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.