden landscape. Popular flowering perennials include bellflowers, chrysanthemums, columbines, lockspurs, hollyhocks, phlox, pinks, poppies, and primroses. See also annual, biennial.

Peres \'per-es\, Shimon orig. Shimon Perski (b. Aug. 16, 1923, Wotozyn, Pol.) Polish-born Israeli statesman. He immigrated to Palestine _ with his family in 1934 and joined the Haganah organization in 1947. After

Israel achieved independence, he held a number of positions in the defense jm establishment (1948-65). In 1968 he helped establish the Israel Labour

M Party. The indecisive 1984 election led to a power-sharing arrangement

with Likud candidate Yitzhak Shamir, the two men alternating as prime min¬ ister. During Peres’s tenure (1984-86), Israel withdrew from most of Leba- 9 non. He was foreign minister under Yitzhak Rabin (1992-95); Peres, Rabin,

and Palestinian leader Yasir ‘Arafat shared the 1994 Nobel Prize for Peace. Peres became prime minister again upon Rabin’s assassination in 1995 but was narrowly defeated in his bid for reelection by Likud leader Benjamin Netanyahu in 1996. Although Peres declined to seek reelection as leader of the Labour Party in 1997, he later served as foreign minister (2001-02), deputy prime minister (2001-02), and vice prime minister (2005) in the national unity government led by Likud’s Ariel Sharon. In 2003 Peres resumed the chair of the Labour Party but was unexpectedly defeated in the party’s leadership election in 2005. He subsequently left the Labour Party.

perestroika \,per-3-'str6i-k9\ Russian "restructuring" Program instituted in the Soviet Union by Mikhail Gorbachev in the mid-1980s to restructure Soviet political and economic policy. Gorbachev proposed reducing the direct involvement of the Communist Party leadership in the country’s governance and increasing the local governments’ authority. Seeking to bring the Soviet Union up to economic par with capitalist countries such as Germany, Japan, and the U.S., he decentralized eco¬ nomic controls and encouraged enterprises to become self-financing. The economic bureaucracy, fearing loss of its power and privileges, obstructed much of his program.

Peretz \'per-ets\, l(saac) L(eib) or Yitskhok Leybush Perets (b.

May 18, 1852, or May 20, 1851, Zamosc, Pol., Russian Empire—d. April 3, 1915, Warsaw) Polish writer. Peretz wrote prolifically, mostly in Yid¬ dish, bringing to the language both a new expressive force and modern¬ izing influences from western European art and literature. His tales of Hasidic lore (e.g., the Silent Souls series) are elegiac meditations on tra¬ ditional values that draw material from the lives of impoverished eastern European Jews. Among his works are story collections, including Folk¬ tales (1908), the drama The Golden Chain (1909), and articles on many subjects to encourage Jews toward wider secular knowledge.

Perez (Rodriguez), Carlos (Andres) (b. Oct. 27, 1922, Rubio, Venez.) President of Venezuela (1974-79, 1989-93). He began his politi¬ cal career at age 18. A founder of Democratic Action, he was elected president in 1973 with the support of the liberal Romulo Betancourt. He nationalized the oil industry while retaining experienced foreign person¬ nel to ensure efficiency, slowed production to conserve resources, stimu¬ lated small business and agriculture, and channeled petroleum income into hydroelectric projects, education programs, and steel mills. Reelected in 1989, Perez promoted free-market economic reforms. After surviving two attempted coups, he was imprisoned in 1993 on charges of embezzlement and misuse of public funds.

Perez de Cuellar \'per-es-tha-'kwa-yar\, Javier (b. Jan. 19, 1920, Lima, Peru) Fifth secretary-general of the United Nations (1982-91). He joined the Peruvian foreign ministry in 1940 and its foreign service in 1944, serving in France, Britain, Bolivia, and Brazil. After serving as ambassador to Switzerland and as Peru’s first ambassador to the Soviet Union, he was appointed the country’s ambassador to the UN, a post he held until he was appointed secretary-general. As secretary-general he advocated the use of the United Nations Security Council for keeping the peace and as a forum for negotiation. In his second term, he negotiated the cease-fire that ended the Iran-Iraq War (1988). Perez de Cuellar later served as prime minister of Peru (2000-01).

Perez Galdos \ , pa-rath-gal-'dos\, Benito (b. May 10, 1843, Las Pal¬ mas, Canary Islands, Spain—d. Jan. 4, 1920, Madrid) Spanish novelist. In the 1870s he began a cycle of 46 short historical novels, Episodios nacionales (1873-1912), that earned him comparison with Honore de Balzac and Charles Dickens. Some of his finest works chronicle contem¬ porary Spain, including The Disinherited Lady (1881) and his master¬ piece, Fortunata y Jacinta (1886-87), a study of two unhappily married women. His earlier works show a reforming zeal and anticlericalism, but after the 1880s he displayed greater sympathy for Spain and its idiosyn¬ crasies, as in Nazarin (1895), Compassion (1897), and a series featuring the character Torquemada. He also wrote plays, some very popular but of less artistic value. He was regarded as Spain’s greatest novelist since Miguel de Cervantes.

Perez Jimenez Vper-ez-he-'men-ezX, Marcos (b. April 25, 1914, Michelena, Venez.—d. Sept. 20, 2001, Madrid, Spain) Soldier and presi¬ dent of Venezuela (1953-58). He graduated from the Venezuelan Military Academy and in 1945 and 1948 participated in coups d’etat. Appointed to the presidency by the military and elected in 1953 by the constituent assembly, which he controlled, he embarked on a program of vast public works. He and his associates received commissions on every project. His regime was marked by extravagance, corruption, police oppression, unemployment, and high inflation. He was forced out of office in 1958 and later jailed for embezzling government funds. His repeated attempts to reenter political life were thwarted.

perfect gas or ideal gas Gas whose physical behaviour conforms to the general gas law, which states that for a given quantity of gas, the product of the volume V and pressure P is proportional to the absolute temperature T, or PV = kT, where k is a constant. A perfect gas is assumed to consist of a large number of molecules in random motion, which obey Newton's laws of motion. Their volume is assumed to be negligibly small, and no forces are presumed to act on the molecules except during momen¬ tary collisions. Though no gas has these properties, real gases at suffi¬ ciently high temperatures and low pressures can be described this way.

performance art Art form that arose in Europe and the U.S. in the 1960s. The term describes an art that is live but operates outside the tra¬ ditional conventions of theatre or music. Early examples represented a challenge to orthodox art forms and cultural norms by creating an ephem¬ eral art experience that could not be captured or purchased. By the 1970s performance art was used as a general term to describe a multitude of

Peregrine falcon (Falco peregrinus).

KENNETH W. FINK-ROOT RESOURCES

© 2006 Encyclopaedia Britannica, Inc.

perfume ► periodic table I 1473

activities, including happenings, body art, actions, events, and non-matrix theatre. Prominent performance artists have included Joseph Beuys, John Cage, Dennis Oppenheim, Yoko Ono, Nam June Paik, Meredith Monk, and Laurie Anderson.

perfume Fluid preparation used for scenting, composed of natural essences or synthetics and a fixative. Perfumes are concocted by the art¬ ful blending of certain fragrant substances in appropriate proportions. The art of perfumery was apparently known to the ancient Chinese, Hindus, Egyptians, Israelites, Carthaginians, Arabs, Greeks, and Romans; refer¬ ences to perfumes are found in the Bible. Raw materials used in perfum¬ ery include natural products, of plant or animal origin, and synthetic materials. Fine perfumes may be blends of more than 100 ingredients.

perfume bottle Vessel made to hold scent. The earliest example is Egyptian and dates to c. 1000 bc. The fashion for perfume later spread to Greece, where terra-cotta and glass containers were made in a variety of shapes such as animals and human heads. Romans made perfume bottles out of molded and blown glass. The spread of Christianity marked a decline in perfume production, as well as of glassmaking. The revival of perfume making in France in the 12th century and the popularity of Vene¬ tian gass in the 13th century revived the production of perfume bottles.

Pergamum Vpor-go-momX Greek Pergamon Vpsr-gs-mosV Ancient Greek city, western Anatolia, near the modern town of Bergama, Turkey. It existed from at least the 5th century bc but became important in the Helle¬ nistic period when it was the residence of the Attalid dynasty and reached its height (263-133 bc). Then it was bequeathed to Rome. After the fall of Rome, it was ruled by the Byzantine Empire until it passed into Ottoman hands in the early 14th century ad. It is one of the most outstanding examples of city planning in antiquity, and its library was excelled only by that at Alexandria, Egypt. Excavations begun in 1878 by the German archaeologists unearthed many artistic treasures, including the great altar of Zeus, which are now housed in Berlin’s Pergamon Museum.

pergola Vpsr-gs-lsN Garden walk or terrace typically formed by two rows of columns or posts roofed with an open framework of beams and cross rafters over which plants are trained. Its purpose is to provide a foun¬ dation on which climbing plants can be viewed and to give shade. Known in ancient Egypt, pergolas were a common feature of early Renaissance gardens in Italy and subsequently throughout Europe. They had a marked revival during the Arts and Crafts Movement in Britain. See also arbor.

Pergolesi V.par-go-'la-zeV Giovanni Battista (b. Jan. 4, 1710, Jesi, Italy—d. March 16, 1736, Pozzuoli) Italian composer. In 1732 he was appointed chapel master to a Neapolitan prince. His comic opera Lofrate ’nnamorato (1732) was followed in 1733 by an opera seria, which had a comic intermezzo that became his best-known work, La serva padrona. His health failing, he moved into a Franciscan monastery (1736), where he wrote his famous Stabat Mater and Salve Regina before dying at age 26. Traveling opera troupes took up La serva padrona, and in 1752 the success of a Paris production set off the controversy known as the guerre des bouf- fons (“war of the buffoons”), with musical forgers vying to produce spu¬ rious works of Pergolesi, leaving some uncertainty about the authenticity of works attributed to him.

Periander \,per-e-'an-d9r\ (d. c.

587 bc) Second tyrant of Corinth (c.

627-587). He was the son of Cypse- lus, founder of the Cypselid dynasty.

One of the most violent of the early Greek tyrants, he killed his wife and avenged the death of his son in Cor- cyra by sending 300 Corcyran boys to be castrated (they managed to escape). He treated the nobility harshly but built a strong, prosperous Corinthian economy. His extensive building program included construc¬ tion of the Diolkos, a portage used to transport ships across the Isthmus of Corinth.

Pericles \'per-9-,klez\ (b. c. 495,

Athens—d. 429 bc, Athens) Athenian general and statesman largely responsible for the full development

of Athenian democracy and the Athe¬ nian empire. Related to the influential Alcmaeonid family, he was elected to power sometime after 461, and he quickly helped adopt essential demo¬ cratic reforms. He asserted Athenian control over the Delian League and used the league’s treasury to rebuild the Acropolis, which had been sacked by the Persians. His influential con¬ sort Aspasia bore him a son, who was legitimated when his legitimate sons died. In 447—446 Athens lost Megara, giving Sparta direct access to Attica.

Though Athens and Sparta agreed on a Thirty Years’ Peace (446-445), Per¬ icles had the Long Walls from Athens to the port at Piraeus strengthened for protection. When war broke out in 431, he relied on the navy to keep the city supplied. Attica’s population was brought inside the Long Walls, leaving the countryside open to Spartan pillaging. When plague broke out, killing one-fourth of the population, he was deposed and fined. He was reelected, but he too died of the plague. His great funeral oration (c. 430) remains one of the greatest defenses of democracy, and his era is remem¬ bered as the Golden Age of Athens.

peridot \'per-9-.dat, 'per-9-,do\ or precious olivine Va-l9-,ven\ Gem- quality, transparent green olivine. Very large crystals are found in Myan¬ mar; peridots from the U.S. are seldom larger than two carats. Yellow- green peridot has been called chrysolite (Greek for “golden stone”); this term, used for various unrelated minerals, is now less common for the gemstone.

peridotite Vps-'ri-ds-.tltV Coarse-grained, heavy, igneous rock that con¬ tains at least 10% olivine, other iron- and magnesium-rich minerals (gen¬ erally pyroxenes), and not more than 10% feldspar. Peridotite is the ultimate source of all chromium ore and naturally occurring diamonds, and of nearly all chrysotile asbestos. Nearly all peridotite is more or less altered to ser¬ pentine; in warm, humid climates peridotite and serpentine have weath¬ ered to soils and related deposits that, though now worked on a relatively small scale, are potential sources of iron, nickel, cobalt, and chromium.

Perier \par-'ya\, Casimir (-Pierre) (b. Oct. 21, 1777, Grenoble, France—d. May 16, 1832, Paris) French statesman. Son of a financier, he cofounded a bank in 1801 and by 1814 was a leading banker in Paris. He was elected to the French Chamber of Deputies (1817), where he opposed Charles X. After the July Revolution of 1830 made Louis- Philippe king, Perier became premier (1831) and quickly restored civic order in France. Active in foreign affairs, he sent an army to defend Belgium against the Dutch (1831) and ordered the occupation of Ancona to check Austrian predomi¬ nance in the Papal States (1832). His authoritarian approach brought attacks from both left and right and sometimes alienated the king.

Perigord \,pa-re-'g6r\ Historic and cultural region, southern France. The counts of Perigord played a part in the troubled affairs of Aquitaine, and control of Perigord was disputed by the French and the English from 1259. The area was transferred to the house of Albret in 1470. After it was inherited by the crown of Navarra, Henry IV united it with the French crown in 1607.

period In geology, the basic unit of the geologic time scale. During these spans of time, specific systems of rocks were formed. Originally, the method for defining the sequence of periods was relative; it was based on stratigraphy and paleontology. Carbon- 14 dating and similar methods are now used to determine absolute ages for various periods.

periodic motion Motion that is repeated in equal intervals of time. The time of each interval is the period. Examples of periodic motion include a rocking chair, a bouncing ball, a vibrating guitar string, a swing¬ ing pendulum, and a water wave. See also simple harmonic motion.

periodic table Organized array of all the chemical elements in approxi¬ mately increasing order of their atomic weight. The elements show a peri¬ odic recurrence of certain properties, first discovered in 1869 by Dmitry I. Mendeleyev. Those in the same column (group) of the table as usually

Periander, marble bust in the Vatican Museum, Rome

THE MANSELL COLLECTION

Pericles, detail of a marble herm; in the Vatican Museum

ANDERSON-AUNARI FROM ART RESOURCE/EB INC.

© 2006 Encyclopaedia Britannica, Inc.

1474 I periodical ► Perl

arranged have similar properties. In the 20th century, when the structure of atoms was understood, the table was seen to precisely reflect increas¬ ing order of atomic number. Members of the same group in the table have the same number of electrons in the outermost shells of their atoms and form bonds of the same type, usually with the same valence; the noble GAS es, with full outer shells, generally do not form bonds. The periodic table has thus greatly deepened understanding of bonding and chemical behaviour. It also allowed the prediction of new elements, many of which were later discovered or synthesized. For an illustration of the periodic table, see chemical element.

periodical Publication whose issues appear at fixed or regular inter¬ vals. Periodicals generally are considered to include newspapers, which usually have large, unfastened pages and contents with considerable immediacy; and magazines, or journals, which have smaller pages, are usually fastened or bound, and often have more specialized, less time- dependent contents.

periodontitis V.per-e-o-.dan-'tl-tosX Inflammation of soft tissues around the teeth (see tooth). Poor dental hygiene leads to deposition of bacterial plaque on the teeth below the gum line, irritating and eroding nearby tis¬ sues. If it is not treated, the gum margin recedes, exposing the roots of the teeth. The process eventually involves the bone anchoring the teeth, which loosen and may fall out. Removal of all plaque deposits and affected soft tissues can arrest but not reverse bone deterioration.

periosteum V.per-e-'as-te-omN Dense membrane over bones. The outer layer contains nerve fibres and many blood vessels, which supply cells in the bone. The bone-producing cells of the inner layer are most prominent in fetal life and early childhood, when bone formation is at its peak. In adulthood they are less active but vital to continuous bone remodeling. When bone is injured, they multiply profusely to produce new bone.

periscope Optical instrument (see optics) used in land and sea warfare, submarine navigation, and elsewhere to enable an observer to see the sur¬ roundings while remaining under cover, behind armour, or submerged. A periscope includes two mirrors or reflecting prisms to change the direction of the light coming from the scene observed: the first deflects it down through a vertical tube, the second diverts it horizontally so that the scene can be viewed conveniently.

peristalsis \,per-9-'st6l-s9s\ Progressive wavelike muscle contractions in the esophagus, stomach, and intestines, and sometimes in the ureters and other hollow tubes. The waves can be short, local reflexes or long, con¬ tinuous contractions along the length of the organ. In the esophagus, peri¬ staltic waves push food into the stomach. In the stomach, they help mix stomach contents and propel food to the small intestine, where they expose food to the intestinal wall for absorption and move it forward. Peristalsis in the large intestine pushes waste toward the anal canal and is important in removing gas and dislodging potential bacterial colonies.

