280 MINES 



plains of these regions, oiten salt-deserts, exhibit remarkable sandstones and pudding- 

 stones ; as also vesicular rocks of a volcanic aspect. It appears that the metalli- 

 ferous limestone is much dislocated, and the lead-veins are subject to several irregu- 

 larities, which render their exploitation difficult and uncertain. The mines lie chiefly 

 near the banks of the Schilca and the Argoun, in several cantons, at a considerable 

 distance from one another ; wherefore it was requisite to build a great number of 

 smelting-furnaces. The want of wood has placed difficulties in the working of some 

 of them. The ores are principally oxides and carbonates of lead, with brown oxide 

 of iron, calamine, and a varying proportion of native silver, occurring seldom in 

 regular bodies, but generally in cavernous openings, more or less united by narrow veins. 



The silver extracted from the mines of Daouria, contains a very small proportion of 

 gold. M. Patrin says that their annual product was, towards the year 1784, from 

 30,000 to 35,000 marcs of silver. Since that time it has diminished. The exploita- 

 tion of some of the mines of Daouria goes back to the end of the 17th century. It 

 had been commenced in some points by the Chinese, who were not entirely expelled 

 from this territory till the beginning of the following century. Many of the mines 

 are reputed to be exhausted : among the best of the now existing works are those of 

 Akatouiefsk, Algatchinsk, and Ivanofsk. 



Besides the lead mines, there are some unimportant mines of copper in Daouria, 

 and in different explorations of this region, arsenical pyrites, from which arsenious 

 acid is sublimed in factories established at Jutlack and at Tchalbutchinsky. 



About 45 leagues to the S. of Nertschinsk the mountain of Odon-Tchelon occurs, 

 celebrated for the different gems or precious stones extracted from it. It is formed of 

 a friable granite, including harder nodules or balls which inclose topazes : it is very 

 analogous to the topaz-rock of Saxony. In this granite there are veins containing 

 cavities filled with a ferruginous clay, in which are found emeralds, aqua-marines, 

 topazes, crystals of smoked quartz, &c. Multitudes of these minerals have been ex- 

 tracted by means of some very irregular workings. The mountain of Toutt-Kaltoui, 

 situated near the preceding, offers analogous deposits. The presence of wolfram had 

 excited hopes that tin might be found in these mountains ; hopes which have been 

 realised by its discovery on the Onone. There are some unworked deposits of sulphide 

 of antimony in this country. 



Considerable attention has of late years been directed to the tributaries of the Amour 

 river, many of which have yielded large quantities of gold, and some districts on tho 

 northern borders of the sea of Okotsk, are reported as being rich in ores of silver. 



MIXES OP HUNGARY. 



It must be premised of this country, that many of the metalliferous formations which 

 used some years ago to be considered of high geological antiquity, have been proved 

 to belong to the secondary, and oven to the tertiary period ; whence it is only as a 

 matter of convenience rendered the more needful by a number of undetermined 

 questions, that all the mines are here classed together. 



The metallic mines of this kingdom, including those of Transylvania, and tho Ban- 

 nat of Temeschwar, form four principal groups, which we shall denote by the group 

 cf the N.W., group of tho N.E., group of the E., and group of the S.E. 



The group of the North- West embraces the districts of Schemnitz, Kremnitz, Kojnigs- 

 berg, Neusohl, and the environs of Schmoalnitz, Bethler, Eosenau, &c. 



Kchemnits, a royal free city of mines, and the principal centre of the mines of 

 Hungary, lies 25 leagues to the N. of Buda, 560 yards above the sea, in the midst 

 of a small group of mountains covered with forests. The most part of these moun- 

 tains, the highest of which reaches an elevation of 1,130 yards above the ocean, are 

 formed, of barren trachytes (rough trap-rocks) ; but, within their ambit, a formation 

 is observed, consisting of greenstone porphyries, connected with syenites, passing into 

 granite and gneiss, and including subordinate beds of mica-slate and limestone. It is 

 in this formation that all the mines occur. 



It has been long known that the greenstone porphyries of Schemnitz have intimate 

 relations with the metalliferous porphyries of South America. M. Beudant, on com- 

 paring them with those brought by Von Humboldt from Guanaxuato, Eeal del Monte, 

 &c., lias recognised an identity in tho minutest details of colour, structure, composi- 

 tion, respective situation of tho different varieties, and even in'thc empirical character 

 of effervescence with acids. 



Tho metalliferous rocks of Schemnitz appear in a tract of a few miles in extent, 

 and are traversed by a principal group of five master-lodes coursing N.E. and S.W., 

 besides a great number of less important veins, which occur on the north side of the 

 ridge of tho Paradise mountain. The most powerful of the first of these, the Spitaler 

 Gang, attains occasionally a width of from 10 to 20 fathoms ; and is traceable for 





