At Crenmitz, the direction of the vein in the principal mine is north and south, inclined from the west the east, according to an angle which varies from 25° to and 40°. ore consists of auriferous quartz, speck led with minute glittering particles of auriferous pyrites, and penetrated either by a buff-coloured clay, or by an ar gentifrrous sulphuret of lead, and the oxide of iron.
of working the mines is fourfold. 1 s t , By a horizontal level, following the direction of the vein. 2dly, By an inclined plane, ascending according to its inclination; forming always stages of wood, as galleries for the work men. Sdly, By an inclined plane, descending in the con trary direction. 4thly, By an excavation on either side of the vein, which is the most frequent at Schemnitz, owing to the great width of the veins." The apparent care, neat ncss, and advantage, with which the works are carried on ; the spacious entrances into their mines ; their dry, airy, and cleanly levels ; and the great encouragement given to the study of mineralogy, and to all mining speculation, chew that the Germans surpass every other nation in skill and in dustry in the art of mining.
Dr Clarke, from whose excellent work we have extract ed the preceding account of the Hungarian mines, has given us the following description of the process employed fur the reduction of their ores : " 1st, The first operation with the produce of the mine is of course that common to all mines, of stamping ore. But the richer ores are not submitted to the stamping machines.* They are carefully broken with hammers in to small pieces about the size of beans, which, being mix ed with lead, a single operation of the furnace is sufficient for their reduction. With regard to the common ores, af ter being vamped and washed, they are brought in the form 01 a fine powder or sand to Cremnitz. Here they are ex posed to what is called the crude fusion, being simply smelted into a compound regulus, which is called lech, con sisting of all the following metals, besides sulphur : gold, silver, lead, copper, iron, arsenic, bismuth, and cobalt. This is the first operation.
2d, The second operation relates to the treatment of the lech, or result of the first crude fusion. This is exposed to a furnace, the fire of which is regulated in the following manner : First, there is a layer of wood,- then a layer of charcoal, and lastly a layer of the lech, broken into pieces.
The fuel being ignited, the lech is here roasted for the eva poration of the sulphur.
3d, A third operation then follows : After the lech has been roasted, they add to it powder of the richer ores, and the whole is smelted in another furnace. This is called the second Insion, or the fusion enriched.
4th, The result or regulus obtained from the second fu sion is then carried to another furnace. Here it is again smelted, with the addition of the richest ores. This third fusion is called the fusion upon lead ; because, when the furnace is tapped, and the metal begins to flow into a re ceiver made with charcoal and clay, they cast lead upon it : this, after smelting, combines with the gold and silver. and falls to the bottom of the vessel. During this opera tion, the lighter metals, such as copper, iron, cobalt, bis muth, and arsenic, rise to the surface, and are raked off in the form of scorice, which they carry, as lech, to be fused again in the first operation. The lead, thus combined with gold and silver, is collected into large crucibles, and car ried to the fourth fusion, or, fifth operation, fur the separa tion of the lead.
5th, The furnace used for the separation of the lead is called a purification furnace. The shape of it resembles a hollow sphere, whereof the upper part is so contrived. that it may be taken off like a lid, being raised by large chains. Here the richest ores that can be procured are added to the compound of lead, silver, and gold ; and the whole is fused, not with chat coal, but by means of a flame drawn over the superficies,,uninterruptedly, for twenty-four hours at least. During this process, the lead becomes cal cined. A portion of it is absorbed by the bottom of the furnace, consisting of wood-ashes and silica ; another por tion escapes in a gaseous form ; but the greater part is raked off as it rises to the surface, in the form of galena, by men employed with instruments for that purpose. Dur ing all this operation, the gold and silver concentrate more and more, until at the last they are found pure and com bined together in a cake of metal. at the bottom of the rification furnace. Then follows the sixth and the most beautiful of all the operations,—that of separating the gold from the silver.