I peritonitis \,per-3-t 3 n-'i-t3s\ Inflammation of the peritoneum (see abdomi-

m nal cavity), with pus accumulating between the parietal and the visceral

peritoneum, abdominal pain and distension, vomiting, and fever. It may be acute or chronic, local or generalized. Acute peritonitis usually results m from inflammation elsewhere (e.g., by spread of bacterial infection). Pri¬ ll mary peritonitis often comes from a perforated gastrointestinal tract, as

with rupture in appendicitis. Control of the source problem may be fol¬ lowed by remission, adhesions, or abscesses (much rarer since the devel¬ opment of antibiotics).

periwinkle In botany, any of various plants of the genus Vinca of the dogbane family. The lesser periwinkle (U minor), which has small lilac- blue flowers, is a dependable, trailing, evergreen perennial that is native to Europe and has become widespread over much of eastern North America. The greater periwinkle (U major), with larger leaves and larger purplish-blue flowers, is native to continental Europe and has become naturalized in England. Alkaloids derived from the periwinkle plant have had some success in inhibiting cancer growth.

periwinkle In zoology, any of some 80 species (family Littorinidae) of widely distributed, chiefly herbivorous shore SNAILS. Periwinkles are usu¬ ally found on rocks, stones, or pilings between high- and low-tide marks. The common periwinkle ( Littorina littorea), the largest northern species, may grow to 1.5 in. (4 cm) long. It is usually dark gray and has a solid spiral shell. Introduced into North America c. 1857, it is now common on Atlantic coasts. All periwinkle species are a favourite food of many shore- birds. See photograph above.

Periyar \,per-i-'yar\ River River, central Kerala state, southwestern India. It is 140 mi (225 km) long and rises in the Western Ghats range near the border with Tamil Nadu state. It flows north to Periyar Lake, an arti¬ ficial reservoir created by damming the river. A tunnel carries water from the lake eastward through the moun¬ tains to the Vaigai River, where it is used for irrigation. From the lake it flows northwest and empties into the Arabian Sea.

perjury In law, act or crime of knowingly making a false statement while under oath. The statement must be material to the issue of inquiry. Perjuries that have the effect of obstructing the adjudication of a case may be given increased punishment for that reason. A person who makes a false statement and later corrects it is usually not considered to have committed perjury.

Perkins, Anthony (b. April 4, 1932, New York, N.Y., U.S.—d. Sept. 12, 1992, Hollywood, Calif.) U.S. film actor. He was the son of the actor Osgood Perkins, and he studied at Columbia University. After making his screen debut in The Actress (1953), he appeared in films such as Friendly Persuasion (1956) and Fear Strikes Out (1957), but he was best known as the murderous motel owner Norman Bates in Alfred Hitchcock’s Psy¬ cho (1960). He later appeared in several films in Europe, including The Trial (1963), The Champagne Murders (1967), and Ten Days’ Wonder (1972), and in U.S. films such as Pretty Poison (1968), Catch-22 (1970), and WUSA (1970). He reprised his role as Norman Bates in three sequels (1983, 1986, and 1990).

Perkins, Frances orig. Fannie Coralie Perkins (b. April 10, 1882, Boston, Mass., U.S.—d. May 14,1965, New York, N.Y.) U.S. public official. She became a social worker in New York City and a leader in orga¬ nizations aiming to improve working conditions for women. From 1929 to 1933 she served as state industrial commissioner under New York Gov. Franklin D. Roosevelt. As president, Roosevelt appointed her U.S. secretary of labor; she thereby became the first woman to hold a U.S. cabinet post. In her long term of office (1933—45) she advocated reforms such as a minimum wage, a maximum workweek, and unemployment compensation; she also helped draft the Social Security Act and supervised the Fair Labor Standards Act (1938). She was later a U.S. Civil Service commissioner (1945-53).

Perkins, Jacob (b. July 9, 1766, Newburyport, Mass., U.S.—d. July 30, 1849, London, Eng.) U.S. inventor. He built a machine to cut and head nails in one operation c. 1790. He developed a method of engraving paper money that made counterfeiting difficult; lack of interest in the U.S. led him to set up a bank-note factory in England (1819). He experimented with high-pressure steam boilers, built a horizontal steam engine (1827), designed an improved paddle wheel (1829), and invented a means for the free circulation of water in boilers (1831) that led to the design of mod¬ ern water-tube boilers.

Perkins, Maxwell (Evarts) (b. Sept. 20, 1884, New York, N.Y., U.S.—d. June 17, 1947, Stamford, Conn.) U.S. editor. He worked as a reporter for The New York Times before joining the publishing firm of Charles Scribner’s Sons, of which he later became editorial director and vice president. He is best known for the intensive editorial work that shaped Thomas Wolfe’s sprawling manuscripts into publishable form, but he also assisted the early careers of F. Scott Fitzgerald, Ernest Hemingway, Ring Lardner, Erskine Caldwell, Edmund Wilson, and Alan Paton.

Perl in full Practical Extraction and Reporting Language.

High-level computer programming language, the most popular language for writing CGI scripts and the premier scripting (or interpreted) language of the World Wide Web. Since it has roots in UNIX, its syntax is similar to C and it includes several UNIX utilities. Because of its excellent text¬ processing capability, it is widely used by system administrators (for writ¬ ing administrative tasks) and is especially suited for developing prototype versions of programs. Because it is an interpreted language, its programs are highly portable across different operating systems. Originally devel¬ oped by Larry Wall at NASA’s Jet Propulsion Laboratory in 1986, it has since been improved by hundreds of volunteer developers. Like Linux, it can be obtained free of charge.

Periwinkles ( Littorina)

JANE BURTON-BRUCE COLEMAN LTD.

© 2006 Encyclopaedia Britannica, Inc.

perlite ► Perpignan I 1475

perlite or pearlstone Natural glass with concentric cracks such that the rock breaks into small, pearl-like bodies. It is formed by the rapid cooling of viscous lava or magma. Perlite is porous and has a waxy to pearly lustre and is commonly gray or greenish but may be brown, blue, or red. Since c. 1950, large deposits have been worked in New Mexico, Nevada, California, and other western states. Heat-treated perlite is a sub¬ stitute for sand in lightweight wall plaster and concrete aggregate. Perlite is used for heat and sound insulation, lightweight ceramic products, and filters.

Perlman, Itzhak (b. Aug. 31, 1945, Tel Aviv, Palestine) Israeli-born U.S. violinist. Despite a bout with polio at age four that left his legs para¬ lyzed, he was a prodigy, and he made his U.S. television debut at age 13. He studied with Ivan Galamian and Dorothy DeLay at Juilliard. Recog¬ nition of his gifts led to a highly successful career as orchestral soloist and chamber-music player, with scores of recordings. Blessed with a popular touch, he appeared on television, played jazz and klezmer music, and involved himself in educating young musicians.

permafrost Perennially frozen earth, with a temperature below 32 °F (0 °C) continuously for two years or more. Permafrost is estimated to underlie 20% of the Earth’s land surface and reaches depths of 5,000 ft (1,500 m) in northern Siberia. It occurs in 85% of Alaska, more than half of Russia and Canada, and probably all of Antarctica. Permafrost has a significant effect on plant and animal life, and it presents special prob¬ lems in engineering projects. All land use in permafrost environments must take into account the terrain’s special sensitivity; if the delicate natural balance is not maintained, extensive degradation and ecological damage may result.

permeability, magnetic See magnetic permeability

Permian Period Interval of geologic time, 290-248 million years ago. The last of the six periods of the Paleozoic Era, it follows the Carbonif¬ erous Period. During the Permian, the continents joined to form a single supercontinent, Pangea. Hot, dry conditions prevailed almost everywhere, and deserts were widespread. Life evolved as a continuation of established lines. Marine invertebrates evolved into several lineages. Marine and freshwater fish and amphibians thrived. Reptiles evolved into three dis¬ tinct groups: the cotylosaurs, the pelycosaurs, and the therapsids. Land plants evolved from ferns and seed ferns to conifers and adapted to drier and well-drained land conditions. Toward the close of the Permian, many forms of life suffered mass extinction, whose causes are unknown.

permutations and combinations Number of ways a subset of objects can be selected from a given set of objects. In a permutation, order is important; in a combination, it is not. Thus, there are six permutations of the letters A, B, C selected two at a time (AB, AC, BC, BA, CA, CB) yet only three combinations (AB, AC, BC). The number of permutations of r objects chosen from a set of n objects, expressed in factorial nota¬ tion, is n\ -j- (n - r)! The number of combinations is n\ 4 [r(n - r)!]. The (r + l)st coefficient in the binomial expansion of (x + y) n coincides with the combination of n objects chosen r at a time (see binomial theorem). Probability theory evolved from the study of gambling, including figuring out combinations of playing cards or permutations of win-place-show possibilities in a horse race, and such counting methods played an impor¬ tant role in its development in the 17th century.

Pernambuco See Recife

pernicious anemia Slow-developing disease in which vitamin B 12 (see vitamin B complex) deficiency impairs red-blood-cell production. It can result from a diet lacking in vitamin B 12 or when intrinsic factor, a sub¬ stance needed for intestinal absorption of B 12 , either is not produced by stomach cells or cannot bind to the vitamin. It causes weakness, waxy pallor, shiny tongue, and stomach, intestinal, and neurological problems. Its slow development can allow anemia to become very severe by the time of diagnosis. Monthly B 12 injections into muscle soon reverses the ane¬ mia, but the injections must be continued for life.

Peron \pa-'ron\, Eva (Duarte de) known as Evita orig. Maria Eva Duarte (b. May 7, 1919, Los Toldos, Arg.—d. July 26, 1952, Buenos Aires) Second wife of Argentine president Juan Peron and a powerful though unofficial political leader. Born into poverty, she was an actress when she married Peron. She was instrumental in the success of his first presidential campaign and won the adulation of the masses. Evita acted as de facto minister of health and labour, awarding generous wage increases to workers. With “voluntary” contributions from businesses.

labour unions, and the elite, she established thousands of hospitals, schools, and orphanages. After her death from cancer at age 33, her grief- stricken working-class followers sought to have her canonized.

Peron, Isabel (Martinez de) orig. Maria Estela Martinez Cartas (b. Feb. 4, 1931, La Rioja, Arg.) Third wife of Juan Peron and president of Argentina (1974-76). Born into a lower-middle-class family, she was a dancer when she met Peron in 1955 or 1956. They married during his exile in 1961, and she became his running mate in the 1973 presidential election. She succeeded him when he died in 1974, inherit¬ ing problems of inflation and political violence, which she tried— ineffectively—to solve by printing money and imposing a state of siege. She was deposed in 1976; after five years of house arrest, she was con¬ victed of corruption but permitted to go into exile in Spain.

Peron, Juan (Domingo) (b. Oct. 8, 1895, Buenos Aires province, Arg.—d. July 1, 1974, Buenos Aires) President of Argentina (1946-55, 1973-74). After attending military school, he served in the 1930s in Italy, where he observed the successes of the Fascists. In 1943 he helped over¬ throw Argentina’s ineffective civilian government. As secretary of labour and social welfare, he built a loyal following among industrial workers, who helped elect him president in 1946. Peron’s political views drew on both the far left and the far right: while he showered workers with much- needed benefits, he restricted civil liberties severely. The charisma of his second wife, Eva Peron, greatly increased the regime’s standing with the populace. He was reelected in 1951, but a disastrous economic decline and increasing disaffection among many elements of Argentine society led to his overthrow in 1955 by democratically inspired military officers. He lived in exile in Spain for two decades but continued to influence Argentine affairs. When the Peronist party was made legal, he was reelected president in absentia; he died less than a year after returning to Argentina and assuming the presidency. See also Isabel Peron.

Peronist \p9-'ro-nist\ Member of Argentina’s Justicialist Nationalist Movement, a supporter of Juan Peron, or an adherent of his populist and nationalist policies. Peron’s poorly defined political philosophy embraced elements of both left- and right-wing ideology, combining a commitment to the redistribution of wealth with authoritarian nationalism and disre¬ gard for civil rights. After his death in 1974, the Justicialist movement was weakened by factionalism, but it continued to play an important role in Argentine politics and had adherents elsewhere. See also Carlos Menem.

Perot \p3-'ro\, H(enry) Ross (b. June 27, 1930, Texarkana, Texas, U.S.) U.S. businessman. After graduating from the U.S. Naval Academy, he served in the navy (1953-57). He worked for IBM from 1957 to 1962, when he formed his own company, Electronic Data Systems; he sold it in 1984 to General Motors for $2.5 billion. In 1992 he became an inde¬ pendent candidate for U.S. president. Appealing to voters dissatisfied with traditional party politics, he won 19% of the popular vote, the best third- party presidential showing since 1912. He ran again in 1996 but received only 8% of the vote. His Reform Party, which he founded in 1995, gradu¬ ally established its autonomy from him.

peroxide Any of a class of chemical compounds in which two oxygen atoms are linked by a single covalent bond. Several organic (see organic compound) and inorganic (see inorganic compound) peroxides are useful as bleaching and oxidizing agents (see oxidation-reduction), as initiators of polymerization reactions, and in the preparation of hydrogen peroxide (a mild bleach and antiseptic) and other oxygen compounds. The perox¬ ide anion (chemical formula 0 2 - ) is present in peroxides of inorganic compounds.

Perpendicular style Phase of late Gothic architecture in England roughly parallel in time to the French Flamboyant style. The style, con¬ cerned with creating rich visual effects through decoration, was charac¬ terized by a predominance of vertical lines in stone window tracery, enlargement of windows to great proportions, and conversion of the inte¬ rior stories into a single unified vertical expanse. Fan vaults, springing from slender columns or pendants, became popular. The oldest surviving example of the style is probably the choir of Gloucester Cathedral (begun c. 1335). Other major monuments include King’s College Chapel, Cam¬ bridge (1446-1515), and the chapel of Henry VII in Westminster Abbey. In the 16th century, the grafting of Renaissance elements onto the Perpen¬ dicular style resulted in the Tudor style.

Perpignan \,per-pe-'nya n \ City (pop., 1999: 105,115), southern France. Located just north of the Spanish border, Perpignan was founded c. 10th

© 2006 Encyclopaedia Britannica, Inc.

1476 I Perrault ► Pershing

century. It was the capital of Roussillon in the 12th century and of the kingdom of Majorca from 1276 to 1344. The city was heavily fortified during the struggle between France and Spain for the area; it became French in 1659. It is now a market centre for the surrounding agricultural area; its many medieval buildings have made tourism economically important.

Perrault \pe-'ro\, Charles (b. Jan. 12, 1628, Paris, France—d. May 15/16, 1703, Paris) French poet, prose writer, and storyteller. Perrault began to win a literary reputation c. 1660 with light verse and love poetry. He is best remembered for his collection of charming fairy stories writ¬ ten to amuse his children, Contes de ma mere I’oye, or Tales of Mother Goose (1697; see Mother Goose). He spent the rest of his life promoting the study of literature and the arts. A leading member of the Academie Francaise, he was involved in a famous controversy with Nicholas Boileau on the relative merits of ancient and modem literature; his support for the modern was of landmark significance in the revolt against the constraints of prevailing tradition.

Perrot\pe-'ro\ / Jules (-Joseph) (b. Aug. 18, 1810, Lyon, Fr.—d. Aug. 24, 1892, Parame) French dancer and choreographer. After studying with Auguste Vestris, he debuted at the Paris Opera in 1830. He often partnered Marie Taglioni until 1835, when he left the company to tour in Europe. He choreographed several ballets for Carlotta Grisi, probably including the famous solos in Giselle. As dancer and ballet master in London (1842-48) and St. Peters¬ burg (1848-58), he choreographed many important Romantic ballets with an expressive, dramatic style. In his later years he gave classes at the Paris Opera.

