Blok, Aleksandr (Aleksandrovich) (b. Nov. 28, 1880, St. Peters¬ burg, Russia—d. Aug. 7, 1921, Petrograd [St. Petersburg]) Russian poet and dramatist. He was the principal representative of Russian Symbolism
(see Symbolist movement). He later rejected what he termed their sterile bourgeois intellectualism and embraced the Bolshevik movement as essential for the redemption of the Russian people. Influenced by early 19th-century Romantic poetry, he wrote musical verse in which sound was paramount. His preeminent work of impressionistic verse was the enig¬ matic ballad The Twelve (1918), which united the Russian Revolution and Christianity in an apocalyptic vision. In the era of postrevolutionary hard¬ ship he declined into mental and physical illness, possibly brought on by venereal disease, and died at 40.
Blondin \blo n -'da n ,\ English \'blan-den\ orig. Jean-Francois Grav- elet (b. Feb. 28, 1824 , Hesdin, Fr.—d. Feb. 22, 1897, Little Ealing, near London, Eng.) French tightrope walker. After training as an acrobat, he achieved fame, first in 1859, with his many crossings of Niagara Falls on a tightrope 1,100 ft (335 m) long, 160 ft (48 m) above the water. Each time he used a different theatrical variation: blindfolded, in a sack, trun¬ dling a wheelbarrow, on stilts, carrying a man on his back, and sitting down midway to cook an omelette. He gave his last performance in 1896.
blood Circulatory fluid (see circulation) in multicellular animals. In many species it also carries hormones and disease-fighting substances. Blood picks up oxygen from the lungs and nutrients from the gastrointes¬ tinal tract and carries them to cells throughout the body for metabolism. It picks up carbon dioxide and other wastes from those cells and transports them to the lungs and excretory organs. Blood composition varies among species. Mammalian blood consists of plasma, red and white cells (eryth¬ rocytes and leukocytes), and platelets (thrombocytes). Blood disorders include polycythemia (abnormal increase in the number of circulating red blood cells), anemia, leukemia, and hemophilia. See also ABO blood-group system; blood analysis; blood bank; blood pressure; blood transfusion; blood typing; Rh blood-group system.
blood analysis Laboratory examination of the physical and chemical properties and components of a sample of blood. Analysis includes num¬ ber of red and white blood cells (erythrocytes and leukocytes); red cell vol¬ ume, sedimentation (settling) rate, and hemoglobin concentration; blood typing; cell shape and structure; hemoglobin and other protein structure; enzyme activity; and chemistry. Special tests detect substances character¬ istic of specific infections.
blood bank Organization that collects, stores, processes, and supplies blood. Most blood donations are separated into components, which can be frozen and stored longer than whole blood and used by multiple patients. In hemapheresis, large amounts of one component can be sepa¬ rated from a single donor’s blood and the rest returned to the donor. Before World War I, a physician had to find a compatible donor and give an immediate blood transfusion. Safe storage of blood and its components made possible innovations such as heart-lung machines.
blood poisoning See septicemia
blood pressure Force originating when the heart’s pumping pushes the blood against the walls of the blood vessels. Their stretching and con¬ traction help maintain blood flow. Usually measured over an arm or leg artery in humans, blood pressure is expressed as two numbers; normal adult blood pressure is about 120/80 mm of mercury. The higher number (systolic) is measured when the heart’s ventricles contract and the lower (diastolic) when they relax. See also hypertension, hypotension.
blood transfusion Transfer of blood taken from one person into the circulation of another to restore blood volume, increase hemoglobin lev¬ els, or combat shock. Once the blood-group antigens and antibodies (see ABO blood-group system, Rh blood-group system) were discovered, BLOOD typing of donors and recipients rendered transfusion safe. In exchange transfusion, all or most of the blood is removed and replaced with anoth¬ er’s blood. Undesirable reactions to transfusion are not uncommon.
blood typing Classification of blood by inherited antigens associated with erythrocytes (red blood cells). The ABO blood-group system and Rh blood-group system are among those most commonly considered. Without identification of these factors, blood transfusion from an incompatible donor may result in destruction of red cells or coagulation. Blood typing also helps identify disorders such as erythroblastosis fetalis.
bloodhound Breed of dog superior to any other in scenting ability, the foundation breed of most scent-hunting hound breeds. They were known, although not in the present form, in the Mediterranean area in pre- Christian times. Calm and affectionate, they are often used to track ani-
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Bloodless Revolution ► Bliicher I 235
mals and trail persons. A large, strong dog, the bloodhound stands 23-27 in. (58-69 cm) and weighs 80-110 lb (35-50 kg). It has short hair and long ears, with loose skin that falls into folds and wrinkles around the head and neck. The coat is black-and-tan, red-brown and tan, or tawny.
Bloodless Revolution See Glorious Revolution
bloodroot Plant ( Sanguinaria canadensis ) of the poppy family, native throughout eastern and midwestern North America, growing mainly in deciduous woodlands and blooming in early spring. The white, cup¬ shaped flower with bright yellow sta¬ mens in the centre is borne on a reddish stalk. Large, veiny, half- opened leaves on red stalks enfold the flower stem and, after the flower has bloomed, open into multilobed, round, blue-green leaves. The orange-red sap, once used by Ameri¬ can Indians for dye, is found in the rhizomes, as is the medical alkaloid sanguinarine. The species, particu¬ larly the variety S. canadensis ‘Mul¬ tiplex,’ which has showy double flowers, is an interesting plant for the wild garden.
Bloody Sunday (1905) Massacre of peaceful demonstrators in Saint Petersburg, marking the beginning of the Russian Revolution of 1905. The priest Georgy Gapon (1870-1906), hoping to present workers’ request for reforms directly to Nicholas II, arranged a peaceful march toward the Winter Palace. Police fired on the demonstrators, killing more than 100 and wounding several hundred more. The massacre was followed by strikes in other cities, peasant uprisings, and mutinies in the armed forces. The term “Bloody Sunday” was also used to describe the murder in Dub¬ lin, Ireland (Nov. 21, 1920), of 11 Englishmen suspected of being intel¬ ligence agents, by the Irish Republican Army; the Black and Tans took revenge and attacked spectators at a football (soccer) match, killing 12 and wounding 60. The term was used again in Londonderry (Derry) when on Jan. 30, 1972, 3 participants in a civil rights march were killed by British soldiers, who allegedly had been fired on by the marchers.
Bloom, Harold (b. July 11, 1930, New York, N.Y., U.S.) U.S. literary critic. Bloom studied at Cornell and Yale universities and taught at Yale from 1955. In The Anxiety of Influence (1973) and A Map of Misreading (1975) he suggested that poetry results from poets deliberately misread¬ ing the works that both influence and threaten them. In The Book of J (1990) he speculated that the earliest known biblical texts were written by a woman with principally literary intentions. His best-selling The West¬ ern Canon (1994) identifies 26 canonical Western writers and argues against the politicization of literary study.