38 SILESIA and a fat, sensual face, always intoxicated, and either mounted upon an ass or carried by sa- tyrs In the contest with the giants Bacchus 2 assisted by Silenus, who slew Enceladus Silenus is also represented as an inspired prophet, and a sage who despised the gifts of fortune. Wln-n he was drunk and asleep, any one could compel him to prophesy by sur- rounding him with a garland or chain of flow- ers. There was a temple sacred to him at Elis. Several poems and works of plastic art introduced more than one Silenus at a time, representing the older satyrs. Ml FMA (Ger. Schletien), Austrian, a duchy comprising that part of Silesia which remained to the house of Austria after the peace of 1763, bounded by Prussian Silesia, Galicia, Hungary, and Moravia; area, 1,988 sq. m. ; pop. in 1874, , of whom about 14 per cent, were Prot- . 1 per cent. Jews, and the remainder Roman Catholics. Fully one half of the pop- ulation are Germans, 29 per cent. Poles, and over 19 per cent. Czechs. The Carpathian mountains pass through it in the. southeast, and the Moravian in the northwest, and it is watered by the upper Oder, the Vistula, which rises in the province, and other rivers. About one third of the territory is cohered with for- ests. It is one of the most important grazing provinces of Austria. The mining and weav- ing industries are important. Before 1849 it formed with Moravia a single administrative province, and then became a separate crown land under the name of the duchy of Upper and Lower Silesia. Until 1866 it was one of the 11 Austrian states belonging to the Ger- man confederation, and since 1867 it has been one of the 14 Cisleithan provinces represent- ed in the Reichsrath. The principal towns are Troppau, the capital, Teschen, Bielitz, and Jagerndorf. SILESIA, PnwUn. the S. E. province of Prus- sia, bounded N. by Brandenburg and Posen, E. -sian Poland and Austrian Galicia, S. by Austrian Silesia and Moravia, and S. W. and W. by Bohemia, the kingdom of Saxony, and the Prussian province of Saxony ; area, 15,556 sq. m. ; pop. in 1871, 3,707,167, of whom 1,760,- longed to the Evangelical church, 1,896,- 186 were Uoinan Catholics, and 46,629 Jews. It is divided into the districts of Breslau, Lieg- id oppeln. It is separated from the Austrian dominions by the Sudetic chain of mountain-*. which consist of long well wooded ridges with isolated peaks. There are two principal groups, the Riesengebirge in the N. W. part of the range and the Glatz mountains in the opposite direction; the most eU-vated peak of the former, the Schneekoppe, is up- ward of 5,000 ft. high, and of the latter, the iberg, n.-arly 5,000 ft. There are valleys of considerable extent. The Oder flows through the province in a general N. W. .lir.-.-ti.m. and divides it into two nearly 1 : it on tin- left of the river being mountainous, and that on the right flat. SILICON This level portion is sandy, with extensive tracts of heath and stagnant pools. A small portion of the S. E. corner is drained by the upper course of the Vistula. The mineral wealth of Silesia is confined principally to the upper or S. E. part of the province. .Gold and silver are procured in small quantities; copper, lead, and zinc are found; and coal and iron are abundant. Quarries of limestone, mar- ble and sandstone are worked. Large num- bers of cattle and sheep are raised, the wool of Silesia being of superior quality, and form- ing next to linen the chief export. The prin- cipal manufactures are of linen, cotton, and woollens, iron, paper, leather, glass, porcelain, castings, and sheet iron. Among the principal towns, besides Breslau, the capital, are Glogau, Liegnitz, Oppeln, and the fortresses Schweid- nitz, Neisse, Glatz, and Kosel. Silesia became subject to Poland in the 10th century, and in 1163 it was ruled by three independent Polish princes. It was afterward subdivided into numerous petty states, which in detail became tributary to the king of Bohemia, and fell to Austria in 1526. The claims of Frederick the Great upon the former duchies of Liegnitz, Brieg, Wohlau, and Jagerndorf, founded on an old treaty of inheritance, gave rise to three wars for the possession of Silesia, the first in the years 1740-'42, the second in l744-'5, and the last in !756-'63 (the seven years* war). By the treaty of Hubertsburg in 1763 the province was finally secured to Prussia, except the part now known as Austrian Silesia. A part of Lusatia was added to it by the treaties of 1815. SILICA. See SILICON. SILICATES, Soluble. See GLASS, SOLUBLE. SILICON, or SUieium, the essential constituent of silex or flint. It is obtained in a dull brown amorphous powder by passing the vapor of chloride of silicon over heated potassium or sodium contained in a glass tube. It may also be obtained from the aqueous solution of the gaseous fluoride of silicon. Neutralized with solution of potash, this affords a silico-fluoride of potassium, which when well dried is mixed in a glass or iron tube with T % or T 9 7 of its weight of potassium or sodium and heated. The silicon set free partially combines with the excess of the alkali, from which it is finally removed by washing in water. When heated in air or oxygen, it burns vividly, and with such intense heat as to fuse the external crust of silica. In its chemical properties silicon exhibits striking analogies with carbon and boron. When strongly heated in a close plati- num crucible, it becomes darker and of great- er specific gravity ; it loses its affinity for oxy- gen, so that it will not ignite even if heat- ed by the blowpipe and immersed in oxygen, and is not attacked by pure hydrofluoric acid. If aluminum be substituted for the sodium of the above experiment, silicon is obtained in a crystalline condition. Two methods are employed to prepare crystalline silicon : 1,