Perry, Matthew C(albraith)

(b. April 10, 1794, South Kingston,

R.I., U.S.—d. March 4, 1858, New York, N.Y.) U.S. naval officer. He followed his brother Oliver Perry into the navy and commanded the first U.S. navy steamship, the Fulton (1837-40). He led naval forces in the Mexican War and assisted Winfield Scon at Veracruz. In 1852 Pres. Mill¬ ard Fillmore sent Perry to head a naval expedition to induce Japan to establish diplomatic relations with the U.S. Concluding that the coun¬ try’s centuries-old policy of isolation would be ended only by a show of force, Perry led four ships into the fortified harbour of Uraga (1853) and convinced the Japanese to accept his message. In 1854 he entered Edo (now Tokyo) Bay with nine ships and concluded the first treaty between Japan and the U.S., which granted the U.S. trading privileges and opened the Far East to U.S. influence.

Jules Perrot, engraving after a draw¬ ing.

Perry, Oliver Hazard (b. Aug. 20, 1785, South Kingston, R.I., U.S.—d. Aug. 23, 1819, at sea) U.S. naval officer. The older brother of Matthew Perry, he entered the navy in 1799 and served in the West Indies and the Mediterranean. In 1813 he was ordered to Erie, Pa., to assemble a naval squadron to challenge British control of the Great Lakes in the War of 1812. With 10 small ships, he engaged six British warships in Lake Erie (Sept. 10, 1813). After his flagship was disabled, he was rowed to the Niagara , from which he won the battle by sailing directly into the British line, firing broadside. In reporting the British surrender he wrote, “We have met the enemy and they are ours.”

Perse, Saint-John See Saint-John Perse

Persephone \p3r-'se-fo-ne\ Latin Proserpina In Greek mythology, daughter of Zeus and Demeter. She was gathering flowers when she was seized by Hades, who carried her off to the underworld to make her his wife. On learning of the abduction, Demeter was so distraught that she allowed barrenness and famine to spread over the earth. Zeus commanded Hades to allow Persephone to return to her mother, but because she had

eaten some (or, in some versions, just one) pomegranate seeds in the under¬ world, she had to remain one-third of the year with Hades, spending the other two-thirds with Demeter. This myth accounts for the change of the seasons and the annual cycle of growth and decay.

Persepolis Xpor-'se-po-losN Ancient Persian city, northeast of modern Shiraz, Iran. It was built in a remote and mountainous area during the reign of Darius I, who made it the capital of Persia, replacing Pasar- gadae. In 330 bc Alexander the Great plundered the city and burned the palace of Xerxes I. The city’s ruins cover an extensive area and com¬ prise a number of colossal buildings, including palaces of early Persian kings, a great staircase, an audience hall, and a treasury.

Perseus (b. c. 212—d. c. 165 bc.

Alba Fucens, near Rome) Last king of Macedonia (r. 179-168). Son of Philip V, he fought against Rome (199) and Aetolia (189). He per¬ suaded the king to execute his brother Demetrius. As king he extended his influence in neighbour¬ ing states and tried to gain the trust of the Greek world, but he alarmed Greece by visiting Delphi with an army. Eumenes II of Pergamum informed Rome of Perseus’s allegedly aggressive designs, provoking the Third Macedonian War (171-168). The struggle ended in a final defeat of the Macedonians by the Romans, ending the monarchy, and Perseus spent the rest of his life in captivity.

Perseus In Greek mythology, the slayer of the Gorgon Medusa. He was the son of Zeus and Danae. His grandfather had him thrown into the sea in a chest with his mother as an infant because of a prophecy that Per¬ seus would kill him. Perseus and his mother survived, and as a young man Perseus set out to gain the head of Medusa. On his way home he rescued the Ethiopian princess Andromeda from a sea monster, and she became his wife. When he took his mother back to her native Argos, he threw a discus that accidentally killed his grandfather, thus fulfilling the prophecy.

Pershing X'par-zhiq, 'psr-shiqV, John J(oseph) (b. Sept. 13, 1860, Laclede, Mo., U.S.—d. July 15,

1948, Washington, D.C.) U.S. army officer. He graduated from West Point and served on the western fron¬ tier (1886-98), in the Spanish- American War, in the Philippines (1899-1903, 1906-13), and as com¬ mander of a punitive raid against Pancho Villa (1916). During World War I he was appointed commander in chief of the American Expedition¬ ary Force (AEF). He maintained the AEF as an independent army of two million men and resisted Allied efforts to use U.S. forces as replace¬ ment units for French and British troops. He led the successful assault of the St. Mihiel salient in Septem¬ ber 1918 and helped defeat German forces in the Meuse-Argonne offen¬ sive. He was promoted to general of the armies in 1919 and was army chief of staff from 1921 to 1924. His nickname, “Black Jack,” derived from his service with an African Ameri¬ can regiment early in his career (see buffalo soldier). His memoirs. My Experiences in the World War (1931), won a Pulitzer Prize.

John J. Pershing, 1917.

LIBRARY OF CONGRESS, WASHINGTON, D.C.

Persephone abducted by Hades, marble sculpture by Gian Lorenzo Ber¬ nini, 1621-22; in the Borghese Gal¬ lery, Rome

ANDERSON—AUNARI FROM ART RESOURCE/EB INC.

© 2006 Encyclopaedia Britannica, Inc.

Persia ► personalismo I 1477

Persia Historical name for a region roughly coterminous with modern Iran. The term was used for centuries, chiefly in the West, and originally described a region of southern Iran formerly known as Persis or Parsa. Parsa was the name of an Indo-European nomadic people who migrated into the area c. 1000 bc; the use of the name was gradually extended by the ancient Greeks and other Western peoples to apply to the whole Ira¬ nian plateau. The people of Iran have always called their country Iran, and in 1935 the government requested that the name Iran be used instead of Persia.

Persian cat Breed of stocky, round-headed domestic cat that has a long, silky coat (many colours possible), large round eyes, snub nose, and thick ruff. The breed is often referred to as the longhair.

Persian Gulf Arm of the Arabian Sea. It is about 615 mi (990 km) long and rarely exceeds a depth of 300 ft (90 m). It is connected with the Gulf of Oman and the Arabian Sea through the Strait of Hormuz. It contains the island kingdom of Bahrain and is bordered by Iran, the United Arab Emirates, Oman, Saudi Arabia, Qatar, Kuwait, and Iraq. It has long been a maritime trade route between the Middle East and South Asia; its mod¬ ern economy is dominated by petroleum production.

Persian Gulf War, First or Gulf War (1990-91) International con¬ flict triggered by Iraq’s invasion of Kuwait in August 1990. Though jus¬ tified by Iraqi leader Saddam Hussein on grounds that Kuwait was historically part of Iraq, the invasion was presumed to be motivated by Iraq’s desire to acquire Kuwait’s rich oil fields and expand its power in the region. The United States, fearing Iraq’s broader strategic intentions and acting under UN auspices, eventually formed a broad coalition, which included a number of Arab countries, and began massing troops in north¬ ern Saudi Arabia. When Iraq ignored a UN Security Council deadline for it to withdraw from Kuwait, the coalition began a large-scale air offen¬ sive (Jan. 16-17, 1991). Saddam responded by launching ballistic mis¬ siles against neighbouring coalition states as well as Israel. A ground offensive by the coalition (February 24-28) quickly achieved victory. Estimates of Iraqi military deaths range up to 100,000; coalition forces lost about 300 troops. The war also caused extensive damage to the region’s environment. The Iraqi regime subsequently faced widespread popular uprisings, which it brutally suppressed. A UN trade embargo remained in effect after the end of the conflict, pending Iraq’s compliance with the terms of the armistice. The foremost term was that Iraq destroy its nuclear-, biological-, and chemical-weapons programs. The embargo continued into the 21st century and ceased only after the Second Persian Gulf War.

Persian Gulf War, Second (2003) International conflict that took place between Iraq and a combined force of troops from the United States and Great Britain, with smaller contingents from several other countries. The trade embargo and weapons-inspection process that the UN imposed on Iraq following the First Persian Gulf War (1990-91) had partly fallen into abeyance by 2001. U.S. Pres. George W. Bush argued that the Sep¬ tember 11 attacks on the U.S. in that same year highlighted the threat to U.S. security posed by hostile countries such as Iraq. Encouraged by Bush and British Prime Minister Tony Blair, the UN issued Security Council Resolution 1441 in November 2002, demanding that Iraq readmit weap¬ ons inspectors and comply with all previous resolutions. Although Iraqi did readmit inspectors, Bush and Blair declared in early 2003 (despite objections by many world leaders) that Iraq was continuing to hinder UN inspections and that it still retained proscribed weapons. On March 20, seeking no further UN resolutions, the U.S. and Britain (with token rep¬ resentation from other countries) launched a series of air attacks on Iraq, and a ground invasion followed. Iraqi military and paramilitary forces were rapidly defeated; on April 9 U.S. forces took control of the capital, Baghdad, and British forces completed their occupation of the southern city of AI-Basrah the same day. Within a few more days, all major cities had fallen, and by May 1 major combat operations had been completed. Guerrilla assaults on occupying forces continued thereafter, hindering Iraq’s recovery.

Persian language or Farsi language Iranian language spoken by more than 25 million people in Iran as a first language, and by millions more as a second. Modern Persian is a koine developed from southwest¬ ern dialects in the 7th-9th centuries, after the introduction of Islam brought a massive infusion of loanwords from Arabic. Its standardization and literary cultivation took place in northeastern Persia and Central Asia in the 11 th— 12th centuries. Polities outside Persia itself (e.g., Mughal

India, Ottoman Turkey) have at times been major literary centres. Its sta¬ tus in those countries led to a very strong Persian influence on Urdu and Ottoman Turkish. Other Turkic and Indo-Aryan languages, Caucasian lan¬ guages, and Iranian languages have also borrowed heavily from Persian. It is written in a slightly modified form of the Arabic alphabet.

Persian Wars or Greco-Persian Wars (492-449 bc) Series of wars between Greek states and Persia, particularly two invasions of Greece by Persia (490, 480-479). When Darius I came to power in Persia in 522, the Ionian Greek city-states in Anatolia were under Persian con¬ trol. They rose up unsuccessfully in the Ionian revolt (499-494). The sup¬ port lent by Athens provoked Darius to invade Greece (492). His fleet was destroyed in a storm. In 490 he assembled a huge army on a plain near Athens; his devastating defeat at the Battle of Marathon sent him back to Persia. In 480 the Persians under Xerxes I again invaded Greece, seeking to avenge the defeat. This time all Greece fought together, with Sparta in charge of the army and Athens of the navy. A band of Spartans under Leonidas was overcome at the Battle of Thermopylae, allowing the Persian army to reach Athens, which they sacked (480). When the Per¬ sian navy was soundly defeated at the Battle of Salamis, Xerxes withdrew it to Persia. His army was defeated at the Battle of Plataea in 479 and driven from Greece, and the navy met a similar fate at Mycale on the Anatolian coast. Sporadic fighting went on for 30 more years, during which Athens formed the Delian League to free the Ionians. The Peace of Callias (449) ended the hostilities.

persimmon Either of two trees of family, and their globular, edible fruits. The native American persim¬ mon ( D. virginiana ), a small tree with dark-red to maroon fruits that contain several large, flattened seeds, grows from the Gulf states north to central Pennsylvania and central Illi¬ nois. The Oriental persimmon ( D. kaki), grown extensively in China and Japan, has larger, more astrin¬ gent, yellow to red fruit. Good sources of vitamins A and C, persim¬ mons are eaten fresh or stewed or cooked as jam.

Perski, Shimon See Shimon Peres

personal computer (PC) Microcomputer designed for use by one person at a time. A typical PC assemblage comprises a CPU; internal memory consisting of RAM and ROM; data storage devices (including a hard disc, a floppy disc, or CD-ROM); and input/output devices (including a display screen, keyboard, mouse, and printer). The PC industry began in 1977 when Apple Computer introduced the Apple II. Radio Shack and Commodore Business Machines also introduced PCs that year. IBM entered the PC market in 1981. The IBM PC, with increased memory capacity and backed by IBM’s large sales organization, quickly became the industry standard. Apple’s Macintosh (1984) was particularly useful for desktop publishing. Microsoft Corp. introduced MS Windows (1985), a graphical user interface that gave PCs many of the capabilities of the Macintosh, initially as an overlay of MS-DOS. Windows went on to replace MS-DOS as the dominant operating system for personal comput¬ ers. Uses of PCs multiplied as the machines became more powerful and application software proliferated. Today, PCs are used for word process¬ ing, Internet access, and many other daily tasks.

personal-liberty laws Laws passed by U.S. states in the North to counter the Fugitive Slave Acts. Such states as Indiana (1824) and Con¬ necticut (1828) enacted laws giving escaped slaves the right to jury trials on appeal. Vermont and New York (1840) assured fugitives the right of jury trial and provided them with attorneys. Other states forbade state authorities to capture and return fugitives. After the Compromise of 1850, most Northern states enacted further guarantees of jury trials and punish¬ ment for illegal seizure. These laws were cited by proslavery interests as assaults on states’ rights and as justification for secession.

personal property See real and personal property

personalismo Spanish "personalism" In Latin America, the prac¬ tice of glorifying a leader. It often involves sacrificing the interests of political parties, ideologies, and constitutional government out of loyalty

the genus Diospyros in the ebony

American persimmon (Diospyros vir¬ giniana).

H.R. HUNGERFORD

© 2006 Encyclopaedia Britannica, Inc.

1478 I personality ► Peru

to a leader. Political parties throughout Latin America have often con¬ sisted of the personal following of a single individual, a fact reflected in the popular terms for the partisans. Members of Argentina’s Justicialist National Movement, for example, are called peronistas (Peronists), for its charismatic founder, Argentine president Juan Peron, and the followers of Cuban leader Fidel Castro are fidelistas. See also caudillo.

personality Totality of an individual’s behavioral and emotional char¬ acteristics. Personality embraces a person’s moods, attitudes, opinions, motivations, and style of thinking, perceiving, speaking, and acting. It is part of what makes each individual distinct. Theories of personality have existed in most cultures and throughout most of recorded history. The ancient Greeks used their ideas about physiology to account for differences and similarities in temperament. In the 18th century Immanuel Kant, Charles- Louis Montesquieu, and Giambattista Vico proposed ways of understanding individual and group differences; in the early 20th century Ernst Kretschmer and the psychoanalysts Sigmund Freud, Alfred Adler, and Carl Jung offered competing personality theories. Freud’s model rested on the power of psy- chosexual drives as mediated by the structural components of the ID, EGO, and superego and the interplay of conscious and unconscious motives. Par¬ ticularly important was the array of defense mechanisms an individual employed. Jung, like Freud, emphasized unconscious motives but de-emphasized sexuality and advanced a typal theory that classified people as introverts and extraverts; he further claimed that an individual personal¬ ity was a persona (i.e., social facade) drawn from the “collective uncon¬ scious,” a pool of inherited memories. Later theories by Erik H. Erikson, Gordon W. Allport, and Carl R. Rogers were also influential. Contempo¬ rary personality studies tend to be empirical (based on the administration of projective tests or personality inventories) and less theoretically sweeping and tend to emphasize personal identity and development. Personality traits are usually seen as the product of both genetic predisposition and experience. See also personality disorder; psychological testing.

personality disorder Mental disorder that is marked by deeply ingrained and lasting patterns of inflexible, maladaptive, or antisocial behaviour to the degree that an individual’s social or occupational func¬ tioning is impaired. Rather than being illnesses, personality disorders are enduring and pervasive features of the personality that deviate markedly from the cultural norm. They include the dependent, histrionic, narcissis¬ tic, obsessive-compulsive, antisocial, avoidant, borderline (unstable), paranoid, and schizoid types. The causes appear to be both hereditary and environmental. The most effective treatment combines behavioral and psychotherapeutic therapies (see behaviour therapy; psychotherapy).

personnel administration See industrial relations

perspective Depiction of three-dimensional objects and spatial rela¬ tionships on a two-dimensional plane. In Western art, illusions of volume and space are generally created by use of the linear perspective system, based on the observation that objects appear to shrink and parallel lines to converge at an infinitely distant vanishing point as they recede in space from the viewer. The vanishing point may have been known to the Greeks and Romans but had been lost until Filippo Brunelleschi rediscovered the principles of linear or “mathematical” perspective early in the 15th cen¬ tury. Linear perspective dominated Western painting until the late 19th century, when Paul Cezanne flattened the conventional picture plane. The Cubists and other 20th-century painters abandoned depiction of three- dimensional space altogether. See also aerial perspective.

