AVEBBHOA 361 AVICENNIA the entrance of hell, by which Ulysses and iEneas descended into the lower re- gions. In the time of Vergil, a com- munication between it and the neighbor- ing Lucrine Lake was made by Agrippa ; but in 1538, the latter was filled by a volcanic eruption, when Monte Nuovo rose in its place, rendering the Averno again a separate lake. On its banks, in- stead of pestilential marshes, are now beautiful gardens and vineyards. Here was placed the grave of Hecate, and the grotto of the Cumaean sibyl is still to be seen here. AVERRHOA (av-er-ho'a), a genus of plants, order oxalidacese. It consists of two species, both of which form small trees in the East Indies. They are re- markable for their leaves, which are pin- nated, possessing, in a slight degree, the kind of irritability found in the sensi- tive plant; and for their fleshy oval fruits with five thick longitudinal wings. In the carambola (A. aciambola) , the leaves are smooth, the flowers of a violet purple, and the fruit about the size of a goose's egg; it is of a pale yellow color, and is said to be agreeably acid in the East Indies. The other species, called the blimbing (A. blimbi) , has downy leaves and fruit resembling the small cucumber. The latter is intensely acid and cannot be eaten raw. It is pickled and candied, or a syrup is ob- tained from it by boiling with sugar, and its juice is found an excellent agent for rempving iron mold or other spots from linen. To the Malays it answers the same purposes as the citron, the gooseberry, the caper and the cucumber of Europe. AVERROES (av-er-6'az), or AVERR- HOES (corrupted from Ebn or Ibn RosHD or Rushd), an Arabian philoso- pher and physician, born 1120. He suc- ceeded his father in the chief magistracy of Cordoba, capital of the Moorish do- minions in Spain; was afterward nomi- nated chief judge in Morocco, and, hav- ing there appointed deputies to his office, he returned to Spain. The liberality of his opinions, however, caused him to be persecuted by the more orthodox Mos- lems, and he was imprisoned; but, after doing penance and making recantation, he was liberated. Averroes greatly ad- mired Aristotle, and his commentaries on the writings of that philosopher procured for him the title of "The Commentator." Of the personal character of Averroes almost nothing is known. Like every Mohammedan, he cultivated jurispru- dence; and, like every distinguished Arabian, he was devoted to poetry. He died at Morocco in 1198. AVERY, SAMUEL, an American ed- ucator, born in Lamoille, 111., in 1865. He graduated from Doane College in 1887. He took special courses in science at the University of Nebraska, and studied also at Heidelberg University, iieceiving the degree of Ph. D. in 1896. He was adjunct professor of chemistry at the University of Nebraska from 1896 to 1899, professor of chemistry and chemist at the Agricultural Experimen- tal Station at the University of Idaho from 1899 to 1901, then returned to the University of Nebraska, and in 1905 was appointed chief professor of chemistry at that institution. During 1908 to 1909 he was appointed acting chancellor, and in the latter year chancellor of the Uni- versity of Nebraska. He was a member of many scientific societies, the author of several reports on chemical subjects, a popular lecturer on educational topics, and was a member of the International Conciliation Commission with Sweden in 1914 and 1915. AVESTA. See Zend Avesta. AVEYRON (a-va-ron), a department occupying the S. extremity of the cen- tral plateau of France, traversed by mountains belonging to the Cevennes and the Cantal ranges; principal rivers: Aveyron, Lot and Tarn, the Lot alone being navigable. The climate is cold, and agriculture is in a backward state, but considerable attention is paid to sheep breeding. It is noted for its Roquefort cheese. It has coal, iron, and copper mines, besides other minerals. Area, 3,340 square miles; capital, Rhodez. Pop. about 370,000. AVIARY, a building or inclosure for keeping, breeding and rearing birds. Aviaries appear to have been used by the Persians, Greeks, and Romans, and are highly prized in China. In England they were in use at least as early as 1577, when William Harrison refers to "our costlie and curious aviaries." An aviary may be simply a kind of very large cage; but the term usually has a wider scope than this. AVICENNIA, or WHITE MAN- GROVE, a genus of verbenaceas, consists of trees or large shrubs resembling man- groves, and, like them, growing in tidal estuaries and salt marshes. Their creep- ing roots, often standing six feet above the mud in crowded pyramidal masses^ and the naked asparagus-like suckers which they throw up, have a singular ap- pearance. The bark of A. tomentosa, the white mangrove of Brazil, is much used for tanning. A green, resinous sub- stance exuding from A. resinifera is eaten by the New Zealanders. The
