Skip this Advertisement

A-Z Browse

  • Adoptionist Monarchianism (heresy)
    Agobard wrote against the Adoptionist heresy (that Jesus was not the son of God by nature but by adoption) of Felix of Urgel (who was confined at Lyon from 800 to 818), against contemporary superstitions, and against the Jews. His zeal for reform led him to attack trial by ordeal and image worship and, more generally, to promote the unity of the Carolingian empire and its legal system....
  • adoptive parent (kinship)
    the act of establishing a person as parent to one who is not in fact or in law his child. Adoption is so widely recognized that it can be characterized as an almost worldwide institution with historical roots traceable to antiquity....
  • adoration (religion)
    ...by Christian church authorities, who interpreted a sentence as a slighting reference to Jesus and so ordered its deletion. Reform Judaism uses a modified form of the ʿalenu that is called Adoration in the ritual. In Gates of Prayer: The New Union Prayer Book (1975), however, Reform worshipers were given the option of using the original concept of the ʿalenu in...
  • “Adoration, L’ ” (work by Borel)
    ...and a visiting professor at various colleges and universities in the United States (1966–83). His principal novel, L’Adoration (1965; “The Adoration”; Eng. trans. The Bond), which won the Prix Goncourt, was a semiautobiographical account of a son’s relationship to a widowed mother and had Proustian or Joycean characteristics in presenting vast de...
  • Adoration of the Holy Eucharist (painting by Coello)
    Coello’s masterwork is the altarpiece for the sacristy in El Escorial, “Adoration of the Holy Eucharist” (1685–90). A fine arrangement of space in the Baroque style, it contains about 50 portraits, including that of Charles II. A remarkable mixture of profound religious feeling and realistic portraiture, closely allied to the work of Velázquez and Carreño,...
  • Adoration of the Kings (painting by Veronese)
    The nocturnal tone in the Adoration of the Kings in the church of Sta. Corona (Vicenza) endows the painting with a new intimacy, without renunciation of the characteristic Veronesian richness of colour, laid on with the minute, precious brushstrokes also used in small canvases, both sacred and profane, executed during this period. These paintings represent the most......
  • Adoration of the Kings (painting by Gossart)
    ...most likely to be identified with Jennyn van Hennegouwe, who is registered as a master in the Guild of St. Luke at Antwerp in 1503. His most important early work extant is the Adoration of the Kings, which is painted in the ornate style of the Antwerp school. Other early works, such as Jesus, the Virgin, and the Baptist, reflect his......
  • “Adoration of the Lamb” (work by Hubert and Jan van Eyck)
    ...of oil painting. His naturalistic panel paintings, mostly portraits and religious subjects, made extensive use of disguised religious symbols. His masterpiece is the altarpiece in the cathedral at Ghent, the Adoration of the Lamb (also called Ghent Altarpiece, 1432). Hubert van Eyck is thought by some to have been Jan’s brother....
  • Adoration of the Magi (religious motif)
    The Adoration of the Magi—i.e., their homage to the infant Jesus—early became one of the most popular themes in Christian art, the first extant painting on the subject being the fresco in the Priscilla Catacomb of Rome dating from the 2nd century. In the Middle Ages the Adoration of the Magi was often associated with two other major events of Jesus’ life: his Baptism, during w...
  • Adoration of the Magi (painting by Leonardo da Vinci)
    ...used chiaroscuro effects, but in European painting the technique was first brought to its full potential by Leonardo da Vinci in the late 15th century in such paintings as his Adoration of the Magi (1481). Thereafter, chiaroscuro became a primary technique for many painters, and by the late 17th century the term was routinely used to describe any painting, drawing,.....
  • Adoration of the Magi (sculpture by Lewis)
    ...The Death of Cleopatra was exhibited at the Philadelphia Centennial Exposition. In 1883 she received her last major commission, a version of the Adoration of the Magi, from a church in Baltimore, Maryland. This piece, like the bulk of her work, cannot be located and perhaps did not survive. It was variously reported that Lewis had been...