Perspex See Lucite

perspiration Fluid given off by the skin as vapour by simple evapo¬ ration or as sweat actively secreted from sweat glands to evaporate and cool the body. When the body temperature rises, the sympathetic nervous system stimulates eccrine sweat glands to secrete water to the skin sur¬ face, where it cools the body by evaporation. Human eccrine sweat is essentially a dilute solution of sodium chloride with trace amounts of other plasma electrolytes. In extreme conditions, human beings may excrete several litres of such sweat in an hour.

Perth City (pop., 2004 est.: 1,457,639), capital of Western Australia state, Australia. Located on the Swan River 10 mi (16 km) from its mouth, Perth was settled in 1829. It developed rapidly after the discovery of goldfields around Kalgoonie in the early 1890s and the opening of Fremantle Har¬ bour in 1897. It is now a major industrial centre with a rapidly expand¬ ing economy. The site of the 1987 America's Cup, it is the seat of the University of Western Australia and Murdoch University.

Perth City (pop., 1995 est.: 42,000), central Scotland. Located on the River Tay, northwest of Edinburgh, Perth was a Roman settlement; it became a royal burgh in 1210. It was the capital of Scotland until 1437, when King James I of Scotland was murdered there. At the Church of St. John the Baptist in 1559, John Knox denounced idolatry; the result was the plunder of Perth’s monasteries and altars. It was a Jacobite city dur¬ ing the Scottish uprisings of 1715 and 1745. The economy is based on whisky blending and distilling and on manufacturing. It is also an agri¬ cultural market centre.

pertussis See whooping cough

Peru officially Republic of Peru Country, western South America. Area: 496,225 sq mi (1,285,216 sq km). Population (2005 est.): 27,968,000. Capital: Lima. Almost half of the people are Quechua Indians,

nearly one-third are mestizos, and most of o ioo 200 mi th e remainder are Aymara Indians and

0 11 ’ 150 ’ ' 300 km' people of European ancestry. Languages:

Spanish, Quechua, Aymara (all official).

Religion: Christianity (predominantly Roman Catholic [official]; also Protestant). Currency: new sol. Peru is the third largest country in South America and may be divided into three geo¬ graphic regions from west to east: the coast, which consists of a long, narrow belt of desert lowlands; the Sierra (highlands), which is the Peru¬ vian portion of the Andes Mountains; and the Montana, the vast, forested eastern foothills and plains, consisting mainly of the tropical rainforests of the Amazon River basin. Peru has a developing mixed economy based largely on services, manufacturing, agriculture, and mining. Most indus¬ tries, including the petroleum industry, were nationalized in the late 1960s and early ’70s, but many were privatized again in the 1990s. Peru is a republic with one legislative house; its head of state and government is the president. Peru was the centre of the Inca empire, whose capital, Cuzco, was established in the 12th century. In 1533 the region was con¬ quered by Spanish adventurer Francisco Pizarro and thereafter was domi¬ nated by Spain for almost 300 years as the Viceroyalty of Peru. It declared its independence in 1821, and freedom was achieved in 1824. Peru was defeated by Chile in the War of the Pacific (1879-83). In 1941 a bound¬ ary dispute with Ecuador erupted into war, which gave Peru control over a larger part of the Amazon basin; further disputes ensued until the bor¬ der was demarcated again in 1998. The government was overthrown by a military junta in 1968; civilian rule was restored in 1980. The govern¬ ment of Alberto Fujimori dissolved the legislature in 1992 and promulgated a new constitution the following year. The government later successfully combated the Shining Path and Tupac Amaru rebel movements. Fujimori won a second term in 1995, but charges of fraud accompanied his elec-

© 2006 Encyclopaedia Britannica, Inc.

Peru ► pesticide I 1479

tion to a third term in 2000; his government crumbled later that year. In 2001 Alejandro Toledo became Peru’s first democratically elected presi¬ dent of Quechuan ethnicity.

Peru, Viceroyalfy of Second of the four viceroyalties established by Spain to govern its domains in the Americas. Founded in 1543, it initially included most of South America, but it lost jurisdiction over much of its territory to other viceroyalties over time. Peru, with its wealth of silver, was considered Spain’s most valuable possession in the Americas. By the late 18th century, Indian rebellions had destabilized the region, and the viceroyalty was unable to defend itself when the revolutionary forces of Jose de San Martin entered Lima in 1821. It became part of Peru and Chile in 1824. See also New Granada; New Spain; Viceroyalty of Rio de la Plata.

Perugia \pa-'rii-ja\ City (pop., 2001 prelim.: 148,575), capital of Umbria region, central Italy. Perugia lies north of Rome between the Tiber River and Lake Trasimeno. Founded by the Umbrians, it became one of the 12 major cities of the Etruscans; it later was ruled by Rome (from 310 bc). It became a Lombard duchy in ad 592. It was the centre of the great Umbrian school of painting, which flourished in the 15th century (see Perugino; Pinturicchio). Perugia played an active role in the Italian Risorg- imento and became part of Italy in 1860. It is an agricultural trade centre noted for its chocolate. There are notable remains of buildings and for¬ tifications from Etruscan and medieval times.

Perugino \,per-3-'je-no\ orig. Pietro di Cristoforo Vannucci (b.

c. 1450, Citta della Pieve, near Perugia, Romagna—d. February/March 1523, Fontignano, near Perugia) Italian painter. Born near Perugia (the source of his nickname), he was probably a pupil of Piero della Francesca and Andrea del Verrocchio. One of his most famous frescoes. Giving of the Keys to St. Peter (1481-82), in the Sistine Chapel, anticipated High Renaissance ideals in its compositional clarity and sense of spaciousness. He was at the height of his powers c. 1490-1500, when he painted the Crucifixion fresco for the convent of Santa Maria Maddalena dei Pazzi in Florence. Perugino’s art declined in his later years, and c. 1505 he left the highly critical Florentine art scene to work in Umbria. In 1508 he made a brief comeback by painting roundels on the ceiling of the Stanza dell’Incendio in the Vatican. The commission for the wall frescoes went to his pupil Raphael, who had already proved himself the greater artist.

Vision of St. Bernard, wood panel by Perugino, c. 1491-94; in the Alte Pi na- kothek, Munich.

COURTESY OF THE ALTE PINAKOTHEK, MUNICH

Perun \p y i-'run\ In ancient Slavic religion, the thunder god. He purified the earth and made it fertile, and he was the overseer of right and order. His powers were believed to be evident in the thunderbolt, the rattle of stones, the bellow of a bull, the bleat of a goat, and the touch of an ax

blade. In the Christian period the worship of Perun was gradually trans¬ ferred to St. Elijah, but folk belief in his powers continued. Sacrifices and communal feasts on July 20 in his honor were celebrated in Russia until modern times.

Perutz \p9-'riits. Max Ferdinand (b. May 19, 1914, Vienna, Austria—d. Feb. 6, 2002, Cambridge, Cambridgeshire, Eng.) Austrian- British biochemist. With John Cowdery Kendrew he founded the Medical Research Council Unit for Molecular Biology at the University of Cam¬ bridge. His discovery that hemoglobin’s structure changes when it picks up or releases oxygen led to the full understanding of the molecular mechanism of respiratory oxygen transport by hemoglobin. For his X-ray diffraction analysis of hemoglobin’s structure, Perutz and Kendrew shared the 1962 Nobel Prize for Chemistry. Perutz also used crystallography to study the flow of glaciers.

Pesaro Vpa-z'si-,r6\ ancient Pisorum City (pop., 2001 prelim.: 90,311), Marche region, north-central Italy. A seaport on the Adriatic Sea, Pesaro was destroyed by the Ostrogoths in ad 536. Rebuilt and fortified by the Byzantine general Belisarius as one of the cities of the Pentapolis, it was sold to the Sforza family in 1445. It became part of the Papal States in 1631. It was the birthplace of composer Gioacchino Rossini in 1792. In World War II Pesaro suffered heavily in the Allied advance of 1944, but many of its old buildings escaped with minor damage. It is a seaside resort surrounded by an agricultural area. Its museum of majolica houses the richest collection in Italy.

Peshawar \p9-'sha-w3r\ City (pop., 1998 est.: 988,055), capital of North-West Frontier province, Pakistan. It is located west of the Bara River near the Khyber Pass. Once the capital of the ancient Buddhist king¬ dom of Gandhara, it was a centre of the caravan trade with Afghanistan and Central Asia. It became the capital of the Indo-Scythian Kushan empire c. 1st century ad. It was captured by the Muslims in 988. By the 16th century Peshawar was ruled by the Afghans. It was under British control (1849-1947) and served as an important military base. The city is still militarily important; its ancient bazaar remains a meeting place for foreign merchants and traders.

Pessoa Vpes-'so-sV Fernando Antonio Nogueira (b. June 13, 1888, Lisbon, Port.—d. Nov. 30, 1935, Lisbon) Portuguese poet. While living in South Africa, where his stepfather was Portugal’s consul, Pes¬ soa became fluent in English. On returning to Lisbon he worked as a translator while contributing to avant-garde reviews, especially Orpheu (1915), the organ of Brazilian-Portuguese Modemismo, of which he became a leading aesthetician. Only after his death did the rich dream world of his poetry, peopled with fictional alter egos called “heteronyms,” become well known. His important volumes include Poesias de Fernando Pessoa (1942), Poesias de Alvaro de Campos (1944), Poemas de Alberto Caeiro (1946), and Odes de Ricardo Reis (1946).

pest Any organism, usually an animal, judged as a threat to humans. Most pests either compete with humans for natural resources or transmit disease to humans, their crops, or their livestock. Invertebrate pests include some protozoans, flatworms, nematodes, mollusks, arachnids, and especially insects. Mammals and birds can also be pests. Human activi¬ ties, such as monocultural farming practices, use of broad-spectrum pes¬ ticides, and introduction of exotic species, often result in the proliferation of pest species. Certain fungi, bacteria, and viruses are also considered pests. Plant pests are usually called weeds.

Pestalozzi X.pes-to-'lot-seV Johann Heinrich (b. Jan. 12, 1746, Zurich, Switz.—d. Feb. 17, 1827, Brugg) Swiss educational reformer. Between 1805 and 1825 he directed the Yverdon Institute (near Neucha- tel), which drew pupils and educators (including Friedrich Froebel) from all over Europe. His teaching method emphasized group rather than indi¬ vidual recitation and focused on such participatory activities as drawing, writing, singing, physical exercise, model making, collecting, mapmak¬ ing, and field trips. Among his ideas, considered radically innovative at the time, were making allowances for individual differences, grouping students by ability rather than age, and encouraging formal teacher train¬ ing.

pesticide Any toxic substance used to kill animals or plants that dam¬ age crops or ornamental plants or that are hazardous to the health of domestic animals or humans. All pesticides act by interfering with the target species’ normal metabolism. They are often classified by the type of organism they are intended to control (e.g., insecticide, herbicide, fungicide).

© 2006 Encyclopaedia Britannica, Inc.

1480 I pet ► Peter Damian

Some inadvertently affect other organisms in the environment, either directly by their toxic effects or via elimination of the target organism.

pet Any animal kept by humans for companionship or pleasure rather than for utility. The main distinction between pets and domesticated live¬ stock is the degree of contact between owner and animal. Another dis¬ tinction is the owner’s affection for the animal, which is often returned. Dogs are known to have been kept as pets since prehistoric times; cats, since the 16th century bc; and horses, since at least 2000 bc. Other com¬ mon pets include birds, rabbits, rodents, raccoons, reptiles, amphibians, and even insects. The trend toward making pets of exotic animals (e.g., monkeys and ocelots) is worrisome because owners can rarely provide for their needs, and the animals’ already precarious populations are fur¬ ther depleted when members are sold for pets.

PET See positron emission tomography

Petain \pa-'ta n \, (Henri-) Philippe (b. April 24, 1856, Cauchy-a-la- Tour, France—d. July 23, 1951, lie d’Yeu) French general. He served in the French army from 1876 and later taught at the war college. His suc¬ cessful defense in the Battle of Verdun (1916) made him a national hero, and in 1918 he became commander in chief and a marshal of France. After the war he was appointed vice president of the Supreme War Council (1920-30) and minister of war (1934). After the German invasion of France (1940), Petain was appointed premier at age 84. He concluded an armistice with Germany, and as head of Vichy France he attempted to obtain concessions by cooperating with the Germans. In 1942 the Ger¬ mans forced him to accept Pierre Laval as premier and he withdrew to a nominal role as head of state. After the Allied invasion of France, he fled to Germany. In 1945 he was tried and condemned to death; the sentence was commuted to life in prison, where he died at age 95.

Peten Itza \pe-,ten-et-'sa\, Lake Lake, northern Guatemala. It is about 22 mi (35 km) long and covers an area of about 40 sq mi (100 sq km). The region was a stronghold of the Maya Itza Indians, who were not con¬ quered by the Spanish until 1697. The lakeshore is now dotted with towns such as Flores and San Benito. Much of the surrounding land is covered with dense rainforest, but there is some cultivation of cacao, sugarcane, and tropical fruits around Flores.

Peter I (b. c. 903—d. Jan. 30, 969) Tsar of Bulgaria (927-969). The second son of Simeon I, he inherited the throne on his father’s death in 927. Early in his reign, Peter faced revolts by his brothers, which were suppressed, and he also endured raids by the Magyars, who crossed Bul¬ garia on their way to the Byzantine Empire. His reign, however, was gen¬ erally peaceful, and he made important gains against the Byzantines, receiving the title emperor from them. He also forced the Byzantines to recognize the independence of the Bulgarian church, and he married the granddaughter of the Byzantine emperor Romanus I Lecapenus. In 965 war broke out with the Byzantines; Peter subsequently suffered a stroke and

W retired to a monastery, where he died two years later. Canonized by the

Bulgarian Orthodox church, Peter was deeply religious and an active church builder. During his reign, the Bogomil heresy first appeared.

Peter I Russian Pyotr Alekseyevich known as Peter the Great

mm (b. June 9, 1672, Moscow, Russia—d. Feb. 8, 1725, St. Petersburg) Tsar

9 of Russia (1682-1725). Son of Tsai- Alexis, he reigned jointly with his half

brother Ivan V (1682-96) and alone from 1696. Interested in progressive influences from western Europe, he visited several countries there (1697- 98). After returning to Russia, he introduced Western technology, mod¬ ernized the government and military system, and transferred the capital to the new city of St. Petersburg (1703). He further increased the power of the monarchy at the expense of the nobles and the Orthodox church. Some of his reforms were implemented brutally, with considerable loss of life. Suspecting that his son Alexis was conspiring against him, he had Alexis tortured to death in 1718. He pursued foreign policies to give Rus¬ sia access to the Baltic and Black seas, engaging in war with the Otto¬ man Empire (1695-96) and with Sweden in the Second Northern War (1700-21). His campaign against Persia (1722-23) secured for Russia the southern and western shores of the Caspian Sea. In 1721 he was proclaimed emperor; his wife succeeded him as the empress Catherine I. For raising Russia to a recognized place among the great European pow¬ ers, Peter is widely considered one of the outstanding rulers and reform¬ ers in Russian history, but he has also been decried by nationalists for discarding much of what was unique in Russian culture, and his legacy has been seen as a model for Joseph Stalin’s brutal transformation of Rus¬ sian life.

Peter I (b. July 11, 1844, Belgrade, Serbia—d. Aug. 16, 1921, Topcider, near Belgrade, Kingdom of Serbs, Croats, and Slovenes) King of Serbia (1903—18) and of the Kingdom of Serbs, Croats, and Slovenes (later Yugoslavia) from 1918. The son of Prince Alexander Karadjordjevic, who was forced to abdicate in 1858, he lived with his family in exile. He fought with the French army in the Franco-Prussian War and with the Serbian revolt against the Turks (1875). After the assassination of Alexander Obrenovic (1903), Peter was elected king of Serbia. He advocated a con¬ stitutional government and won recognition for his liberal policies. In World War I, he allied Serbia with France and Russia but was defeated by the Central Powers. In 1918 he returned to Belgrade and was pro¬ claimed king of the Serbs, Croats, and Slovenes.

Peter II Russian Pyotr Alekseyevich (b. Oct. 23, 1715, St. Peters¬ burg, Russia—d. Jan. 29, 1730, Moscow) Tsar of Russia (1727-30). The grandson of Peter I, he was named heir to the throne by Catherine I and on her death was crowned at age 11. Peter’s regency was directed by Alek¬ sandr Menshikov. He fell under the influence of the aristocratic Dolgoruky family, which ousted Menshikov as regent, moved the capital to Moscow (1728), and arranged Peter’s betrothal to one of its princesses. On the day set for the wedding, Peter died of smallpox at age 14.

