SILVER. 



quartz imbedded in it, indicates rich ore ; but a coarfe clay, 



deftitute of quartz, efpecially when it increafes in quantity, 

 and occupies the whole vein, renders it unproduftive, or 

 entirely barren. The ores of the vein now deicribed are 

 rich filver and copper pyritc?, with fluor fpar, blende, various 

 copper-ores, and lomctimes native filver and copper. 



Joachimjlhal, a place in the fame circle, has been long 

 celebrated on account of its valuable mine?. The prevailing 

 rocks are defcribed as grey micaceous and quartzofe clay- 

 flate, which at a great depth became more of an argillaceous 

 nature, foft, foliated, and of a blaclt colour. The mountains 

 around this place have a gentle decHvity towards the fouth, 

 but run in lofty ridges to the call, north, and well, and are 

 interfered by deep vallies. This inequahty of lurface af- 

 fords great accommodation to the miners to open numerous 

 galleries, which converge to the fouth, and to the valley in 

 which (lands the town of .loachimlthal. All the galleries 

 and works of this dillrift are divided into fix different fields, 

 belonging to tl e iame number of companies, and they are 

 drained by two deep drifts or levels ; the one of which riins 

 in a direct line 1600 fathoms; but including its feveral 

 branches, its whole length is 4500 fathoms. The depth un- 

 der the highelt tops of the mountain is 170 fathoms : the fe- 

 cond great level, which runs through the fpace of 5600 

 fathoms, and in a direct line 1500 fathoms, is 20 fathoms 

 deeper than the firft ; but the operations in the mines have 

 been carried to a much greater depth ; for at the time in 

 which they were vitited by Ferber, before 1774, the perpen- 

 dicular depth under the furface was from zoo to 3J0 faihoms, 

 and, excepting the mines in the Tyrol, were then confidered 

 as the deeped in the world. 



The thicknefs of the veins varies from one inch to two 

 feet ; and the vein-iloncs are a whitifh or blueilh clay, ar- 

 gillaceous flatc, and reddilh horn-itone, or petro-filex, which 

 is the matrix of the ricliell ores. The filver-ores which are 

 found in this mining diltrift are, native filver, which is at- 

 tached to different vein-ftones, and affumes various forms ; 

 vitreous filver-ore, which is dug out fometimes in very large 

 malies, and is confidered as a very rich ore ; one hundred 

 weight being commonly valued at 180 marks of filver : red 

 filver-ore, fumetimcs beautifully cryitalli/cd and tranfparent, 

 is attached to red horn-ltone or calcareous fpar ; and white 

 tilver-ore has fcmetimes but rarely appeared. 



The filver-mines of Berejliult, in the circle of Tabor, are 

 in hills of a gentle, declivity, and compofed of grey or blueiih 

 clay-flate, in which appear figures of greenilh lithomarge, 

 or femi-indurated pot-(tonc. Thefe mines were forn>erly rich 

 in native filver, and other ores of that metal. A vein to the 

 welt of this place, which traverfed a hard rock, contained 

 reddifli-coloured felfpar, with galena, blende, and a little 

 (ilver ; but from the part where a vein containing white ar- 

 fenical pyrites came into the hanging fide, the vein produced 

 native filver, vitreous, red, and white filver-ore. Another 

 vein in the fame place, which is from two inches to one foot 

 in width, is obferved to be rieheft where it is thinneft. It is 

 chiefly enriched by an undulating black clay fidure, which 

 appears fometimes in the iianging fide, and then it produces 

 red and white filver-ore. When crolled by veins running 

 from e.ilt to weft, it appears to be cut off and barren, till 

 beyond the place of Junftioii it again becomes produiftive 

 in Its former courfe. 



Sweden. — The filver-iniiies of Salberg, in Wellmania, are 

 about 28 Englifh miles from Upfai. Tlic ore i~ an argen- 

 tiferous galena, yielding from one marc to a marc and a half 

 of filver per quintal ; it is in compaft lime-ftone, and has been 

 worked to the depth of i jo fathoms. The average profits 



amount to about 4C00/. and one-eighth is paid to the June 

 Porter's Travels. 01- g. 