  • Adoration of the Magi, The (painting by Giotto di Bondone)
    Giotto was named after the 14th-century Italian painter Giotto di Bondone, whose 1305–06 fresco The Adoration of the Magi includes a realistic depiction of a comet as the Star of Bethlehem in the Nativity scene; this image is believed to have been inspired by the artist’s observation of the passage of Halley’s Comet in 1301....
  • Adoration of the Magi, The (painting by Poussin)
    ...in the style of an ancient relief. The order and complexity of this new style led Poussin increasingly to rely on making detailed preparatory drawings for his pictures. The Adoration of the Magi of 1633 serves as a manifesto of his artistic conversion and is unashamedly modelled after an earlier work on this theme by the greatest Classical master of the......
  • adoration of the shepherds (religious motif)
    as a theme in Christian art, depiction of shepherds paying homage to the newborn Christ, an event described in the Gospel According to Luke. It is related to the older but less frequently represented annunciation to the shepherds, which shows the same shepherds in the fields receiving from an angel news of the miraculous birth....
  • Adoration of the Trinity by Pope Clement, The (fresco by Tiepolo)
    ...by now contending for his work and where he was being praised as “the most famous of the virtuosi.” Rather, he preferred to send his works abroad, as in the case of The Adoration of the Trinity by Pope Clement (c. 1735), which was sent to Nymphenburg and is now in the Alte Pinakothek in Munich, or The Martyrdom of St.......
  • Adoration with St. Francis and St. Lawrence (painting by Caravaggio)
    ...painted The Resurrection of Lazarus and The Adoration of the Shepherds. Then he moved on to Palermo, where he did the Adoration with St. Francis and St. Lawrence for the Oratorio di San Lorenzo. The works of Caravaggio’s flight, painted under the most adverse of circumstances, show a subdued tone and a...
  • “Adornment of the Spiritual Marriage, The” (work by Ruysbroeck)
    ...systematic compendium of teaching and belief, however, contrasted with the more introspective nature of Meister Eckehart’s writings. Die Chierheit der gheesteliker Brulocht (1350; The Spiritual Espousals), considered to be his masterpiece, develops his view of the Trinity and is a guide for the soul in search of God. Though his many writings were produced for his......
  • Adorno family (ruling family of Genoa)
    Genoese family prominent in the politics of that city’s “popular” (democratic) dogeship (1339–1528), when the old aristocracy was exiled and new families seized power. Branches of the family became prominent in Flanders and Spain....
  • Adorno, Theodor Wiesengrund (German philosopher and music critic)
    German philosopher who also wrote on sociology, psychology, and musicology....
  • Adoula, Cyrille (prime minister of Democratic Republic of the Congo)
    ...bastion of secessionism, the pro-Lumumba Stanleyville government, to be brought to heel. Meanwhile, following the convening of parliament in Léopoldville, a new civilian government headed by Cyrille Adoula came to power on August 2, 1961....
  • Adour River (river, France)
    river in southwestern France. The Adour River rises in the central Pyrenees near Tourmalet Pass, just south of Midi de Bigorre Peak, and flows in a curve, north, then west, to enter the Bay of Biscay just below Bayonne after a course of 208 miles (335 km). Draining a basin of 5,800 square miles (15,000 square km), it traverses the scenic Campan Valley and, after passing Bagnères-de-Bigorre...
  • Adowa (Ethiopia)
    town, northern Ethiopia. Adwa lies on the east-west highway between Aksum and Adi Grat at its junction with the road north to Asmara (Asmera), in Eritrea. Adwa is a market centre (grains, honey, hides, coffee) for the Tigray people. The town is located 10 miles (16 km) west of an area of fantastic volcanic formations. On March 1, 1896, Emperor Menilek II defeated an Italian force there. Nearby are...
  • Adowa, Battle of (Italy-Ethiopia [1896])
    (March 1, 1896), military clash at Adwa, in north-central Ethiopia, between the Ethiopian army of King Menilek II and Italian forces. The decisive Ethiopian victory checked Italy’s attempt to build an empire in Africa....
  • Adoxa moschatellina (plant)
    Adoxa moschatellina (muskroot) is widely distributed in northern regions. It is a low-growing perennial herb composed of a basal cluster of leaves and a single stem. It has a musky odour (as its name implies), and its cultivation is limited to rock gardens....
