294 MINES 



tity of pyrites, which decomposing by the action of the air, with or without .artificial 

 heat, produces sulphate of iron, and sulphate of alumina, -whence copperas and alum 

 are manufactured in great abundance. 



The calcareous formation -which surmounts the coal-measures, called by geologists 

 Zechstein, magnesian limestone, and older Alpine limestone, contains different deposits 

 of metallic ores ; the most celebrated being the cupreous schist of Mansfeld, a stratum 

 of slightly calcareous slate, from a few inches to 2 feet thick, containing copper pyrites 

 in sufficient quantity to afford 2 per cent, of the weight of the ore of an argentiferous 

 copper. This thin layer displays itself in the north of Germany over a length of eighty 

 leagues, from the shores of the Elbe to the banks of the Ehine. Notwithstanding its 

 thinness and relative poverty, skilful miners have contrived to establish, on different 

 points of this slate, a number of important explorations, the most considerable being 

 in the territory of Mansfeld, particularly near Eothenburg. They produce annually 

 2,000 tons of copper, and 20,000 marcs of silver. We may also mention those of 

 Hessia, situated near Frankenberg, Bieber, and Riegelsdorf. In the latter, the 

 cupreous schist and its accompanying strata are traversed by veins of cobalt, mined 

 by the same system of underground workings as the schist. These operations are 

 considerable; they extend, in the direction of the strata, through a length of 8,700 

 yards, and penetrate downwards to a very great depth. Three galleries of efflux are 

 to be observed ; two of which pour their waters into the Fulde, and the third into the 

 Verra. These mines have been in activity since the year 1530. Analogous mines 

 exist near Saalfeld in Thuringia. 



A very remarkable deposit of the same period, whence geologists have given this 

 formation the name of Permian, occurs in the Russian government of Perm, the sand- 

 stones containing disseminated particles of copper ore, chiefly in the form of carbonate, 

 to the distance of 400 or 500 wersts from the chain of the Oural. Some of the thick 

 flaggy grey grits contain as much as 2^ per cent, of copper, and the imperial zavods 

 near Perm are stated to yield 260 tons annually from this source. 



To the same geological formation must probably be referred the limestone which 

 contains the sparry iron mine of Schmalkalden at the western foot of Thuringerwald, 

 where there has been explored from time immemorial a considerable mass of this ore, 

 known by the name of S(akiberg. The working has been execiited in the most 

 irregular manner, and has opened up enormous excavations ; whence disastrous ' runs ' 

 have taken place in the mines. 



At Tarnowitz, 14 leagues S.E. of Oppeln in Siberia, the zechstein contains, in some 

 of its strata, considerable quantities of galena and calamine ; into which mines have 

 been opened, that yield annuallyfrom 600 to 700 tons of lead, 1,000 to 1,100 marcs of 

 silver, and much calamine. Mines of argentiferous lead are noticed at Olkutch and 

 Jawornoin Gallicia, about 6 leagues N.E. of Cracow, and 15 leagues E.N.E. of Tarno- 

 witz. From their position these have been referred to the same period. The im- 

 portant lead mines of Villach and Bleiberg in Carinthia have been shown by the 

 Austrian geologists to belong to a rather more recent formation, whilst several minor 

 lead-bearing localities of the same province occur in the Hallstadt limestone (Upper 

 Trias), and Gailthal limestone (carboniferous). 



There has been discovered near Confolens in the department of la Charentc, in a 

 secondary limestone, calcareous beds, and particularly subordinate beds of quartz, 

 which contain considerable quantities of galena. At Figeac also, in the department 

 of le Lot, deposits of galena, blende, and calamine occur in a secondary limestone. At 

 la Voulte, on the banks of the Rhone, there is mined, in the lower courses of the lime- 

 stones that constitute a great portion of the department of the Ardeche, a powerful 

 bed of iron ore. 



It used to be supposed that it is in the zechstein, or in the sandstones and trap rocks 

 of nearly the same age, that the four great deposits of the sulphuret of mercury, of 

 Idria, the Palatinate, Almaden, and Huancavdica are mined, but more recent obser- 

 vations would place some of them, at least, in rocks contemporaneous with the coal- 

 measures. See MERCURY. 



The formation which separates the Zeckstein from the lias (calcaire a grypJiites), called 

 New Red Sandstone and Red Marl in England, and Bunter-sandstein, Muschelkalk, and 

 Keuper in Germany, presents hardly any important mines except those of rock-.alt ; 

 which enrich it in Cheshire, and in many parts of continental Europe. The mines 

 of Salzburg belong to a formation somewhat higher, and those of Wieliczka, Bochnia 

 and of Transylvania, as well as of Cardona in Spain, are of Tertiary date. The 

 copper-bearing sandstones of Alderlcy Edge, in Cheshire, are of Triassic ago, and at 

 Mechernich, in Rhenish Prussia, galena is worked in a conglomerate belonging to tho 

 Bunter series. 



The lias often contains very pyritous lignites and shales, which are mined in many 