Peter II (b. Sept. 6, 1923, Belgrade, Kingdom of Serbs, Croats, and Slovenes—d. Nov. 3, 1970, Los Angeles, Calif., U.S.) Last king of Yugo¬ slavia. The son of Alexander I, he became titular king on his father’s assassination (1934), but he ruled under the regency of his uncle Prince Paul (1893-1976). After a coup deposed Paul (1941), Peter ruled for sev¬ eral weeks until the German invasion forced him to flee to London. He led a government-in-exile until the Yugoslav monarchy was abolished in 1945. He moved to the U.S., where he worked in public relations.

Peter III Spanish Pedro known as Peter the Great (b. 1239—d. Nov. 11, 1285, Villafrance del Panades, Catalonia) King of Aragon (1276- 85) and of Sicily (as Pedro I, 1282-85). He married the Hohenstaufen heiress of Sicily (1262) and ended the Sicilian revolt (1282), becoming king despite Guelph and papal opposition (see Sicilian Vespers). Unhappy with his Sicilian venture, nobles and municipalities in Aragon forced Peter to confirm their legal rights and to diminish crown rights. In 1285 he defeated Philip III of France, who had invaded Aragon in an effort to dethrone him.

Peter III Russian Pyotr Fyodorovich orig. Karl Peter Ulrich, duke von Holstein-Gottorp (b. Feb. 21, 1728, Kiel, Holstein- Gottorp—d. July 18, 1762, Ropsha, near St. Petersburg, Russia) Tsar of Russia (1762). Grandson of Peter I, the young duke was brought to Rus¬ sia by his aunt Elizabeth when she became empress (1741). Proclaimed the heir to the Russian throne, he was unpopular at court for his pro-Prussian attitude. After he succeeded Elizabeth (1762), he reversed her foreign policy, making peace with Prussia and withdrawing from the Seven Years' War. He offended the Orthodox church by trying to force it to adopt Lutheran practices. After six months he was forced to abdicate by a group of nobles, in collusion with his own wife, Catherine (later Catherine II), and Count Grigory Orlov, and was murdered while in the conspirators’ custody.

Peter IV Spanish Pedro known as Peter the Cruel (b. Sept. 5, 1319, or Sept. 15, 1317, Balaguer, Catalonia—d. Jan. 5, 1387, Barcelona) King of Aragon (1336-87). He took the Balearic Islands and Roussillon from Majorca (1343-44), defeated the Aragonese nobles (1348), and became duke of Athens and Neopatras (1380). He waged war against Castile (1356-66) but failed to gain any territory; after 1369 France favoured Castile over Aragon. Peter tried to maintain neutrality in the Hundred Years' War, and he quarreled with his heir, the future John I, who became the tool of French intrigues.

Peter, Saint See Saint Peter the Apostle

Peter Damian Vda-me-3n\, Saint (b. 1007, Ravenna—d. Feb. 22, 1072, Faenze; feast day February 21) Italian cardinal and Doctor of the Church. He was prior of Fonte Avellana in the Apennines before being named a cardinal in 1057. A leading monastic reformer and ascetic, he played an important role in the promotion of apostolic poverty and in sup¬ port of papal reformers who sought to enforce clerical celibacy and abolish simony. He defended Pope Alexander II against the antipope Honorius II and reconciled Alexander with the city of Ravenna. He was also sent as a papal legate to resolve disputes in Milan and Cluny, Burgundy, and he played a key role in the formulation of the papal election decree of 1059.

© 2006 Encyclopaedia Britannica, Inc.

Peter Lombard ► petition I 1481

Peter Lombard (b. c. 1100, Novara, Lombardy—d. Aug. 21/22, 1160, Paris) French bishop and theologian. He studied in Bologna and taught the¬ ology in the school of Notre-Dame, Paris. He was consecrated bishop of Paris in 1159. His Four Books of Sentences (1148-51), a systematic col¬ lection of teachings of the Church Fathers and opinions of medieval theo¬ logians, served as the standard theological text of the Middle Ages. In it Peter touched on every doctrinal issue, from God and the Trinity to the four “last things” (death, judgment, hell, and heaven). He asserted that sacra¬ ments are the cause and not merely the signal of grace and that human actions may be judged good or bad according to their cause and intention.

Peter the Apostle, Saint orig. Simon (d. c. ad 64, Rome) Disciple of Jesus, recognized as the leader of the Twelve Apostles. Jesus called him Cephas (Aramaic for “Rock”; rendered in Greek as “Petros”) and said “Upon this rock I will build my church” (Matthew 16:18). When Jesus was arrested, according to the biblical account, Peter denied him three times, as Jesus had foretold. Accounts of Peter’s life and ministry rely on the four Gospels, the Acts of the Apostles, the epistles of Peter, and the epistles of St. Paul. Peter worked with Paul in Antioch and later carried on missionary work in Asia Minor. According to tradition, he eventually went to Rome, where he suffered martyrdom by being crucified upside down. Saint Peter's Basilica is said to have been built on the site of his grave in Rome. In Roman Catholicism he is regarded as the first in the unbroken succession of popes. Jesus’ promise to give him the “keys of the kingdom” led to the popular perception of Peter as the gatekeeper of heaven. The Roman Catholic church celebrates five feast days in honour of Peter, and in each the name of Paul is associated.

Peter the Cruel See Peter IV

Peter the Great See Peter I (Russia), Peter III (Aragon)

Peter the Great Bay Inlet, Sea of Japan (East Sea), northwestern Pacific Ocean, in extreme southeastern Russia. It extends for 115 mi (185 km) from the mouth of the Tumen River northeast across to Cape Povorotny. The bay reaches inland for 55 mi (88 km) and contains the port of Vladi¬ vostok. The bay freezes from early December to mid-April.

Peter the Hermit (b. c. 1050, probably Amiens—d. July 8, 1115, Huy, Flanders) French ascetic and one of the most important preachers of the First Crusade. A charismatic ascetic, he preached widely in Europe in sup¬ port of the First Crusade and led his enthusiastic followers to Constan¬ tinople in 1096. They advanced to Nicomedia, but Peter was unable to maintain discipline; he returned to Constantinople to ask for help from Alexius I, and in his absence his army was annihilated by the Turks. Peter reached Jerusalem in 1099 and afterwards returned to France, where he became prior of an Augustinian monastery.

Peter the Venerable (b. c. 1092, Montboissier, Auvergne, Arles—d. Dec. 25, 1156, Cluny, Burgundy) French abbot of Cluny (from 1122). He joined Bernard de Clairvaux in supporting Pope Innocent II and weakened the position of the antipope Anacletus II. He befriended Peter Abelard and reconciled him to Bernard and the pope. Peter’s reforms restored Cluny to its prominence among the religious establishments of Europe. He also wrote numerous letters and treatises against heresy, the Jews, and the Muslims and commissioned the first Latin translation of the Qur’an.

Peterhof See Petrodvorets

Peterloo Massacre (Aug. 16,1819) Brutal dispersal of a meeting held on St. Peter’s Fields in Manchester, Eng. Called to protest unemployment and high food prices and demand parliamentary reform, the meeting drew about 60,000 people, including many women and children. Alarmed by its size, city officials ordered the city’s volunteer cavalry to arrest the speakers. The untrained cavalry also attacked the peaceable crowd with sabres, and professional soldiers were sent to join the attack. After a 10-minute rout, about 500 people lay injured and 11 were dead. The inci¬ dent (likened to Waterloo) came to symbolize Tory tyranny.

Peters, Carl (b. Sept. 27, 1856, Neuhaus an der Elbe, Hanover—d. Sept. 10, 1918, Bad Harzburg, Ger.) German explorer and colonizer in East Africa. After studying British principles of colonization, he founded the Society for German Colonization (1884) and made treaties with chiefs in East Africa to cede their territories to him. He helped establish the Ger¬ man East African protectorate of Tanganyika and formed the German East Africa Company in 1885. He served as imperial high commissioner for Kilimanjaro (1891—97) and explored the Zambezi River (1899-1901), where he discovered relics of ancient cities and gold mines.

Peter's Pence In medieval England, an annual tax of a penny paid by landowners to the papal treasury in Rome. Peter’s Pence was instituted during the 7th or 8th century and continued until the 16th century. It also existed in several northern European kingdoms.

Petersburg Campaign (1864-65) Series of military operations in southern Virginia at the end of the American Civil War. The rail centre of Petersburg, Va., was a strategic defense point near the Confederate capi¬ tal of Richmond. In June 1864 the Union army began a siege of both cit¬ ies, and each side built fortifications 35 mi (56 km) long. Confederate troops under Robert E. Lee held the cities, but supplies were scarce and Lee’s 50,000 troops were immobilized by lack of horses. In April 1865 the 120,000 Union troops under Ulysses S. Grant drove the Confederates behind Petersburg’s inner defenses, forcing the evacuation of both cities. Soon thereafter the Confederates surrendered at Appomattox Court House.

Peterson, Oscar (Emmanuel) (b. Aug. 15, 1925, Montreal, Que., Can.) Canadian jazz pianist and composer. Peterson grew up in Montreal and studied classical piano. His jazz playing, influenced by Art Tatum and Nat King Cole, is characterized by cascades of notes and an effervescent swing. After his Carnegie Hall debut in 1949 he became one of the busi¬ est pianists in jazz, in demand as an accompanist, solo pianist, and leader of his own trio. An outstanding, extroverted improviser and sensitive accompanist, Peterson demonstrates in his performance his roots in swing as well as bebop.

Peterson, Roger Tory (b. Aug. 28, 1908, Jamestown, N.Y., U.S.—d. July 28, 1996, Old Lyme, Conn.) U.S. ornithologist. He started drawing birds in high school. His Field Guide to the Birds (1934), illustrated with paintings that stressed the features that best identified a species in the field, greatly stimulated public interest in bird study in the U.S. and Europe. Many other guides followed. More responsible than any other person for fostering a widespread awareness of birds by the American public, he received such awards as the American Ornithologists’ Union’s Brewster Medal (1944) and the World Wildlife Fund’s Gold Medal (1972).

Petipa \pa-te-‘pa\, Marius (b. March 11, 1818, Marseille, Fr.—d. July 14, 1910, Gurzuf, Ukraine, Russian Empire) French-born Russian dancer and choreographer. He received his early training from his ballet-master father and was a principal dancer in France, Belgium, and Spain before joining the Imperial Theatre in St. Petersburg in 1847. There he also cre¬ ated several ballets, including The Pharaoh’s Daughter, which led to his appointment as chief choreographer in 1869. By his retirement in 1903, he had produced more than 60 ballets for the imperial theatres in St. Petersburg and Moscow—including Don Quixote (1869), La Camargo (1872), Sleeping Beauty (1890), Swan Lake (1895), and The Seasons (1900)—which formed the core of the classical Russian repertoire.

Petit \po-'te\, Roland (b. Jan. 13, 1924, Villemomble, Fr.) French dancer and choreographer. He danced with the Paris Opera Ballet (1940- 44) and then formed several companies, with which he toured Europe and the U.S. His dramatic ballets combined fantasy with elements of contemporary realism and included The Strolling Players (1945), The Young Man and Death (1946), and Carmen (1949). He choreographed dances for films in the 1950s, and he later staged revues featuring his wife, Zizi Jeanmaire. From 1973 to 1997 he was director of the Ballet de Marseille.

petit Vpe-te\ jury or trial jury Group chosen from the citizens of a district to try a question of fact at issue in a trial. Though petit juries in England and the U.S. historically have contained 12 members, there is no uniform number. Numerical requirements for a valid verdict vary (e.g., unanimity in most courts in the U.S., a majority in Scotland and Italy, two-thirds in Portugal). The petit jury is the standard jury for civil and criminal trials. It has less discretion than is often imagined. The trial judge supervises it, rules on what evidence it may view and which laws are applicable, and sometimes directs or, at the end of the trial, sets aside its verdict. See also grand jury.

petition Written instrument directed to an individual, government offi¬ cial, legislative body, or court in order to seek redress of grievances or to request a favour. In some jurisdictions, petitions brought by a sufficient number of people (represented by their signatures) are used to place a candidate on a ballot, to submit an issue to the electorate (see referendum and initiative), or to exert pressure on legislators to vote in a certain way. In the U.S., the right to petition is guaranteed by the 1st Amendment to the Constitution.

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1482 i Petition of Right ► Petrograd

Petition of Right (1628) Petition sent by Parliament to King Charles I complaining of a series of breaches of law. The petition sought recognition of four principles: no taxation without the consent of Parliament, no impris¬ onment without cause, no quartering of soldiers on subjects, and no martial law in peacetime. To continue receiving subsidies for his policies, Charles was compelled to accept the petition, but he later ignored its principles.

Petofi Vpet-ce-fe\, Sandor (b. Jan. 1, 1823, Kiskoros, Hung.—d. prob¬ ably 1856, Siberia) Hungarian poet and revolutionary. He became famous with his first poetry volume, Versek (1844). Before the revolution of 1848 he wrote poems that glowed with political passion; one of them, “Talpra magyar” (“Rise, Hungarian”), became an anthem. He disappeared in battle and was assumed dead in 1849, but archives opened in the 1980s revealed that he was marched to Siberia and died there. His works are character¬ ized by realism, humour, descriptive power, and a peculiar vigour and have a direct style adapted from national folk songs. Janos vitez (1845), an entrancing fairy tale, is his most popular epic.

Petra Vpe-tr q\ Arabic Batra Ancient city, Middle East. Located in what is now southwestern Jordan, it was the capital of the Nabataean kingdom until its defeat by the Romans in ad 106. It then became part of the Roman province of Arabia. After several centuries as a flourishing trade centre, it declined with the shifting of trade routes away from the city. It was captured by the Muslims in the 7th century. Its ruins were rediscovered in 1812 by the Swiss traveler Johann L. Burckhardt. Excavations since the mid-20th century have revealed many rock-cut monuments, including tombs with elaborate facades carved in the rose, crimson, and purple sandstone of the surrounding hills. Petra was designated a UNESCO World Heritage site in 1985.

The Nabataean rock-cut monument of Ad-Dayr, Petra, Jordan.

BRIAN BRAKE FROM RAPHO/PHOTO RESEARCHERS-EB INC.

Petrarch Vpe-.trark, 'pe-,trark\ Italian Francesco Petrarca (b. July 20, 1304, Arezzo, Tuscany—d. July 18/19, 1374, Arqua, near Padua, Car¬ rara) Italian scholar, poet, and humanist. After 1326 he abandoned the study of law for his true interests, literature and the religious life. He took minor ecclesiastical orders and moved to Avignon, where in 1327 he first saw Laura, the idealized subject of his chaste love and of his celebrated Italian love lyrics; mainly sonnets and odes written over some 20 years, most were included in his Canzoniere or Rime (1360). The greatest scholar of his age, especially of Classical Latin, he traveled widely, visiting learned men, searching out manuscripts, and undertaking diplomatic missions. He strongly advocated the continuity between Classical culture and the Chris¬ tian message; in combining the two ideals he is considered the founder and a great representative of humanism. His Latin works, reflecting his religious and philosophical interests, include On Illustrious Men (begun c. 1337), the epic poem Africa (begun c. 1338), the autobiographical treatise Petrarch’s Secret (written 1342-58), De vita solitaria (1345-47; “The Life of Soli¬ tude”), and Epistolae metricae (begun c. 1345; “Metrical Letters”). After 1367 he lived in and near Padua. His influence on European literature was enormous and lasting, and his deep consciousness of the Classical past as a source of literary and philosophical meaning for the present was of great importance in paving the way for the Renaissance.

petrel Any of numerous seabirds (order Procellariiformes, particularly family Procellariidae), including 24 species (genera Pterodroma and Bul- weria ) called gadfly petrels because of their fluttering flight. Most are dark above and light below, with long wings and a short, wedge-shaped tail. They nest in colonies on tropical and subtropical islands. Both parents tend the single chick until it is almost fully fledged. During the nonbreed¬ ing season, petrels roam the open ocean, eating squid and small fishes. Species in the family Pelecanoididae are called diving petrels. See also FULMAR, SHEARWATER, STORM PETREL.