  • Adoxaceae (plant)
    Adoxaceae used to include only the herbaceous genera Adoxa and Sinadoxa, but two more genera, Viburnum (175 species) and Sambucus (elderberry, 9 species), were added under APG II. These latter genera are found mostly in the northern temperate zone, but Viburnum also grows on some tropical mountains....
  • ADP (American company)
    ...continuous production throughout the war. In 1943, under the leadership of the aircraft engineer and designer Clarence L. (“Kelly”) Johnson, Lockheed established a highly secret section, Advanced Development Projects (ADP), to design a fighter around a British De Havilland jet engine. The result was the P-80 Shooting Star, the first American jet aircraft to enter operational servi...
  • ADP (coenzyme)
    Adenosine monophosphate, diphosphate, and triphosphate (AMP, ADP, and ATP, respectively) are important participants in energy processes in the living cell. Each of the compounds is composed of the nucleotide base adenine linked to the sugar ribose, which in turn is linked to a linear “tail” of one, two, or three phosphate groups, respectively, as shown....
  • Adrano (Italy)
    town, eastern Sicily, Italy. It lies near the Simeto River on a lava plateau on the western slopes of Mount Etna, northwest of Catania city. It originated as the ancient town of Hadranon, founded about 400 bc by Dionysius I, tyrant of Syracuse, near a sanctuary dedicated to the Siculan god Adranus (Hadranus). Conquered in 263 bc by ...
  • Adranum (Italy)
    town, eastern Sicily, Italy. It lies near the Simeto River on a lava plateau on the western slopes of Mount Etna, northwest of Catania city. It originated as the ancient town of Hadranon, founded about 400 bc by Dionysius I, tyrant of Syracuse, near a sanctuary dedicated to the Siculan god Adranus (Hadranus). Conquered in 263 bc by ...
  • Adrar (region, Mauritania)
    traditional region of central Mauritania in western Africa. It consists of a low central massif with noticeable cliffs that rise to about 800 feet (240 m). The terrain is arid and almost totally unsuitable for cropping. There is, however, sufficient water at the base of the uplands to support date-palm groves, and during the wetter part of the year there is cultivation of millet, sorghum, melons,...
  • Adrar (oasis, Algeria)
    palm grove settlement, the largest of the Touat oasis group, southwestern Algeria, in the Sahara. Adrar’s historical name was given it by the local Berber people, the Timmi, who established their ksar (fortified village) here. The modern name is derived from the Berber adrar (“mountain”). The settlement lies between the Erg (sand dunes) Chech a...
  • Adrar des Iforas (plateau, Mali)
    Northern and central Mali are made up of the plains of the Niger River basin and of the Sahara. The only marked relief feature in the north is the Iforas Massif. An extension of the mountainous Hoggar region of the Sahara, this heavily eroded sandstone plateau rises to elevations of more than 2,000 feet....
  • Adrastus (Greek mythology)
    ...on which of them was to succeed to the Theban throne and decided to rule in alternate years. As Eteocles’ turn came first, Polyneices withdrew to Argos, where he married Argeia, daughter of King Adrastus. Another daughter, Deipyle, married Tydeus, son of the exiled king Oeneus of Calydon. At the end of the year, Polyneices’ turn came to rule Thebes. When Eteocles refused to give u...
  • adrenal cortex (anatomy)
    The adrenal cortex...
  • adrenal cortical insufficiency (pathology)
    rare disorder defined by destruction of the outer layer of the adrenal glands, the hormone-producing organs located just above the kidneys....
  • adrenal corticosteroid (chemical compound)
    any of a group of more than 40 organic compounds belonging to the steroid family and present in the cortex of the adrenal glands. Of these substances, about six are hormones, secreted into the bloodstream and carried to other tissues, where they elicit physiological responses. (The other corticoids, inactive as hormones, appear to be intermediates in the biosynthesis of the hormones from choleste...
