Page:The American Cyclopædia (1879) Volume XII.djvu/782

 768 OXLEE salts. Thus when sulphuric oxide (anhydrous sulphuric acid, S0 3 ) is passed in a state _ of vapor over oxide of barium, BaO, combination takes place with evolution of heat and light, and sulphate of barium is formed containing all the elements of the original bodies (BaO + S0 3 =BaSO 4 or BaO, S0 3 ). There is an inter- mediate group of oxides, called neutral oxides, because of their indifference to entering into combinations. The black oxide, binoxide or dioxide of manganese, MnOa, is an example of this group, the monoxide of the same inetal being basic and the higher oxides acid. The dioxide of lead (peroxide) may also be classed with these ; for although it possesses feeble acid properties, and plumbates of the alkalies may be formed, they are decomposed by solution in water. Moreover, the dioxide of lead in the presence of acids is generally decomposed, with the formation of a salt of the monoxide. The three groups are not separated by very decided lines, although the well marked types are characteristic. They blend together upon their borders by imperceptible degrees, so that the same oxide will exhibit basic reactions toward one body, while it behaves like an acid toward another. In general it may be said that when oxygen combines in several propor- tions with a metallic element, the lower oxides are basic, while the higher ones have an acid character. OXLEE, John, an English clergyman, born Sept. 25, 1779, died Jan. 30, 1854. He was rector of Scawton, Yorkshire, from 1816 to 1826, and of Molesworth, Hants, from 1836. He devoted much time to the study of orien- tal languages, and published several theologi- cal works, the most important of which are : "Christian Doctrine of the Trinity and In- carnation " (3 vols. 8vo, 1815-'50) ; " Sermons on the Christian Hierarchy;" and "Letters on the Conversion of the Jews " (1843). OXLIP. See PKIMKOSE. OXPECKER, a bird of the starling family, and the genus lupJiaga (Linn.), inhabiting the Oxpecker (Buphaga Africana). warm parts of Africa; it is also called "beef- eater. ' The bill is pincer-like, stout and broad at the base, with depressed culmen and curved oxus tip ; the wings long and pointed, the first quill very short and the third the longest ; the tail long, broad, and wedge-shaped, with the end of each feather pointed ; tarsi and toes robust, and the claws compressed, curved, and sharp. The best known species, B. Africana (Linn.), is between 8 and 9 in. long, reddish brown above and yellowish white below ; the bill is yellowish, with a red tip. It is shy, generally seen in flocks of seven or eight, about herds of cattle, alighting on their backs and extracting the larvae of the hot flies (cestridce) which in- fest them ; the bulging of the bill at the end is admirably adapted for gently squeezing out these and other parasites from under the skin, which form their chief food. Another spe- cies, B. erythrorJiyncha (Stanl.), has a red bill. OXUS, the classical and still common name of the Amoo Darya or Jihoon, an important river of western Asia. It has its source about 15,600 ft. above the sea, in the Sir-i-Kol (Lake Sir), or Lake Victoria, in the district of Pamir, and on the recently defined boundary between Afghanistan and eastern Turkistan ; flows in a generally W. direction, forming the northern Afghan boundary, as far as the post of Khodja Salah; then takes a N". W. course through Bokhara and Khiva, and falls through several mouths into the sea of Aral. Its length is be- tween 1,200 and 1,300 m. For about 300 m. of the first part of its course it is called the Panja ; and in this distance it receives five im- portant and a great number of smaller afflu- ents, draining E. Bokhara and N. E. Afghan- istan. Below the most westerly of these five affluents, the Koksha river, the main stream receives the name of Amoo Darya ; and from this point to its mouth it is navigable, but flows through the almost completely desert waste of Khiva. Its delta is low and marshy, and several of its mouths are so shallow as to be impassable even for small craft. The great- est breadth of the main channel of the stream is about 3,200 ft. ; its greatest depth a little more than 5 fathoms. The valley of the river, and especially that of the upper Oxus, has long been one of the most interesting regions for geographers and ethnologists ; for the lat- ter, because of the common hypothesis which regards the region about its source as the cradle of the human race; and for the former, on account of the interesting explorations made during recent years, and the theories and dis- coveries with regard to the ancient and mod- ern beds of the river. It seems conclusively established that the Oxus at one time, through a course still clearly traceable, flowed into the Caspian sea. The peculiar features of the whole Khivan region, supposed to have once formed the bed of an inland sea, add to the interest of the Oxus valley. The Oxus has been important in political history. Alexander's eastern campaigns brought him several times to its banks ; and its valley was the scene of important events in later times. Recently it has been brought prominently into discussion