Petrie Vpe-treV Sir (William Matthew) Flinders (b. June 3, 1853, Charlton, near Greenwich, London, Eng.—d. July 28, 1942, Jerusalem) British archaeologist who made valuable contributions to the techniques of excavation and dating. During excavations in Egypt in the mid 1880s Petrie developed a sequence dating method, based on a comparison of potsherds at various levels, that made possible the reconstruction of ancient history from material remains. His excavations, together with those of Heinrich Schliemann at Troy, marked the beginning of the exami¬ nation of successive levels of a site, rather than the previously haphazard digging. Petrie made many important discoveries in Egypt and Palestine. His Methods and Aims in Archaeology (1904) was the definitive work of its time. He taught at the University of London (1892-1933).

Petrified Forest National Park National park, eastern Arizona, U.S. Established as a national monument in 1906 and as a national park in 1962, it has an area of 146 sq mi (378 sq km). It features extensive exhibits of petrified wood in several “forest” areas, fossilized leaves, plants, and broken logs, and the Painted Desert. Other features include petroglyphs and ancient Pueblo Indian ruins.

petrified wood Fossil formed by the infiltration of minerals into cavi¬ ties between and within cells of natural wood, usually by silica (silicon dioxide, Si0 2 ) or calcite (calcium carbonate, CaC0 3 ). Often this replace¬ ment of organic tissue by mineral deposits is so precise that the internal structure as well as the external shape is faithfully represented; sometimes even the cell structure may be determined.

Petrobras \'pe-tro-,bras\ officially Petroleo Brasileiro SA Brazil¬ ian oil and natural-gas company, the largest corporation in South America. It was founded in 1953 as a government-owned monopoly to prospect, extract, and refine domestic petroleum and to transport that oil and its derivatives. A government agency sets its policies and oversees its devel¬ opment. Although mainly devoted to developing petroleum sources in Brazil, Petrobras also has interests in the Middle East, North Africa, and Colombia. In 1995, as part of a campaign to privatize state-owned indus¬ tries, the Brazilian government ended the company’s monopoly and allowed foreign competition. Petrobras subsequently developed joint ven¬ tures with foreign businesses.

petrochemical Strictly, any of a large class of chemicals (as distinct from fuels) derived from petroleum and natural gas. The category has been broadened to include a much larger range of organic compounds and a few inorganic compounds (including carbon black, sulfur, and ammonia). Some materials cannot be classifed unequivocally because they have alter¬ native sources (benzene from coal, ethanol from fermentation). Like crude oil and natural gas, most petrochemicals consist mainly of carbon and hydrogen and are called hydrocarbons. Petrochemicals used as raw mate¬ rials (feedstocks) include ethylene, propylene, butadiene, benzene, toluene, xylene, and naphthalene. Among the myriad petrochemical products are plastics (e.g., polyethylene, polypropylene, polystyrene), soaps and deter¬ gents, solvents, drugs, fertilizers, pesticides, explosives, synthetic fibres and rubberss, paints, epoxies, flooring and insulating materials, luggage, and recording disks and tapes.

Petrodvorets \,pyi-tr3-dva-'ryets\ formerly (until 1944) Peterhof City (pop., 1995 est.: 82,000), northwestern Russia. Located near St. Petersburg, it was founded by Peter I the Great as a country estate in 1709. After visiting France in 1717, he decided to create a residence that would rival the Palace of Versailles. The Baroque Grand Palace (1714-28) was designed by Domenico Trezzini, and its gardens by Alexandre Le Blond (1679-1719). It became the most lavish and popular of the Russian royal summer residences. Today the Grand Palace (now a museum) and the vast park, with 39 mi (63 km) of canals that connect the intricate system of fountains, are part of the 2,500-acre (1,000-hectare) preserved area in the city of Petrodvorets.

Petrograd See Saint Petersburg

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petrol ► peyote I 1483

petrol See gasoline

Petroleos de Venezuela ^pe-tro-'la-os-tha-.ve-nsz-'wa-lsV, SA (PDVSA) State-owned Venezuelan energy company with interests in oil, natural gas, coal, and petrochemicals. It was created in 1976 through the nationalization of Venezuela’s petroleum industry, which had been con¬ trolled by foreign companies since the end of World War I. Petroleos de Venezuela engages in the exploration, refining, and marketing of oil, pet¬ rochemicals, and natural gas in many parts of the world. Through its acquisition of CITGO Petroleum in 1990, PDVSA became a leading sup¬ plier of gasoline and other petroleum products in the U.S. Given the scale of its operations, PDVSA usually earns the largest share of Venezuela’s foreign currency.

petroleum or crude oil Complex mixture of hydrocarbons derived from the geologic transformation and decomposition of plants and ani¬ mals that lived hundreds of millions of years ago. As a technical term, petroleum encompasses the liquid (crude oil), gaseous (natural gas), and viscous or solid (bitumen, asphalt) forms of hydrocarbons that occur in the Earth, but the meaning is often restricted to the liquid oil form. Crude oil and natural gas are the most important primary fossil fuels. Asphalt has been used since ancient times to caulk ships and pave roads. In the mid 1800s petroleum began to replace whale oil in lamps, and the first well specifically to extract it was drilled in 1859. The development of the auto¬ mobile gave petroleum a new role as the source of gasoline. Petroleum and its products have since been used as fuels for heating, for land, air, and sea transport, and for electric power generation and as petrochemical sources and lubricants. Crude oil and natural gas, produced mostly in Saudi Arabia, the U.S., and Russia, now account for about 60% of world energy consumption; the U.S. is by far the largest consumer. At present rates of consumption, the known supply will be exhausted by the mid 21st century. Petroleum is recovered from drilled wells, transported by pipe¬ line or tanker ship to refineries, and there converted to fuels and petro¬ chemicals.

petroleum trap Subsurface reservoir of petroleum. The oil is always accompanied by water and often by natural gas; all are confined in porous rock. The natural gas, being lightest, occupies the top of the trap and is underlain by the oil and then the water. A layer of impervious rock, called the roof rock, prevents the escape of the petroleum. The part of the trap that is actually occupied by the oil and gas is called the petroleum res¬ ervoir.

petrology Scientific study of rocks, including their composition, tex¬ ture, and structure; occurrence and distribution; and conditions of origin. Petrology is concerned with all three major types of rocks: igneous, meta- morphic, and sedimentary. The subdiscipline of experimental petrology involves synthesizing rocks in the laboratory to ascertain the physical and chemical conditions under which they form. The subdiscipline of petrog¬ raphy is concerned primarily with the systematic study and description of rocks using a petrographic microscope.

Petronas \pe-'tro-nos\ Towers Twin stainless-steel-clad skyscrapers, linked by a skybridge, in Kuala Lumpur, Malaysia. Designed by Cesar Pelli (b. 1926) and completed in 1998, the circular, step-tapered towers house the headquarters of Malaysia’s national petroleum company. Each tower is 88 stories high, has a structural frame of high-strength, steel- reinforced concrete, and reaches a height of 1,483 ft (451.9 m)—a figure that includes a pinnacle and steel spire atop each. In 1996, after achiev¬ ing their full height, the towers were considered the world’s tallest build¬ ings, surpassing the then-tallest Sears Tower; they, in turn, were superseded in 2003 by the Taipei 101 (Taipei Financial Center) building in Taipei, Taiwan, that rose to 1,667 ft (508 m).

Petronius Arbiter, Gaius orig. Titus Petronius Niger (d. ad 66)

Roman writer. Of a noble family, Petronius belonged to a class of idle pleasure-seekers, but he served ably as governor of the Asian province of Bithynia and as consul in Rome. After being appointed Nero’s authority on taste (hence “Arbiter”), he was accused of plotting to kill the emperor and, though innocent, committed suicide. He is the reputed author of the Satyricon, a comic picaresque novel vividly portraying contemporary Roman society through the escapades of a disreputable trio of adventur¬ ers, with unrelated stories and the author’s commentaries on Roman life interspersed.

Petty, Richard (b. July 2, 1937, Level Cross, N.C., U.S.) U.S. stock- car racer. He entered professional stock-car racing in 1958. In his long

professional career he won 200 races. In 1975 he set the NASCAR record of 13 victories in one season. “King Richard” also won seven Daytona 500 races and seven NASCAR Grand National championships. His father, son, and grandson were all NASCAR racers.

Petty, Sir William (b. May 26, 1623, Romsey, Hampshire, Eng.—d. Dec. 16, 1687, London) British political economist and statistician. He gave up a life at sea to study medicine, and taught anatomy at the Uni¬ versity of Oxford. He founded mines, ironworks, and fisheries in Ireland. He was also responsible for several inventions and was a founder of the Royal Society. Petty was an originator of political arithmetic, which he defined as the art of reasoning by figures upon things relating to govern¬ ment. In his best-known work, Treatise of Taxes and Contributions (1662), he favoured giving free rein to the forces of individual self-interest but declared the maintenance of a high level of employment to be a duty of the state. He also argued that the labour necessary for production was the main determinant of exchange value.

petunia Any of many species of flowering plants in the genus Petunia , in the nightshade family, which originated in South America. The innumer¬ able varieties of showy, trumpet-shaped flowers are immensely popular. There are two types: the compact, erect sort seen in summer garden beds, and the sprawling, long-stemmed sort seen in hanging baskets and win¬ dow boxes. From early summer until frost, petunias bloom profusely with single or double blossoms; crisped, fringed, or ruffled flowers; and spec¬ tacular hues from pure white to deep crimson or purple, speckled or veined in contrasting colours. Leaves are soft, flabby, and covered with fine, sticky hairs. Technically perennials, petunias are most often grown as annuals.

Pevsner \'pevz-nor\, Antoine orig. Natan Borisovich Pevzner

(b. Jan. 18, 1886, Oryol, Russia—d. April 12, 1962, Paris, France) Russian-born French sculptor and painter. After travels to Paris and Oslo, he returned to become a professor at Moscow’s school of fine arts. He helped form the Suprematist group, and in 1920 he and his brother, Naum Gabo, issued the Realist Manifesto of Constructivism. He settled in Paris in 1923. He used zinc, brass, copper, and celluloid for his early sculp¬ tures; later he relied mainly on parallel arrays of bronze wire soldered together to form plates, which he joined to form intricate shapes.

Pevsner Vpefs-norX, Sir Nikolaus (b. Jan. 30,1902, Leipzig, Ger.—d. Aug. 18, 1983, London, Eng.) German-born British art historian. He stud¬ ied at various German universities and taught at Gottingen University (1929-33) before moving to England to escape Nazism. There he taught at the Universities of London, Oxford, and Cambridge. He is best known for his writings on architecture, especially his 46-volume series of county- by-county guides, The Buildings of England (1951-74), one of the great achievements of 20th-century art scholarship. He conceived and edited the Pelican History of Art series (1953- ); many of these individual vol¬ umes have become classics.

pewter Tin-based alloy used to make domestic utensils. Pewter dates back at least 2,000 years, to Roman times. Ancient pewter contained about 70% tin and 30% lead. Such pewter, also called black metal, darkened greatly with age, and the lead readily leached out in contact with acidic foods. Pewter with little or no lead is of finer quality, and alloys that include antimony and bismuth are more durable and shinier. Modem pew¬ ter is about 91% tin, 7.5% antimony, and 1.5% copper; the absence of lead makes it safe to use for foods and beverages. The surface of modem pewter is bluish white with either a bright finish or a soft, satin sheen. It resists tarnish, retaining its colour and finish indefinitely.

peyote \pa-'o-te\ Either of two species of the genus Lophophora in the cactus family, native to North America, almost exclusively to Mexico. The body of the peyote cac¬ tus is spineless, soft, usually blue- green, and only 3 in. (8 cm) wide and 2 in. (5 cm) tall. The more common species, mescal (L. williamsii), has pink to white flowers. L. diffusa, more primitive, has white to yellow flowers and a yellow-green body.

Well known for its hallucinogenic effects (primarily due to the alkaloid mescaline), peyote figures promi¬ nently in old and recent religious

Peyote (Lophophora williamsii )

DENNIS E. ANDERSON

© 2006 Encyclopaedia Britannica, Inc.

1484 I peyotism ► pharmacology

rituals of certain American Indian peoples. The sale, use, or possession of dried mescal buttons (flowering heads) or live plants is prohibited by law in many places.

peyotism See Native American Church

PH Quantitative measure of the strength of the acidity or alkalinity (see acid, base) of a solution. It is defined as the negative common logarithm of the concentration of hydrogen ions [H + ] in MOLEs/litre: pH = -log 10 [H + ]. The letters of its name are derived from the absolute value of the power ip) of the hydrogen ion concentration ( H ). The product of the con¬ centrations in water of H + and OH - (the hydroxide ion) is always about 10 -14 . The strongest acid solution has about 1 mole/litre of H + (and about 10 -14 of OH - ), for a pH of 1. The strongest basic solution has about 10 -14 moles/litre of H + (and about 1 of OH - ), for a pH of 14. A neutral solu¬ tion has about 10 -7 moles/litre of both H + and OH - , for a pH of 7. The pH value, measured by a pH meter, titration, or indicator (e.g., litmus) strips, helps inform chemists of the nature, composition, or extent of reac¬ tion of substances, biologists of the composition and environment of organisms or their parts or fluids, physicians of the functioning of bodily systems, and agronomists of the suitability of soils for crops and any treatments needed. The pH is now defined in electrochemical terms (see electrochemistry).

Phaedra Vfe-dro\ In Greek legend, the daughter of King Minos. She became the second wife of Theseus after he abandoned her sister Ariadne. She later fell in love with her stepson Hippolytus; rejected, she accused him of rape. He was killed, and she hanged herself.

Phaedrus \'fe-dros\ (b. c. 15 bc, Thrace—d. c. ad 50, Italy) Roman fabulist. A slave by birth, Phaedrus became a freedman in Augustus’s household. He was the first writer to Latinize whole books of fables, pro¬ ducing free versions in iambic metre of Greek prose fables that were then circulating under the name of Aesop. Phaedrus’ s renderings, noted for their charm, brevity, and didacticism, became very popular in medieval Europe; they include such favourites as “The Fox and the Sour Grapes” and “The Wolf and the Lamb.”

Phaethon Vfa-s-thonN In Greek mythology, the son of Helios, the sun god, and a nymph. Taunted as illegitimate, Phaethon asked for permission to drive the chariot of the sun through the heavens for a single day in order to prove that Helios was his father. He proved unable to control the horses, and, after making a gash in the heavens that became the Milky Way, he rode too close to earth and began to scorch it. To prevent further damage, Zeus hurled a thunderbolt, killing him.

Phag-mo-gru family Vfag-mo-gru\ Tibetan family that in the 14th century liberated Tibet from Mongol control. At that time Tibet was gov¬ erned by lamas from the Sa-skya monastery who resided at the Mongol (Yuan) court in China. Under Byang-chub rgyal-mtshan (1302-1364), the Phag-mo-gru liberated central Tibet. For the next 100 years, a semblance of central authority was reestablished in the country.

phage See bacteriophage

phalanger See possum

phalanx \'fa-,laqks\ Tactical formation consisting of a block of heavily armed infantry standing shoulder to shoulder in files several ranks deep. First used by the Sumerians and fully developed by the ancient Greeks, it is viewed today as the beginning of European military development. The Greek city-states adopted a phalanx eight men deep during the 7th century bc. The spectacle of Greek hoplites marching forward in solid ranks was frightening to the enemy, but the phalanx was difficult to maneuver and easily thrown into confusion if its ranks were broken.

phalarope Vfa-l3- l rop\ Any of three species (genus Phalaropus, fam¬ ily Scolopacidae) of slim-necked shorebirds, 6-10 in. (25-25 cm) long, with lobed toes and a straight, slender bill. In summer, their gray-and- white plumage has red markings. Females fight for nesting territory and court the males; males, smaller and duller, do all the nesting duties and lead the young south in autumn. Two species breed around the Arctic Circle and winter on tropical oceans, where they are known as sea snipe. Wilson’s phalarope (P. tricolor) breeds in western North America and migrates to the Argentine pampas.

Phan Boi Chau Vpan-'boi-'chauX or Phan Giai San Vpan-'gyl-'sanV orig. Phan Van San (b. 1867, Nghe An province, Viet.—d. Sept. 29, 1940, Hue) Vietnamese resistance figure. Son of a poor scholar, he

received a doctorate in 1900, by which time he was already a firm nation¬ alist. Opposed to French rule in Vietnam, he organized efforts to place the nationalist Prince Cuong De (1882-1951) on the throne. In 1905 he moved his resistance movement to Japan, where he met Sun Yat-sen and Phan Chau Trinh. His monarchist scheme failed, as did a plan to assassi¬ nate the governor-general of French Indochina, and Chau was imprisoned in 1914-17. Hundreds of Vietnamese protested when he was arrested again in 1925; subsequently released, he spent his remaining years in quiet retirement.