  • adrenal crisis (pathology)
    The symptoms of adrenal insufficiency increase in intensity over time and eventually (after several months) lead to acute adrenal insufficiency, known as adrenal crisis. Adrenal crisis is characterized by fever, vomiting, diarrhea, and a precipitous fall in blood pressure. The patient may go into shock and die unless he or she is treated vigorously with an intravenous saline solution and with......
  • adrenal gland
    either of two small triangular endocrine glands that are located above each kidney. In humans each adrenal gland weighs about 5 grams (about 0.18 ounce) and measures about 30 mm (1.2 inches) wide, 50 mm (2 inches) long, and 10 mm (0.4 inch) thick. Each gland consists of two parts: an inner medulla, which produces epinephrine and norepinephrine...
  • adrenal hormone
    ...lactation in women is inferred from the results of studies done on animals and from clinical observations that are in agreement with the results of animal studies. Prolactin, growth hormone, and adrenal hormone seem of greatest value in restoring lactation after removal of the pituitary, although the precise response varies from species to species....
  • adrenal medulla (anatomy)
    The adrenal medulla...
  • adrenal steroid (chemical compound)
    any of a group of more than 40 organic compounds belonging to the steroid family and present in the cortex of the adrenal glands. Of these substances, about six are hormones, secreted into the bloodstream and carried to other tissues, where they elicit physiological responses. (The other corticoids, inactive as hormones, appear to be intermediates in the biosynthesis of the hormones from choleste...
  • adrenal tumour (pathology)
    ...hyperfunction may be congenital or acquired. Congenital hyperfunction is always due to hyperplasia (enlargement) of both adrenal glands, whereas acquired hyperfunction may be due to either an adrenal tumour or hyperplasia. Congenital adrenal hyperplasia, also known as the adrenogenital syndrome, is a disorder in which there is an inherited defect in one of the enzymes needed for the......
  • adrenaline (hormone)
    two separate but related hormones secreted by the medulla of the adrenal glands. They are also produced at the ends of sympathetic nerve fibres, where they serve as chemical mediators for conveying the nerve impulses to effector organs. Chemically, the two compounds differ only slightly; and they exert similar pharmacological actions, which resemble the effects of stimulation o...
  • adrenergic drug
    any of various drugs that interfere with the functioning of the sympathetic nervous system by affecting the release or action of norepinephrine and epinephrine. The former are hormones, secreted by the adrenal gland, that constrict blood vessels (thus increasing blood pressure) and accelerate the rate and force of contractions of the heart....
  • adrenergic nerve fibre (anatomy)
    nerve fibre that releases the neurotransmitter norepinephrine (also known as noradrenaline) at the synapse, or junction, between a nerve and its end organ, which may be a muscle, gland, or another nerve. Adrenergic nerve fibres make up the sympathetic nervous system, one of two peripheral nervous systems controlling involu...
  • adrenergic receptor (biology)
    Receptors sensitive to norepinephrine and epinephrine are called adrenergic receptors. They are divided into two types, α and β. These are further classified into subtypes α1, α2, β1, and β2....
  • adrenoceptor (biology)
    Receptors sensitive to norepinephrine and epinephrine are called adrenergic receptors. They are divided into two types, α and β. These are further classified into subtypes α1, α2, β1, and β2....
  • adrenocortical hyperactivity (pathology)
    Adrenocortical hyperfunction may be congenital or acquired. Congenital hyperfunction is always due to hyperplasia (enlargement) of both adrenal glands, whereas acquired hyperfunction may be due to either an adrenal tumour or hyperplasia. Congenital adrenal hyperplasia, also known as the adrenogenital syndrome, is a disorder in which there is an......
  • adrenocortical hyperfunction (pathology)
    Adrenocortical hyperfunction may be congenital or acquired. Congenital hyperfunction is always due to hyperplasia (enlargement) of both adrenal glands, whereas acquired hyperfunction may be due to either an adrenal tumour or hyperplasia. Congenital adrenal hyperplasia, also known as the adrenogenital syndrome, is a disorder in which there is an......
  • adrenocortical hypofunction (pathology)
    rare disorder defined by destruction of the outer layer of the adrenal glands, the hormone-producing organs located just above the kidneys....
