OPORTO
1387
ORACLE
and seems to destroy also the moral faculties. For the opium wars see CHINA. See Opium and the Opium Appetite by Calkin and Opium Smoking in America and China.
Oporto (o-por'tdo), the second city in Portugal, is situated on the Douro, three miles from the Atlantic. The city climbs the steep banks of the river, its houses, gayly painted, making a bright picture set off from the pine-covered mountains behind it. On one of the crags overlooking the river is a crystal palace surrounded with gardens. The old cathedral was built by Henry the Navigator; the Gothic church was founded in 559; and the former monasteries are used, one as a citadel, one as an exchange and one as barracks. There are a medical school (246 students), observatory, a fine art academy (133 students), library of 250,000 volumes and two picture galleries. The railroad to Lisbon crosses the river a little above the city on one of the finest arch bridges built. The manufactures are cloth, silk, hats, porcelain, ribbons, tobacco, soap and metal casting, distilling, cork-cutting and sugar-refining. It is the chief seat of the export trade in port wine, and in the vicinity, in 1900, were 15 cottonmills. Oporto was the stronghold of the Christians in the peninsula against the attacks of the Moors. The people in 1828 opposed the usurper, Miguel, who executed many of them; but they supported Pedro of Brazil, and withstood the besiegers thirteen months. Population 167,955.
Opos'sum, animal representing the mar-SUpials or pouched animals in the New
OPOSSUM
World. There are some 16 species, varying in size from a cat down to a mouse. Some are provided with pouches on the under side of the body in which the young are reared, and others have no sign of a pouch. In those forms without a pouch the young, when fully developed, are frequently carried on the back, with their tails twined round that of the mother. The Virginia opossum is common from the central United States to Brazil. It is one of the largest members of the group, being about the size of a cat. The
hair is long and coarse; black and white, giving the appearance of grayish-white, underneath the fur white and woolly; nose and lips white; ears erect, hairless, black tipped with white; tail prehensile, flesh-colored, almost bare. In general appearance the animal reminds one somewhat of a little pig. The Virginia opossum brings forth her young when they are very small, only about half an inch long; as soon as one is born the mother places it in her well-developed pouch, where it and its brothers and sisters are kept several weeks — sometimes there are a dozen to carry about and provide with milk. The little ones sleep and eat and grow. Perhaps by the time they are the size of rats and able to ride on her back there will be a second brood in the pouch. There are two or three litters a year. As great eaters, opossums may again be likened to the pig; they eat everything and anything: insects, wild fruit and berries, varied with roots, reptiles, crayfish, eggs, small rats and mice, with additions of poultry, corn, sweet potatoes and other farm-yard delicacies. As enemies of the destructive cotton-rat they are highly valued. They hunt mainly by night, sleep by day, live in trees. They are expert climbers; in going up a tree they use tail and hand-shaped feet very much as does a monkey. They dislike cold, seldom come forth when snow is on the ground, remaining in their dens for*^armth and comfort, having stored away fat for this time of need. The opossum's habit of feigning death when frightened or slightly injured is well-known, and in this he is a consummate actor — lies stretched out mo«-tionless, breathless, nose colorless, white lips apart and the teeth gleaming stark, death* like. See Stone and Cram! American Ani* mals; Hornaday: American Natural History.
Op'tics. See LIGHT, TELESCOPE, CAMERA, EYE, OPERA-GLASS, MICROSCOPE, PHYSICS.
Or'acle, in ancient times a revelation by some god in answer to questions, and also the place where the revelations were given. The revelations were usually made by the mouths of priests or priestesses, and sometimes by other signs. At Dodona the oracle answered by the motion of leaves or the murmuring of the waters of a fountain, and the oracle of Ammon responded by the shaking of the statue of the god. The Egyptian temples were nearly all oracles, and there were oracles among the Babylonians and Phoenicians. The most famous oracle of the Greeks was the one at Delphi. The inquirers offered sacrifices, walked around the oracle with laurel crowns on their heads, and inscribed their questions on leaden tablets, many of which have been discovered. The answer was accepted as final and having authority, and usually was just and reasonable. Other oracles were at Ismenus, Delos and Olympia. See Greek Oracles by P. W. H. Myers and Religious Antiquities by SohO-manns (translated).