Phan Chau Trinh Vpan-'chii-'trinN (b. 1872, Tay Loc, Quang Nam province, Viet.—d. March 24, 1926, Saigon) Vietnamese nationalist leader and reformer. Trinh, who fought in the resistance movement against the French even as a boy, came to believe that modernization was a pre¬ requisite for developing an autonomous state, and he thus made modern¬ ization his primary goal. He urged replacing the civil service system with vocational schools and commercial firms, but his attempts to persuade the French to undertake major reforms failed, and he was twice imprisoned. He was mourned as a national hero after his death. See also Phan Boi Chau.

Phanerozoic \,fa-n3-r3-'zo-ik\ Eon Span of geologic time from c. 543 million years ago, the end of the Proterozoic Eon, to the present. The Phanerozoic, the eon of visible life, is divided into three major eras: the Paleozoic, Mesozoic, and Cenozoic. Although life originated in Precambrian time, it was in the Phanerozoic that many forms arose and evolved. The Earth gradually assumed its present configuration and physical features through such processes as plate tectonics, mountain building, and glacia¬ tion.

pharaoh \'fer-o\ Epithet applied to Egyptian kings from c. 1500 to 343 bc. The term later evolved into a generic term for all ancient Egyptian kings. Pharaohs were regarded as gods, retaining their divine status even after death. A pharaoh’s will was supreme, and he governed by royal decree, with the assistance of viziers. The common people nevertheless judged a pharaoh by his deeds; many were criticized, plotted against, and even deposed and killed. See also Akhenaton; Amenemhet I; Amenhotep II; Amenhotep III; Ramses II; Thutmose III; Tutankhamen.

Pharisee \'far-3-,se\ Member of a Jewish religious party in Palestine that emerged c. 160 bc in opposition to the Sadducees. The Pharisees held that the Jewish oral tradition was as valid as the Torah. They struggled to democratize the Jewish religion, arguing that the worship of God was not confined to the Temple of Jerusalem and fostering the synagogue as an institution of worship. Their belief that reason must be applied in the interpretation of the Torah and its application to contemporary problems is now basic to Jewish theology.

pharmaceutical industry Producers of pharmaceuticals, substances used in the diagnosis, treatment, and prevention of disease and the modi¬ fication of organic functions. The earliest records of medicinal plants and minerals are those of the ancient Chinese, Hindu, and Mediterranean civi¬ lizations. Medicines were prepared first by physicians and later by apoth¬ ecary shops. The modern pharmaceutical industry began in the 19th century with the discovery of highly active medicinal compounds that could be manufactured most efficiently on a large scale. As these drugs replaced the herbal medicines of earlier times, the occurrence and sever¬ ity of such diseases as rheumatic fever, typhoid fever, pneumonia, polio¬ myelitis, syphilis, and tuberculosis were greatly reduced. Many drugs are extracted from plant substances; alkaloids such as quinine, cocaine, and morphine are among the best-known examples. Others are made from animal substances, such as the glandular extracts that are used to produce insulin. Pharmaceutical industry research has greatly aided medical progress, and many new drugs have been discovered and produced in industrial laboratories. Increasing health-care costs, government regula¬ tion, and research ethics are all issues of concern to the industry.

pharmacology V.far-mo-'kal-o-jeV Branch of medicine dealing with the actions of drugs in the body—both therapeutic and toxic effects—and development and testing of new drugs and new uses of existing ones. Though the first Western pharmacological treatise (a listing of herbal plants) was compiled in the 1st century ad, scientific pharmacology was possible only from the 18th century on, when drugs could be purified and standardized. Pharmacologists develop drugs from plant and animal sources and create synthetic versions of these, along with new drugs based on them or their chemical structure. They also test drugs, first in vitro (in the laboratory) for biochemical activity and then in vivo (on animals, human volunteers, and patients) for safety, effectiveness, side effects, and

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pharmacy ► phenylketonuria I 1485

interactions with other drugs and to find the best dose, timing, and route (mouth, injection, etc.). Drug products are constantly tested for potency and purity. See also drug poisoning; pharmacy; pharmaceutical industry.

pharmacy Science dealing with collection, preparation, and standard¬ ization of drugs. Pharmacists, who must earn a qualifying degree, prepare and dispense prescribed medications. They formerly mixed and measured drug products from raw materials according to doctors’ prescriptions, and they are still responsible for formulating, storing, and providing correct dosages of medicines, now usually produced by pharmaceutical compa¬ nies as premeasured tablets or capsules. They also advise patients on the use of both prescription and over-the-counter drugs. Laws regulating the pharmaceutical industry are based on the national pharmacopoeia, which outlines the purity and dosages of numerous medicinal products.

Pharsalus \far-'sa-bs\, Battle of (48 bc) Decisive engagement in the Roman civil war between Julius Caesar and Pompey. Caesar had recently been defeated by Pompey when the two met again in Greece. Though Pompey had twice as many men, Caesar used unorthodox tactics to over¬ whelm him. Pompey fled and about half his men surrendered; the rest were killed or took flight.

pharyngitis \,far-3n-'jl-bs\ Inflammation and infection (usually bacte¬ rial or viral) of the pharynx. Symptoms include pain (sore throat, worse on swallowing), redness, swollen lymph nodes, and fever. Throat culture may be the only way to distinguish infection with streptococcus bacteria (strep throat), which can cause rheumatic fever if not treated in time with antibiotics, from viral infections, which do not respond to antibiotics and require only symptom relief.

pharynx Vfar-iqksV Inside of the throat, from the oral and nasal cavi¬ ties (see mouth, nose) to the trachea and esophagus. It has three connected sections: the nasopharynx, at the back of the nasal cavity; the oropharynx, in the back of the oral cavity down to the epiglottis (a flap of tissue that closes off the larynx during swallowing); and the laryngopharynx, from the epiglottis to the esophagus. The oropharynx contains the palatine ton¬ sils. The eustachian tubes connect the middle ears to the pharynx, allow¬ ing air pressure on the eardrum to be equalized. Disorders include pharyngitis, tonsillitis, and cancer.

phase In thermodynamics, a chemically and physically uniform quantity of matter that can be separated mechanically from a nonhomogeneous mixture. It may consist of a single substance or of a mixture of substances. The three basic phases of matter are solid, liquid, and gas; other phases that are considered to exist include crystalline (see crystal), colloidal (see colloid), glass, amorphous, and plasma. The different phases of a pure sub¬ stance are related to each other in terms of temperature and pressure. For example, if the temperature of a solid is raised enough, or the pressure is reduced enough, it will become a liquid.

phase In wave motion, the fraction of the time required to complete a full cycle that a point completes after last passing through the reference position. Two periodic motions are said to be in phase when correspond¬ ing points of each reach maximum or minimum displacements at the same time. If the crests of two waves pass the same point at the same time, they are in phase for that position. If the crest of one and the trough of the other pass the same point at the same time, the phase angles differ by 180° and the waves are said to be of opposite phase. Phase differences are important in alternating electric current technology (see alternating CURRENT).

Phazania See Fezzan

pheasant Any of about 50 specie family Phasianidae (order Galli- formes), chiefly Asian but natural¬ ized elsewhere. Most species inhabit open woodlands and brushy fields.

All have a hoarse call. The feet and lower legs are unfeathered. Females are inconspicuous. Most males are strikingly coloured and have one or more leg spurs, and some have a fleshy facial ornament. Males some¬ times fight to the death for a harem of hens. Male ring-necked or com¬ mon pheasants {Phcisianus colchi- cus), 35 in. (90 cm) long, have a

streaming tail, coppery breast, purplish green neck, and ear tufts; they are widespread in the northern U.S. Japanese green pheasants (P versicolor ) call in concert when an earthquake is imminent.

Pheidias See Phidias

phenol Vfe-.nol, 'fe-.nolV Any of a class of organic compounds with a hydroxyl group (-OH; see functional group) attached to a carbon atom in a ring of an aromatic compound. The simplest one, carbolic acid (C 6 H 5 OH), is also called phenol; its most important reaction is with formaldehyde, with which it forms widely used polymers called phenol-formaldehyde (phe¬ nolic) resins. Phenols are similar to alcohols but form stronger hydrogen bonds (see bonding), so they dissolve more readily in water and boil at higher temperatures. They may be colourless liquids or white solids; many have a sharp, spicy odour. Some are found in essential oils. Phenols with higher molecular weights and phenol derivatives have supplanted phenol itself as industrial antiseptics (germicidal cleaners). See also Leo Baekeland.

phenol See carbolic acid

phenomenalism View that statements about material objects are reducible to statements about actual and possible sensations, or sense-data. According to phenomenalists, a material object is not a mysterious some¬ thing “behind” the appearances presented in sensation. If it were, the material world would be unknowable; indeed, the term matter is unintel¬ ligible unless it somehow can be defined by reference to sensations. In speaking about a material object, then, reference must be made to a very large system of possible sense-data, only some of which (if any) are ever actualized. Thus the statement “There is a fire in the next room” would be analyzed as a series of hypothetical statements such as “If one were to enter the next room with one’s eyes open, one would see a bright light of a yellowish orange colour.” Some philosophers have objected that it is difficult to remove all references to material objects from the hypotheti¬ cal statements to which material-object talk is supposedly reducible. See also George Berkeley.

phenomenology Philosophical discipline originated by Edmund Hus¬ serl. Husserl developed the phenomenological method to make possible “a descriptive account of the essential structures of the directly given.” Phenomenology emphasizes the immediacy of experience, the attempt to isolate it and set it off from all assumptions of existence or causal influ¬ ence and lay bare its essential structure. Phenomenology restricts the phi¬ losopher’s attention to the pure data of consciousness, uncontaminated by metaphysical theories or scientific assumptions. Husserl’s concept of the life-world—as the individual’s personal world as directly experienced— expressed this same idea of immediacy. With the appearance of the Annual for Philosophical and Phenomenological Research (1913-30), under Husserl’s editorship, his personal philosophizing flowered into an inter¬ national movement. Its most notable adherents were Max Scheler and Mar¬ tin Heidegger.

phenotype Vfe-n9-,tlp\ All the observable characteristics of an organ¬ ism, such as shape, size, colour, and behaviour, that result from the inter¬ action of its genotype (total genetic makeup) with the environment. The phenotype may change throughout the life of an individual because of environmental changes and the changes associated with aging. Different environments can influence the development of inherited traits (e.g., size is affected by available food supply) and can alter expression by similar genotypes (e.g., twins brought up in dissimilar families may mature dif¬ ferently). Furthermore, not all inherited possibilities in the genotype are expressed in the phenotype, because some are the result of inactive, reces¬ sive, or inhibited genes. See also variation.

phenylalanine V.fe-ffl-'a-b-.nen, ,fe-n 3 l-'a-b- l nen\ One of the essen¬ tial amino acids, present in many common proteins, especially hemoglobin. It is used in medicine and nutrition and as one of the two amino acids making up aspartame. Persons with phenylketonuria do not metabolize phe¬ nylalanine properly and must adhere to a diet free of it.

phenylketonuria \ 1 fe-n 3 l- I ke-t 3 n- , ur-e-o\ (PKU) or phenylpyru- vic oligophrenia \ l fe-n 3 l-pI- l rii-vik- l al-i-go- , fre-ne-3\ Inability to nor¬ mally metabolize phenylalanine, the accumulation of which interferes with normal childhood development. Central nervous system effects include mental retardation and seizures (see epilepsy), with behavioral signs seen at four to six months of age. Abnormal metabolism also leads to low mela¬ nin levels, with light hair, eye, and skin colour. Tests detect this recessive genetic disorder (see congenital disorder; recessiveness) in two-thirds of the 1 in 10,000 newborns born with high levels of phenylalanine. Keeping

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1486 I pheromone ► Philip

phenylalanine out of the diet (by total avoidance of meat, dairy, and high- protein foods and aspartame) until adolescence permits normal develop¬ ment. Protein is supplied in a phenylalanine-free formula. Pregnant women with PKU must resume the diet to prevent severe damage to the unborn child.

pheromone \'fer-3- l mon\ Any chemical compound secreted by an organism in minute amounts to elicit a particular reaction from other organ¬ isms of the same species. Pheromones are widespread among insects and vertebrates (except birds) and are present in some fungi, slime molds, and algae. The chemicals may be secreted by special glands or incorporated into other substances (e.g., urine), shed freely, or deposited in selected loca¬ tions. Pheromones are used to bring creatures together (e.g., in termite, bee, and ant colonies), lead them to food (e.g., in scent trails laid by ants), signal danger (e.g., when released by wounded fish to alert others), attract a mate and elicit sexual behaviour (numerous examples, possibly including humans), and influence sexual development (in many mammals and certain insects). Alarm pheromones often last a shorter time and travel a shorter distance than other types. In vertebrates, chemical stimuli often influence parent-young responses. Sex-attractant pheromones are used in certain products to lure and trap unwanted or harmful insects.

Phi Beta Kappa Leading academic honour society in the U.S., which draws its membership from college and university students. The oldest Greek-letter society in the U.S., it was founded in 1776 as a secret liter¬ ary and philosophical society at the College of William and Mary. It became an honour society in the 19th century. Membership is now based on general scholarship, and new members are usually elected by Phi Beta Kappa faculty.

Phibunsongkhram Vpe-bun-soq-.krairA, Luang orig. Plaek Khit- tasangkha (b. July 14, 1897, near Bangkok, Siam—d. June 12, 1964, Tokyo, Japan) Field marshal and premier of Thailand (1938-44, 1948- 57). After military training in France, he helped organize the Promoters Revolution of 1932, which ended absolute monarchy in what was then Siam; in 1939 he changed the country’s name to Thailand. As premier during World War II, he allied himself with Japan, but, as the war turned against Japan, his government collapsed. The army seized power in 1947, and he was reinstalled as premier in 1948. Opposed to communism, he further allied Thailand to the West during the Cold War by helping estab¬ lish the Southeast Asia Treaty Organization. He was ousted by his military colleagues in 1957 and fled to Japan.

Phidias \'fid-e-os\ or Pheidias \'fi-de-9s\ (fl. c. 490^130 bc, Athens, Greece) Greek sculptor. Placed in charge of the great building program initiated by Pericles in Athens, he supervised and probably designed the overall sculptural decoration of the Parthenon. He also created its most important religious images, including the colossal statue of the Athena Parthenos (438-436 bc).

Many of the Parthenon’s sculptures (the Elgin Marbles) are now in the British Museum. Ancient writers considered his masterpiece to be the statue of Zeus (c. 430 bc) for the Temple of Zeus at Olympia. He ini¬ tiated the idealistic Classical style that distinguishes Greek art in the later 5 th and 4th centuries bc.

Philadelphia City (pop., 2000: 1,517,550) and port, southeastern Penn¬ sylvania, U.S., at the confluence of the Delaware and Schuylkill rivers. The site was occupied by the Delaware Indians before William Penn founded the city in 1682. It was the capital of Pennsylvania 1683-1799 and the capital of the U.S. between 1790 and 1800. It played a prominent role in opposing British policies and was the site of the first and second Continental Con¬ gresses, the signing of the Declaration of Independence, and the Constitu¬ tional Convention. The population grew in the 18th century, with many immigrants from Scotland, Ireland, and Germany. It was the largest and most important city of the U.S. in the 19th century and a centre of the anti¬ slavery movement. In 1876 it was the site of the U.S. Centennial Exposi¬ tion. It is also the site of the U.S.’s oldest art museum (the Pennsylvania Academy of the Fine Arts, founded in 1805) and the first U.S. hospital (the

Pennsylvania Hospital, founded in 1751). It is the largest city in the state and a centre of commerce, finance, industry, and culture. Its numerous edu¬ cational institutions include the University of Pennsylvania.

Philadelphia Inquirer Morning newspaper, long one of the most influential dailies in the eastern U.S. Founded in 1847 as the Pennsylva¬ nia Inquirer , it took its present name c. 1860. It was a strong supporter of the Union in the American Civil War. In the 19th and early 20th cen¬ turies it survived circulation wars by providing broad news coverage and by constantly modernizing its plant and equipment. Bought by Moses Annenberg in 1936, it stayed in his family’s hands until 1969, when it was acquired by John S. Knight. In 1974 it became part of the merged Knight-Ridder Newspapers group.