  • adrenocorticosteroid (chemical compound)
    any of a group of more than 40 organic compounds belonging to the steroid family and present in the cortex of the adrenal glands. Of these substances, about six are hormones, secreted into the bloodstream and carried to other tissues, where they elicit physiological responses. (The other corticoids, inactive as hormones, appear to be intermediates in the biosynthesis of the hormones from choleste...
  • adrenocorticotropic hormone
    a polypeptide hormone formed in the pituitary gland that regulates the activity of the outer region (cortex) of the adrenal glands. In mammals the action of ACTH is limited to those areas of the adrenal cortex in which the glucocorticoid hormones—cortisol and corticosterone (see corticoid)—are formed. The secretion of ACTH by the pituitary is itself regulate...
  • adrenocorticotropin
    a polypeptide hormone formed in the pituitary gland that regulates the activity of the outer region (cortex) of the adrenal glands. In mammals the action of ACTH is limited to those areas of the adrenal cortex in which the glucocorticoid hormones—cortisol and corticosterone (see corticoid)—are formed. The secretion of ACTH by the pituitary is itself regulate...
  • adrenogenital syndrome (pathology)
    enlargement of the adrenal glands resulting primarily from excessive secretion of androgenic hormones by the adrenal cortex. Congenital adrenal hyperplasia mainly affects infants and is caused by mutations in the genes for enzymes that catalyze the production of cortisol by the adrenal...
  • Adret, Rabbi Shlomo ben Abraham (Spanish rabbi)
    outstanding spiritual leader of Spanish Jewry of his time (known as El Rab de España [the Rabbi of Spain]); he is remembered partly for his controversial decree of 1305 threatening to excommunicate all Jews less than 25 years old (except medical students) who studied philosophy or science....
  • Adret, Solomon ben Abraham (Spanish rabbi)
    outstanding spiritual leader of Spanish Jewry of his time (known as El Rab de España [the Rabbi of Spain]); he is remembered partly for his controversial decree of 1305 threatening to excommunicate all Jews less than 25 years old (except medical students) who studied philosophy or science....
  • Adrets, François de Beaumont, baron des (French military leader)
    French military leader of the Wars of Religion, notorious for his cruelty....
  • Adria (Italy)
    town and episcopal see in the Veneto regione of northern Italy, on the Bianco Canal just east of Rovigo. Founded by the Etruscans or the Veneti of northeastern Italy, it later became a Roman town and was a flourishing port on the Adriatic Sea (to which it gave its name) until the silting up of the Po and Adige deltas caused the sea (now 13.5 miles [22 km] east) to recede ...
  • Adriamandisoarivo (African ruler)
    The other son, Adriamandisoarivo, continued the migration northward and established his rule over a second Sakalava kingdom, Boina. At his death about 1710, Boina covered the broad coastal plain between the Manambalo and Mahajamba rivers and collected tribute from neighbouring states. Some disintegration followed his death, but Boina regained its cohesion under Queen Ravahiny (d. 1808). It......
  • Adrian (Roman emperor)
    Roman emperor (ad 117–138), the emperor Trajan’s nephew and successor, who was a cultivated admirer of Greek civilization and who unified and consolidated Rome’s vast empire....
  • Adrian (Michigan, United States)
    city, seat (1838) of Lenawee county, southeastern Michigan, U.S., on the River Raisin, 40 miles (65 km) southwest of Ann Arbor. Addison J. Comstock settled the site in 1826 as Logan and renamed it in 1828 for the Roman emperor Hadrian (the H was dropped in 1838). With his father, Darius, Comstock built the Erie and Kalamazoo Railroad ...
  • Adrian (English abbot)
    Appointed by Pope St. Vitalian, Theodore was consecrated in 668 and then set out from Rome with SS. Adrian, abbot of Nerida, Italy, and Benedict Biscop, later abbot of Wearmouth and Jarrow, Durham. In 669 they reached Canterbury, where Theodore made Adrian the abbot of SS. Peter and Paul monastery, afterward named St. Augustine’s. There they created a famous school influential in the lives ...
