MERCURY 229 



Tho great mines of Idria in Friuli, in the county of Goritz, were discovered in 

 1497, and the principal ore mined there is the bituminous cinnabar. The workings 

 of this mine have been pushed beyond the depth of 280 yards. The product in quick- 

 silver might easily amount annually to 6,000 metrical quintals =600 tons British; but, 

 in order to uphold the price of the metal, the Austrian Government has restricted the 

 production to 150 tons. The memorable fire of 1803 was most disastrous to these 

 mines. It was extinguished only by drowning all the underground workings. Tho 

 sublimed mercury in this catastrophe occasioned diseases and nervous tremblings to 

 more than 900 persons in the neighbourhood. 



The mines of Almaden according to Pliny supplied the Greeks with red cinnabar 700 

 years before the Christian era ; and Eome, in his time, annually received 700,000 

 pounds from the same mines. Since 1827, the Almaden mines have produced 22,000 

 cwts. of mercury every year, with a corps of 700 miners and 200 smelters ; and, 

 indeed, the veins are so extremely rich, that though they have been worked pretty 

 constantly during so many centuries, the mines have hardly reached the depth of 

 330 yards, or something less than 1,000 feet. The lode actually under exploration 

 is from 14 to 16 yards thick, and it becomes thicker still at the crossing of the veins. 

 The ores yield in their smelting works only 10 per cent, upon an average; but there 

 is no doubt, that nearly one-half of the quicksilver is lost, and dispersed in the air, to 

 the great injury of the workmen's health, in consequence of the barbarous apparatus 

 of aludels employed in its sublimation ; an apparatus which has remained without 

 any material change for the better since the days of the Moorish dominion in Spain. 

 M. Le Play, who published, in the Annales dcs Mines, his Itinerairc to Almaden, says, 

 that the mercurial contents of the ores are notablement plus elevces than the product. 



These veins extend all the way from the town of Chillon to Almadenejos. Upon 

 the borders of the streamlet Balde Alogues, a black slate is also mined which is abun- 

 dantly impregnated with metallic mercury. 



These celebrated mines, near to which lie those of Las Cuebas and of Almadenejos, 

 after having been the property of the religious knights of Calatrava, who had assisted 

 in expelling the Moors, were farmed off to the celebrated Fugger merchants of 

 Augsburg; and afterwards explored on account of the government, from the date 

 of 1645. Their produce was, till very lately, entirely appropriated to the treatment 

 of the gold and silver ores of the New World. 



The mines of the Palatinate, situated on the left bank of the Rhine, though they 

 do not approach in richness and importance to those of Idria and Almaden, merit, 

 however,, all the attention of the government that farms them out. They are nu- 

 merous, and varied in geological position. Those of Drey-Konigszug, at Potzborg, 

 near Kussel, deserve particular notice. The workings have reached a depth of more 

 than 220 yards ; the ore being a sandstone strongly impregnated with sulphuret 

 of mercury. The produce of these mines is estimated at about 30 tons per annum. 



There are also in Hungary, Bohemia, and several other parts of Germany, some 

 inconsiderable mines of mercury, the total produce of which is valued at about 30 or 

 40 tons on an average of several years. 



The mines of Huancavelica, in Peru, are the more interesting, as their products aro 

 directly employed in treating the ores of gold and silver which abound in that portion 

 of America. These quicksilver mines have been explored since 1570, the actual pro- 

 duce of the explorations being, according to Helms, about the beginning of this 

 century, from 170 to 180 tons per annum. 



In 1782 recourse was had by the South American miners to the mercury extracted 

 in the province of Yun-nan, in China. 



The mercurial mines of California are thus described by Dr. Tobin : 



' That part of California where I have been residing, and that which I have just 

 visited, consists of three long ranges of trap mountains, with two wide valleys dividing 

 them, the valley of the San Joaquin, and the valley of Santa Clara. Near this last 

 place are the quicksilver mines of New Almaden, where I have been working. Tho 

 matrix of the cinnabar ore is the same trap of which the mountain ranges are com 

 posed, and as yet only one great deposit of this ore has been found, though traces 

 of quicksilver ores have been discovered in other places. The ores are composed 

 solely of sulphuret of mercury (averaging 36 per cent.), red oxide of iron, and silica ; 

 and, had the mine been properly worked from the commencement, almost any quan- 

 tity of ore might be extracted ; it now, however, more resembles a gigantic rabbit- 

 warren than a mine. Its greatest depth is about 150 feet, and the weekly extraction 

 of ores varies from 100 to 150 tons. 16 cylinders are at work, producing 1,400 to 

 1,500 Ibs. daily. 



Mr. Kussell Bartlett, the United States Commissioner on the Mexican and United 

 States Boundary Question, who visited California in 1853, states that the quantity of 

 quicksilver produced annually at New Almaden, exceeds 1,000,000 Ibs. During tho. 



