MINES.

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Ekrenfriedersdorf, Johaima-Georgenstadt, Annaberg, Oberwiesenthal , and Schneeberg.Those of the last three localities produce also cobalt.

The mines of Saint-Georges, near Schneeberg , opened in the fifteenth century as ironmines, became celebrated some time after as mines of silver. Toward the end of thefifteenth century, a mass of ore was found there which afforded 400 quintals of silver; on.that lump, Duke Albert kept table at the bottom of the mine. Their richness in silver■ has diminished since then; but they have increased more in importance during the lasttwo hundred years, as mines of cobalt, than they had ever been as silver mines. Saxony is the country where cobalt is mined and extracted in the most extensive manner. Itis obtained from the same veins with the silver. Smalt, or cobalt-blue, is the principalsubstance manufactured from it. The lead and the copper are in this country only ac-cessory products of the silver mines, from which 120,000 lbs. avoird. of the first of thesemetals are extracted,'which are hardly sufficient for the metallurgie operations ; andfrom 50,000 to 60,000 lbs. of copper. A little bismuth is extracted from the mines ofSchneeberg and Freyberg. Some manganese is found in the silver mines of the Erzge-birge , and particularly at Johanna-Georgenstadf.

The mines of Saxony produce a little argentiferous galena, and argentiferous graycopper; the minerals with a base of native silver are the principal ores ; they are treatedin a great measure by amalgamation. All those of Freyberg are carried to the excel-lent smelting-house of Halsbriick, situated on the Malde, near that city. The averagerichness of the silver ores throughout Saxony is only from 3 to 4 oz. per quintal: viz.,nearly equal to that of the ores of Mexico , and very superior to the actual richness ofthe ores of Potosi. The silver extracted from them contains a little gold. The Saxonmines produce annually 52,000 marcs of silver. Of these, the district of Freyberg alonefurnishes 46,000; and among the numerous mines of that district, that of Himmelsfurstof itself produces 10,000 marcs.

Silver mines exist also on the southern declivity of the Erzgebirge , which belongs toBohemia, at Joachimsthal and Bleystadt, to the northeast of Eger. Argentiferous galenais chiefly extracted from these. The mines of Joachimsthal have been explored to adepth of 650 yards. They were formerly very flourishing; but in 1805 they were threat-ened with an impending abandonment. The ancient mines of Kuttenberg , situated in•be same region, have been excavated, according to Agricola, to upward of 1,000 yardsfrom the surface soil.

The southern slope of the Erzgebirge possesses cobalt mines like the northern slope;but they are of much less importance. Some occur, particularly in the neighborhood,of Joachimsthal . Lastly, on the same slope, slightly-productive copper mines are men-tioned at Groslitz, near Joachimsthal ; at Catharineberg, 8 leagues north of Saatz; andat Kupferberg, lying between the two. At Groslitz, the ore is a cupreous pyrites, ac-companied by blende. The ores of Catharineberg are argentiferous.

Next to the silver mines, the most important explorations of the Erzgebirge are thoseof tin. This metal occurs in veins, massive, and disseminated in masses of hyalin grayquartz, imbedded in the granite; it is also found in alluvial sands. The most important tinmine of the Erzgebirge is that of Altenberg, in Saxony , which has been under workingsince the fifteenth century. Some tin is mined also near Gayer, Elirenfriedersdorf, Jo-banna-Georgenstadt, Scheibenberg, Annaberg, Seifl'en, and Marienberg, in Saxony . AtZinnwald it is also found; where the stanniferous district belongs partly, to Saxony andPartly to Bohemia ; as also important mines occur in-the latter territory at Schlacken-^ald and Abertham,and slightly-productive ones at Platten and Joachimsthal . In sev-eral of these mmes, particularly at Altenberg and Gayer, fire is employed for attackingIhe ore, because it is extremely hard. In almost the whole of them, chambers of toogreat dimensions have been excavated, whence have arisen, at different epochs, vexa-tious sinkings of the ground. One of these may still be seen at Altenberg , whihh is 130yards deep, and nearly 50 in breadth. The mines of Abertham are explored to a depth°f 550 yards, and those of Altenberg to 330. The tin mines of the Erzgebirge produceannually 484,000 lbs. avoird. of this metal.

The tin ores are accompanied by arsenical pyrites, which, in the roasting that it un-dergoes, produces a certain quantity of arsenious acid.

. The Erzgebirge presents also a great, many iron mines, particularly in Saxony , atRodenberg, near Cradorf, in the county ol Henneberg, where the workings penetrate toa depth of 220 yards, and in Bohemia , at Flatten, where may be remarked especiallyll >e great explorations opened on the vein of the Irrgang.

There is also in the Erzgebirge a mine of anthracite (stone coal) at Scluenfeld, nearbrauenstein, in Saxony .

The ancient rock-formations which appear in the remainder of Bohemia , and in theadjacent portions of Bavaria, Austria, Moravia , and Silesia, are much less rich in metalsIban the Erzgebirge . No explorations of much importance exist there.

The Fichtelgebirge , a group of mountains standing at the western extremity of the «

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