  • Adrian I (pope)
    pope from 772 to 795 whose close relationship with the emperor Charlemagne symbolized the medieval ideal of union of church and state in a united Christendom....
  • Adrian II (pope)
    pope from 867 to 872....
  • Adrian III, Saint (pope)
    pope from 884 to 885....
  • Adrian IV (pope)
    the only Englishman to occupy the papal throne (1154–59)....
  • Adrian of Cambridge, Edgar Douglas Adrian, 1st Baron (British electrophysiologist)
    British electrophysiologist who with Sir Charles Sherrington won the Nobel Prize for Physiology or Medicine in 1932 for discoveries regarding the nerve cell....
  • Adrian of Utrecht (pope)
    the only Dutch pope, elected in 1522. He was the last non-Italian pope until the election of John Paul II in 1978....
  • Adrian V (pope)
    pope for about five weeks in 1276....
  • Adrian VI (pope)
    the only Dutch pope, elected in 1522. He was the last non-Italian pope until the election of John Paul II in 1978....
  • Adriana, Villa (villa, Tivoli, Italy)
    country residence built (c. ad 125–134) at Tivoli near Rome by the emperor Hadrian. This villa is considered the epitome in architecture of the opulence and elegance of the Roman world. Covering approximately 7 square miles (18 square km), the complex was more an imperial garden city than a traditional villa. Its buildings were designed to follow the ...
  • Adrianople (Turkey)
    city, extreme western Turkey. It lies at the junction of the Tunca and Maritsa (Turkish: Meriç) rivers near the borders of Greece and Bulgaria. The largest and oldest part of the town occupies a meander of the Tunca around the ruins of an ancient citadel. Edirne’s site and turbulent history were determined by its strategic position on the main route from Asia Minor...
  • Adrianople, Battle of (ancient Rome)
    (Aug. 9, ad 378), battle fought at present Edirne, in European Turkey, resulting in the defeat of a Roman army commanded by the emperor Valens at the hands of the Germanic Visigoths led by Fritigern and augmented by Ostrogothic and other reinforcements. It was a major victory of barbarian horsemen over Roman infantry and marked the beginning of serious Germanic inr...
  • Adrianople, Peace of (1878)
    ...the Russian lines of communication in Armenia were ill-prepared, and the Turks were able to support an attempt by Circassian exiles to reoccupy their homeland. But this failed, and, by the Peace of Adrianople, Russia succeeded in adding to its Transcaucasian territories the districts of Kars, Batumi, and Ardahan....
  • Adrianople, Peace of (1829)
    (Sept. 14, 1829), pact concluding the Russo-Turkish War of 1828–29, signed at Edirne (ancient Adrianople), Tur.; it strengthened the Russian position in eastern Europe and weakened that of the Ottoman Empire. The treaty foreshadowed the Ottoman Empire’s future dependence on the European balance of power and also presaged the eventual dismembermen...
  • Adrianople, Peace of (1713)
    ...light terms from the inept Turkish negotiators, who allowed him to retire with no greater sacrifice than the retrocession of Azov. The Turkish government soon decided to renew hostilities; but the Peace of Adrianople (Edirne) was concluded in 1713, leaving Azov to the Turks. From that time on Peter’s military effort was concentrated on winning his war against Sweden....
  • Adrianople, Treaty of (1190)
    ...was passing through Byzantine territory. Isaac tried to protect himself by concluding a treaty with Saladin, the sultan of Egypt, but he was soon forced to assist Frederick; Isaac concluded the Treaty of Adrianople with him in February 1190, and in the following month Frederick’s forces were transported across the Hellespont to Asia Minor....
  • Adrianople, Treaty of (1829)
    (Sept. 14, 1829), pact concluding the Russo-Turkish War of 1828–29, signed at Edirne (ancient Adrianople), Tur.; it strengthened the Russian position in eastern Europe and weakened that of the Ottoman Empire. The treaty foreshadowed the Ottoman Empire’s future dependence on the European balance of power and also presaged the eventual dismembermen...