Norivay.—Thc filver-minesof Konigfberg, in Norway, are 

 fituated in mountains of moderate height, compofed of 

 nearly vertical beds of mica-flate with garnets, and of grey 

 quartz mixed with fine black mica, and a little lime-ftone 

 and red horn-ftone. Other beds are compofed of a ferru- 

 ginous rock, which, in the upper part of the mine, is 33 

 feet thick, but in the lower not more than 6 feet thick. 



The veins are from half an inch to two feet or more iij 

 thicknefs, and cut the ftrata tranfverfely. The matrix of 

 the ore is granular lime-ftone, fometimes intermixed with 

 fluor fpar. Enormous maffes of native filver have fometimes 

 been found in this mine ; one is mentioned as weighing 2 2olbs. 

 The common ores arc native filver and vitreous filver. The 

 veins arc molt produftive in the ferruginous rock. The an- 

 nual produce is about jooolbs. weight of filver. 



/Ifta. — The filver-mints of Zmeof are fituated in thai 

 part of the Altaian chain of mountains which lies between 

 the Oby and Irtifch, from 50^ to 52- north latitude. The 

 annual produce has been ftated at 60,000 marcs of filver, 

 which is alloyed witii about 3 per cent, of gold. The mines 

 of Nertfchink in Daouria, near the river Amur, yield ar- 

 gentiferous galena, producing about 30,000 marcs of filver, 

 and containing l\per cent, of gold. The Ruflian merchants 

 who trade to China bring back ingots of filver, from feve- 

 ral ounces to a pound weight, in exchange for their commo- 

 dities ; hence it may be inferred, fays Patrin, that there are 

 filver-mines on the frontiers of China. Patrin, Hift. des 

 Mines. 



America. — The molt produdtive filver-mines in the world 

 are thofe of South America and New Spain. Thofc of 

 Peru, for many years after its conqueft by the Spaniards, 

 yielded the greateft quantity of filver ; but at prefent the 

 mines of Mexico are the rieheft. The mines of America 

 furnifli both filver and gold ; and in making an eftimate of 

 their lichnefs, we mull take an account of each of thefe 

 metals. The following table, given by M. Humboldt, will 

 ftiew the diftribution of thefe mineral trcafures in the dif- 

 ferent parts of the new world ; the kilogramme being 

 2 lbs. 3 oz. 5 dr. avoirdupois, or rather more than 2 lbs. 

 8 oz. troy. 



C<p|(l. Silver. 



Viceroyalty of Peru - - 782 140,478 



V'iceroyalty of New Spain - 1,609 S37iS'2 



Capitania of Chili - - 2,807 6,827 



Viceroyalty of Buenos Ayres - 506 1 10,764 



Viceroyalty of Grenada - - 4>7'4 



Viceroyalty of Bralil - - 6,873 



Kilogrammes 17,291 



995,581 



The above was the annual produce of the different dif- 

 trids, at the beginning of the 19th century ; from which it 

 appears, that the total weight of the precious melal^^ from 

 all the mines in America, reduced to Englifii pounds troy, 

 is 45,580 lbs. of gold, and the enormous quantity of 

 145,000 lbs. of filver ; equal in weight to one-third of the (in 

 produced by the mines in Europe. Dr. Adam Smith, in his 

 " Wealth of Nations," values the gold and filver aiunially 

 exported into C':idiz and Lilbon at o[ily fix million* licrling, 

 including not only the regiftered gold and filver, but that 

 winch may be fnppoled to lie fmuggled. This eftimate i(> 

 only two-fitths of the real annual amount. 



The- mountain of Potofi has (urniftied, fince its difcovcry 

 in 1545, a maf'j of filver equal in value to 234,093,840/. 



llerling. 