Philae \'fi-le\ Former island of the Nile River in Upper Egypt. It was sacred to Isis and contained many temples, the earliest dating from the 7th century bc. After the completion of the Aswan High Dam in 1970, the temples were moved to the nearby island of Agilkia before Philae was submerged by the waters of Lake Nasser.

philanthropy Voluntary, organized efforts intended for socially useful purposes. Philanthropic groups existed in the ancient civilizations of the Middle East, Greece, and Rome: an endowment supported Plato’s Acad¬ emy (c. 387 bc) for some 900 years; the Islamic waqf (religious endow¬ ment) dates to the 7th century ad; and the medieval Christian church administered trusts for benevolent purposes. Merchants in 17th- and 18th- century western Europe founded organizations for worthy causes. Start¬ ing in the late 19th century, large personal fortunes led to the creation of private foundations that bequeathed gifts totaling millions and then bil¬ lions in support of the arts, education, medical research, public policy, social services, environmental causes, and other special interests. See Andrew Carnegie; B'nai B'rith; Bill Gates; George Peabody; Rockefeller Foundation; Straus family.

Philaretus See Arnold Geulincx

philately \fo-Ta-t 3 l-e\ Collection and study of postage stamps. The first postage stamps were issued in England in 1840, and in the U.S. in 1842. Stamp collectors usually spe¬ cialize, collecting stamps of one country, one period of time, or one subject (e.g., birds, flowers, art).

Value depends on rarity and condi¬ tion. An issue of stamps that includes a printer’s error may have increased value.

Philby, Kim orig. Harold Adrian Russell (b. Jan. 1, 1912,

Ambala, India—d. May 11, 1988,

Moscow, Russia, U.S.S.R.) British intelligence officer and Soviet spy.

He became a communist at the Uni¬ versity of Cambridge in the 1930s, and in 1933 he became a Soviet agent. Recruited into the MI-6 section of British intelligence by Guy Burgess (1940), he became head of counterespionage operations. In 1949 he was sent to Washington, D.C., as top liaison officer between British and U.S. intelligence services. He revealed top-secret information to the Soviets and in 1951 warned Burgess and Donald Maclean (1913-83) that they were under suspicion, enabling them to escape. Philby himself came under suspicion and was dismissed from MI-6 in 1955. He worked as a jour¬ nalist in Beirut, then in 1963 he fled to the Soviet Union, where he worked for the KGB and rose to the rank of colonel. The most successful Soviet double agent of the Cold War period, he was responsible for the deaths of many Western agents.

Philemon and Baucis \fi-Te-m3n...'b6-sis\ In Greek mythology, a pious old couple in Phrygia. When Zeus and Hermes, disguised as wayfar¬ ers, had been turned away by the couple’s richer neighbors, Philemon and Baucis extended them hospitality. As a reward they were spared when a flood swept the countryside. Their cottage was turned into a temple, and they became priest and priestess of it. Years later they were granted their wish to die at the same moment, and they were turned into trees.

Philip (of Swabia) German Philipp (b. 1178—d. June 21, 1208, Bamberg, Ger.) German Hohenstaufen king (1198-1208). The youngest son of Frederick I Barbarossa, he was elected German king on the death

"Heracles/' marble statue produced in the workshop of Phidias, from the east¬ ern pediment of the Parthenon, the Acropolis, Athens, c. 5th century bc; in the British Museum

COURTESY OF THE TRUSTEES OF THE BRITISH MUSEUM; PHOTOGRAPH, J.R. FREEMAN & CO. LTD.

© 2006 Encyclopaedia Britannica, Inc.

Philip II ► Philip VI I 1487

of Emperor Henry VI. The rival Welf dynasty elected Otto IV king, and a civil war broke out. A truce was finally called in 1207; Innocent III rec¬ ognized Philip and promised to crown him emperor (1208), but Philip was murdered first.

Philip II or Philip of Macedon (b. 382—d. 336 bc, Asia Minor) Eighteenth king of Macedonia (359-336), father of Alexander the Great. Appointed regent for his nephew, he seized the throne. He initially pro¬ moted peace with his neighbours, using the time gained thereby to build his forces and introducing innovations in arms, tactics, and training and stabilizing his western frontier. His movements on the eastern frontier provoked the Greeks into forming a coalition against him. He intervened in the Sacred War to free Delphi from the Phocians, becoming the ally of Thebes and the Thessalian League, whose president he became. Demos¬ thenes turned Athens against him with his Philippics (346-342), and Thebes also came to view Philip as a threat. He defeated both at the Battle of Chaeronea, becoming leader of all Greece. He formed the Greek states into the League of Corinth to attack Persia but was undone by family politics. After he took a second wife, his first wife, Olympias, left him, taking Alexander. Philip was assassinated by a Macedonian nobleman, possibly in collusion with Olympias and Alexander.

Philip II French Philippe known as Philip the Bold (b. Jan. 17, 1342, Pontoise, France—d. April 27, 1404, Halle, Brabant) Duke of Bur¬ gundy (1363-1404). He was granted the duchy of Burgundy by his father, John II, and by marriage and purchase he acquired additional lands in northern and central France, Flanders, and the Netherlands. He shared the government with his brothers during the minority of his nephew Charles VI, ensuring friendly relations with England and Germany. When Charles went insane (1392), Philip became virtual ruler of France. He formed an alliance with England (1396) and withdrew his support of the Avignon papacy (1398).

Philip II French Philippe known as Philip Augustus (b. Aug. 21, 1165, Paris—d. July 14, 1223, Mantes) French king (1179-1223). The first of the great Capetian kings, he gradually reconquered the French territories held by the kings of England. He joined with Richard I on the Third Crusade, but the two kings soon quarreled. Philip returned to France (1191) and attacked English possessions; imprisoned in Austria on his journey home, Richard was freed in 1194 and promptly went to war with the French. When Richard was killed (1199), his brother John signed a treaty with Philip (1200), but within two years France and England were again at war. Philip conquered Normandy (1204) and subdued Maine, Touraine, Anjou, and most of Poitou (1204-05). John later organized a coalition against France, but he was defeated by Philip at the Battle of Bouvines (1214). Philip also expanded his territory into Flanders and Languedoc.

Philip II Spanish Felipe \fa-'le-pa\ (b. May 21, 1527, Valladolid, Spain—d. Sept. 13, 1598, El Esco- rial) King of Spain (1556-98) and of Portugal (as Philip I, 1580-98). The son of Emperor Charles V, Philip received from his father the duchy of Milan (1540), the kingdoms of Naples and Sicily (1554), the Neth¬ erlands (1555), and Spain and its overseas empire (1556). He ruled from the Netherlands from 1555 and waged a successful war against France in 1557. From 1559 he ruled from Spain, where he built the pal¬ ace of El Escorial and encouraged Spain’s literary golden age. He was a champion of the Counter- Reformation but failed to put down rebellions in the Netherlands (from 1568) and to conquer England, suf¬ fering the defeat of the Spanish Armada (1588). He gained a victory in the Mediterranean with the defeat of the Ottoman offensive at the Battle of Lepanto (1571) and unified the Iberian Peninsula as king of Portugal from 1580. During his reign the Spanish empire attained its greatest power, extent, and influence.

Philip III French Philippe known as Philip the Good (b. July 31, 1396, Dijon, Burgundy—-d. June 15, 1467, Bruges) Duke of Burgundy

(1419-67). The most important of the Valois dukes of Burgundy, he founded the Burgundian state that rivaled France in the 15th century. He confirmed his right to Burgundy by signing the Treaty of Troyes with Henry V of England (1420), and he maintained an alliance with England, breaking it only during his unsuccessful attempt to capture Calais (1435— 39). Philip avoided conflict with France and instead attacked his smaller neighbors, conquering Hainaut, Brabant, Holland and Zeeland, and Lux¬ embourg by 1443. A renowned patron of the arts, he presided over one of Europe’s most extravagant courts.

Philip III Spanish Felipe (b. April 14, 1578, Madrid, Spain—d. March 31, 1621, Madrid) King of Spain and of Portugal (1598-1621). The son of Philip II, he was an indifferent ruler and allowed royal favourites to gov¬ ern in his place. From 1609 his government continued the policy of expel¬ ling the Moriscos (Christians of Moorish ancestry), which caused serious economic problems. The huge sums he spent on court entertainments exacerbated Spain’s growing economic problems.

Philip IV French Philippe known as Philip the Fair (b. 1268, Fon¬ tainebleau, France—d. Nov. 29, 1314, Fontainebleau) King of France (1285-1314). On inheriting the French throne, he modeled himself on his grandfather, Louis IX. He was also king of Navarre (as Philip I, 1284- 1305), ruling jointly with his wife, Joan I of Navarre. War with England (1294-1303) ended with a peace treaty and the betrothal of his daughter to the future Edward II. Philip forced a harsh treaty on Flanders in 1305. He conducted a long struggle with Boniface VIII (1297-1303) that led to the breakdown of the medieval papacy. He was pacified by succeeding popes, including Clement V, who began the Avignon papacy. Philip expelled the Jews from France (1306), and his persecution of the Knights Templar in 1307 led to their suppression by the pope four years later.

Philip IV Spanish Felipe (b. April 8, 1605, Valladolid, Spain—d. Sept. 17, 1665, Madrid) King of Spain (1621-65) and of Portugal (as Philip II, 1621-40). He succeeded his father, Philip III. and left the administration of his rule to his chief ministers, the duke de Olivares (1621-43) and the duke’s nephew Luis Mendez de Haro (1643-61). Spain’s industry and commerce declined, and wars against Holland, France, and Germany fur¬ ther drained Spain’s economy. Portugal regained its independence (1640), and Holland was lost by the Peace of Westphalia (1648). A poet and patron of the arts, Philip was the friend and frequent subject of Diego VelAzquez.

Philip V (b. 238—d. 179 bc, Amphipolis, Macedonia) King of Mace¬ donia (221-179). Son of Demetrius II, he succeeded Antigonus Doson. He supported the Hellenic League against Sparta, Aetolia, and Elis (220- 217), allying himself with Hannibal in 215 and attacking Roman client states in Illyria. Rome responded in the First Macedonian War. Intrigue against Egypt and Philip’s unsuccessful sea battle with Rhodes and Per- gamum led Rome to initiate the Second Macedonian War, in which it pre¬ vailed at Cynoscephalae (197). Rome’s harsh terms eased after Philip made common cause against its Greek foes. Fearing that Rome would turn on him again, he attempted to expand by attacking the Balkans (184, 183, 181); he died on a fourth attempt in 179.

Philip V Spanish Felipe orig. Philippe, duke d'Anjou (b. Dec. 19, 1683, Versailles, France—d. July 9, 1746, Madrid, Spain) King of Spain (1700-46). Grandson of Louis XIV of France and great-grandson of Philip IV of Spain, Philip was named to succeed the childless Charles II as king in 1700. Louis’s refusal to exclude Philip from the line of succes¬ sion to the French throne led to the War of the Spanish Succession. The resultant Peace of Utrecht (1713) deprived Philip of the Spanish Nether¬ lands and parts of Italy, but it left him Spain and Spanish America. Ini¬ tially influenced by his French advisers through his wife, Maria Luise of Savoy, after her death (1714) he was influenced by his second wife, Eliza¬ beth Farnese, and her Italian advisers. Attempts to secure territories in Italy caused the formation of the Quadruple Alliance (1718) against Spain. Philip later brought Spain into the War of the Austrian Succession. His reign marked the beginning of the Bourbon dynasty in Spain (see house of Bourbon).

Philip VI or Philip of Valois \val-'wa\ French Philippe de Valois

(b. 1293—d. Aug. 22, 1350, near Paris) First French king of the Valois dynasty (1328-50). He continued Capetian efforts to centralize the state but made concessions to the nobility, clergy, and bourgeoisie. His knights killed thousands of rebellious Flemings at the Battle of Cassel (1328). His disputes with Edward III of England led to the outbreak of the Hundred Years' War (1337). French defeats at the Battles of Sluys (1340) and Crecy

Philip II, detail of an oil painting by Titian; in the Corsini Gallery, Rome.

AUNARI/ART RESOURCE, NEW YORK

© 2006 Encyclopaedia Britannica, Inc.

1488 I Philip ► Philippines

(1346) caused crises in France until the spread of the Black Death (from 1348) overshadowed other considerations.

Philip, duke of Edinburgh known as Prince Philip (b. June 10, 1921, Corfu, Greece) Husband of Queen Elizabeth II of Britain. Son of Prince Andrew of Greece and Denmark (1882-1944) and Princess Alice (1885-1969), a great-granddaughter of Queen Victoria, he was reared in Britain. In World War II he served in combat with the Royal Navy. In 1947 he became a British subject, taking his mother’s surname. Mount- batten, and renouncing his right to the Greek and Danish thrones. He married Princess Elizabeth in 1947 and continued on active service in the navy until her accession to the throne in 1952. Charles, prince of Wales, is their son.

Philip, King See Metacom Philip Augustus See Philip II (France)

Philip Morris tobacco companies Two of the world’s largest tobacco companies, comprising Philip Morris International Inc. and Philip Morris USA Inc., both of which are owned by U.S. holding company Altria Group, Inc. Drawing on the name of Philip Morris, a London tobacconist who opened shop in the mid 1800s, the company was incorporated in New York in 1902 as a British-American venture; ownership shifted to Ameri¬ can stockholders in 1919, when the company was renamed Philip Morris & Co. It became a principal maker of cigarettes in the 1930s and ’40s, and the popularity of its Marlboro cigarettes grew with its use of cowboy imagery to advertise them in the mid 1950s. The company developed other American cigarette brands such as Parliament, Virginia Slims, and Merit. Overseas ventures in the manufacture and marketing of cigarettes led to the formation of Philip Morris International, which by 1972 had estab¬ lished sales in many parts of the world, including the former Soviet Union. Its global brands include Chesterfield and Lark.

Philip of Hesse (b. Nov. 13,1504, Marburg, Hesse—d. March 31,1567, Kassel, Ger.) German nobleman, landgrave of Hesse, and champion of the Reformation. His skillful management made Hesse a sovereign state. Won to the cause of Martin Luther, Philip became a Reformation leader in Ger¬ many. In 1529 he founded the first Protestant university at Marburg (1529), and in 1531 he united several princes and towns to form the Schmalkaldic League. However, his folly in contracting a bigamous second marriage dam¬ aged his reputation. After the emperor crushed the league, Philip was imprisoned (1547-52). Long imprisonment undermined his influence and his health, though he finally saw Lutheranism gain a position of legal equal¬ ity with Catholicism in the Peace of Augsburg (1555). In the year of his death, he divided Hesse among his four sons.

Philip of Macedonia See Philip II Philip of Valois See Philip VI (France)

Philip the Bold See Philip II (Burgundy)

Philip the Fair See Philip IV (France)

Philip the Good See Philip ill (Burgundy)

Philipon \fe-le-'po n \, Charles (b. April 19, 1802, Lyon, France—d. Jan. 25, 1862, Paris) French caricaturist, lithographer, and journalist. An excellent draftsman with a fertile sense of satire and vigorous political opinions, he published a series of journals of political satire. La Carica¬ ture, which he introduced in 1830, was suppressed in 1835; Le Charivari, introduced in 1832, became the inspiration for Punch, subtitled The Lon¬ don Charivari. His drawing showing the transformation of Louis- Philippe into the shape of a pear established the pear as the common symbol for the king. He attracted and inspired the best caricaturists in France, includ¬ ing Honore Daumier and Gustave Dore.

Philippe Egalite See due d’ Orleans

Philippi \'fi-b-,pl\ Ruined hill town, northern central Macedonia, Greece. In c. 357 bc it was fortified by King Philip II to control nearby gold mines. In 42 bc it was the scene of the decisive Roman battle in which Mark Antony and Octavian (later Augustus) defeated Brutus and Cassius, the leading assassins of Julius Caesar. Many Christian ruins, especially of the 5th-6th century ad, are spread over the site. St. Paul preached the gospel to Christian converts there.

Philippine-American War or Philippine Insurrection (1899- 1902) War between the U.S. and Filipino revolutionaries, which may be seen as a continuation of the Philippine Revolution against Spanish rule. The

Treaty of Paris (1898), which concluded the Spanish-American War, trans¬ ferred Philippine sovereignty from Spain to the U.S.; but it was not rec¬ ognized by Filipino leaders, whose troops controlled the entire archipelago except the capital city of Manila. By 1902 U.S. troops had defeated the insurgency, though sporadic fighting continued until 1906. The U.S. retained possession of the islands (except for the Japanese occu¬ pation during World War II) until 1946.