  • Adriatic Karst (geological region, southeastern Europe)
    ...These are closed depressions with flat and alluviated bottoms that may be as much as 60 kilometres in diameter. Many of these depressions are elongate parallel to the geologic structure and to the Adriatic coastline. Although isolated poljes have been identified elsewhere, their large numbers in the karst of the Dinaric Alps are attributable to a system of active faults as well as to intense......
  • Adriatic Sea (sea, Mediterranean Sea)
    arm of the Mediterranean Sea, lying between the Italian and Balkan peninsulas. The Strait of Otranto at its southeasterly limit links it with the Ionian Sea. It is about 500 mi (800 km) long with an average width of 100 mi, a maximum depth of 4,035 ft (1,324 m), and an area of 50,590 sq mi (131,050 sq km). The Adriatic has been of great importance in the historical development of Mediterranean Eur...
  • Adrien de Gerlache (Belgian naval officer)
    Belgian naval officer who led the first Antarctic expedition concentrating on scientific observation (1897–99). Sailing with him as mate on the Belgica was Roald Amundsen, who on a subsequent expedition of his own was the first to reach the South Pole....
  • Adrienne Lecouvreur (work by Scribe)
    ...as Le Verre d’eau (1840; “The Glass of Water”), which derives great historical events from a trivial incident, and Bertrand et Raton (1833), a historical comedy. His Adrienne Lecouvreur (1849), a melodrama about an actress who loves a nobleman, unaware of his high rank and true identity, was favoured as a vehicle by such notable actresses as Sarah Bernh...
  • Adroa (African deity)
    ...by rainmakers and the heads of large family groups. Government-appointed chiefs are set over large areas. The majority of Lugbara still practice ancestor worship; they believe in a creator god, Adroa. They are one of the peoples least affected by modern changes in Uganda, maintaining a strong sense of their own identity....
  • Adroqué, Esteban (Argentine politician)
    ...(province). The county was founded in 1873, and the county seat is often referred to as Adroqué, the name of its founder, and its railroad station bears that name. Esteban Adroqué petitioned the provincial government to expropriate land from the existing counties of San Vicente and Quilmes to establish the new one. The original settlers were residents of......
  • adṛṣṭa (Indian philosophy)
    ...organ, or an object. Chapter 5 deals with the notion of action and the connected concept of effort, and the next traces various special phenomena of nature to the supersensible force, called adṛṣṭa. Chapter 6 argues that performance of Vedic injunctions generates this supersensible force and that the merits and demerits accumulated lead to......
  • ADSL modem (telecommunications)
    ...subscriber and the central office (the local loop). These new technologies include high data rate subscriber lines (HDSL), which allow bidirectional data rates of up to 750 kilobits per second, and asymmetric digital subscriber lines (ADSL), which permit half-duplex data transmission at rates up to 6.144 megabits (million bits) per second. Because these last two technologies apply only to......
  • Adso of Montier-en-Der (Benedictine monk and abbot)
    Benedictine monk and abbot whose treatise on the Antichrist became the standard work on the subject from the mid-10th to the 13th century....
  • adsorbed atom (chemistry)
    ...of the discharged ions into the crystal lattice, are separated in time and space, an intermediate species exists at the surface, that of relatively loosely bound and freely moving atoms, called adatoms. Since the electrons tend to join the rest in the bulk of the metal, adatoms appear to have a partial charge, less than that of the elementary positive charge. The adatoms therefore attract......
  • adsorption (surface phenomenon)
    capability of all solid substances to attract to their surfaces molecules of gases or solutions with which they are in contact. Solids that are used to adsorb gases or dissolved substances are called adsorbents; the adsorbed molecules are usually referred to collectively as the adsorbate. An example of an excellent adsorbent is the charcoal used in gas masks to remove poisons or impurities from a...
  • adsorption and surface reaction (mechanism of adhesion)
    ...pores in the adherend surface or around projections on the surface. The second, interdiffusion, results when liquid adhesive dissolves and diffuses into adherend materials. In the third mechanism, adsorption and surface reaction, bonding occurs when adhesive molecules adsorb onto a solid surface and chemically react with it. Because of the chemical reaction, this process differs in some degree....
  • adsorption chromatography (chemistry)
    In adsorption chromatography solute molecules bond directly to the surface of the stationary phase. Stationary phases may contain a variety of adsorption sites differing in the tenacity with which they bind the molecules and in their relative abundance. The net effect determines the adsorbent activity. Partition chromatography utilizes a support material coated with a stationary-phase liquid.......
  • adsorption isotherm (chemistry)
    ...For a given species, the ratio of the times spent in the moving and stationary regions is equal to the ratio of its concentrations in these regions, known as the partition coefficient. (The term adsorption isotherm is often used when a solid phase is involved.) A mixture of solutes is introduced into the system in a confined region or narrow zone (the origin), whereupon the different species......
  • adsorption theory (technology)
    ...have been the object of physical and chemical study since at least the 1960s, with the result that a number of theories of adhesion exist. The main mechanism of adhesion is explained by the adsorption theory, which states that substances stick primarily because of intimate intermolecular contact. In adhesive joints this contact is attained by intermolecular or valence forces exerted by......
  • ADT (computing)
    Abstract data types (ADTs) are important for large-scale programming. They package data structures and operations on them, hiding internal details. For example, an ADT table provides insertion and lookup operations to users while keeping the underlying structure, whether an array, list, or binary tree, invisible. In object-oriented languages, classes are ADTs and objects are instances of them.......
  • ADT radar (radar technology)
    ...to enter a radar receiver and produce spurious responses. Well-trained operators are not often deceived by interference, though they may find it a nuisance. Interference is not as easily ignored by automatic detection and tracking systems, however, and so some method is usually needed to recognize and remove interference pulses before they enter the automatic detector and tracker of a radar....
  • Adu, Helen Folasade (British singer)
    The year 2001 witnessed the reunion of a beloved pop icon and an adoring fan base as Nigerian-born British singer Sade emerged from an almost decade-long hiatus to embark on a world tour with new material from her latest album, Lovers Rock (2000). The singer renowned for her sensual voice and exotic looks had lapsed into silence after the release in 1992 of the wildly successful Love Del...
  • Adua (Ethiopia)
    town, northern Ethiopia. Adwa lies on the east-west highway between Aksum and Adi Grat at its junction with the road north to Asmara (Asmera), in Eritrea. Adwa is a market centre (grains, honey, hides, coffee) for the Tigray people. The town is located 10 miles (16 km) west of an area of fantastic volcanic formations. On March 1, 1896, Emperor Menilek II defeated an Italian force there. Nearby are...
  • Adua (African dance)
    ...dance into an ecstatic trance in which they are caught and controlled by dance organizers. A more ordered line-and-soloist pattern is used by Asante women in the Kumasi district of Ghana in their Adua dance, which is notable for elaborating expressive hand movements into a language of gestures....
  • Adua, Battle of (Italy-Ethiopia [1896])
    (March 1, 1896), military clash at Adwa, in north-central Ethiopia, between the Ethiopian army of King Menilek II and Italian forces. The decisive Ethiopian victory checked Italy’s attempt to build an empire in Africa....
  • Aduatuca Tungrorum (Belgium)
    municipality, Limburg province, northeastern Belgium. It lies along the Geer (Jaar) River, northwest of Liège. Important in Roman times as Aduatuca Tungrorum, capital of the Germanic Tungri tribe, it was the centre of a revolt against Rome in 54 bc. Tongeren is the oldest city in Belgium and was the seat of a bishopric by the 4th century. In its stormy past it was sacke...
Skip this Advertisement

Link to this article and share the full text with the readers of your Web site or blog-post.

If you think a reference to this article on "" will enhance your Web site, blog-post, or any other web-content, then feel free to link to this article, and your readers will gain full access to the full article, even if they do not subscribe to our service.

You may want to use the HTML code fragment provided below.

copy link

We welcome your comments. Any revisions or updates suggested for this article will be reviewed by our editorial staff. Contact us here.

Regular users of Britannica may notice that this comments feature is less robust than in the past. This is only temporary, while we make the transition to a dramatically new and richer site. The functionality of the system will be restored soon.

The Britannica Store
A-Z Browse

Image preview