I DRI A. 



721 



IJro. 



contain cinnabar. After these two levigations the ores 

 are pounded, and again carried to the lavatories to un- 

 dergo a third on inclined planes. From the lavatories 

 they are conveyed to furnaces to be subjected to distil- 

 lation ; but, before being exposed to the action of the 

 fire, the whole are rigorously assayed, in order to anti- 

 cipate what product may reasonably be expected. As 

 there are two kinds of ore, one in large pieces and the 

 other in powder, there is a furnace for each. The fur. 

 nace destined to receive the first has two fire-places and 

 four chambers or ovens, which communicate by lateral 

 conduit* with two rows of reservoirs, or very high 

 chambers of mason work, separated by intermediate 

 walls, but mutually communicating by means of alter- 

 nate apertures a foot square. Of these reservoirs or 

 condensers there are twenty-eight. The second fur- 

 nace, appropriated for burning the ores in powder, has 

 six furnaces and twenty-four chambers, instead of twen- 

 ty-eight. The area in both is inclined to facilitate the 

 flowing of the mercury, and a conduit common to the 

 whole condensers brings the mercury into another great 

 reservoir, where it is collected for use. The charge of 

 the first furnace is 30.000 lib. of ore, that of the second 

 60,000. When the furnaces are charged, all their aper- 

 tures, and those of the condensing chambers, are care- 

 fully luted with clay and slacked lime. The fire is then 

 progressively augmented during nine hours, until the 

 earthen clods, wherein pieces of ore or the powder have 

 been put, become red hot, and the ores burn vehement- 

 ly. The whole is then allowed to cool for six days, and 

 the mercury, completely disengaged, is collected in the 

 general renervoir. As the beat of the furnace, particu- 

 larly of that which burns the larger pieces, is retained a 

 long time, it would be difficult to collect the metal 

 sooner. A single charge of the furnaces will frequent- 

 ly produce 8000 pounds of quicksilver. The mercury 

 i taken out of the common reservoir, and packed in 

 white sheep-skin bags, which have been tanned with 

 alum, in quantities of 25, 50, or 100 pounds. The bags 

 are then conveyed to a magazine, where each is cover- 

 ed by a second skin, and packed up in cask*, which are 

 exported to the various place* where they are required. 

 But, independent of the pure mercury thus obtained, 

 and exported from Idria, there are mercurial prepara- 

 tions to a very great extent of all the different kinds 

 which are known in commerce. With the exception 

 of Chinese vermilion, the product* seem scarcely MIS. 

 cepcible of improvement. For these purpose* there is 

 ious building, divided into three great laborato- 

 The first i* appropriated for amalgamation of 

 or and mercury, which i* then converted to cin- 

 nabar ; the second i* consecrated to the prv|taration of 

 vermilion, wherein eight mill* are employed in grind- 

 ing the cinnabar ; and in the third there arc twenty-two, 

 furnace*, each provided with six large iron capsule*. 

 Much accessory apparatus i* used besides. 



In addition, and subsidiary to the mining establish 

 ment, and that for mercurial preparations at Idria, there 

 are several branches of art* and manufacture*. These 

 consist chiefly of a glass work, for providing the bottles 

 and window glass ; a pottery for all the earthen ware 

 required ; a tannery for preparing the leather packages ; 

 and a rope work which furnishes cordage. Numerous 

 mechanics, and artisans of all descriptions, are also 

 ready to provide the net-canary apparatus for the various 



.,J Tit. '.!.. 



A* the minen of Idria are the most productive which 



are known, it may not be uninteresting to learn thequan- 



i' metal obtained from them. It has been different 



at different period*, which i* not surprizing, considering 



VOL. xi. FART u. 



the uncertainty which attend subterraneous researches. Hn'a. 

 In the year 1663, they produced 255,981 pounds. v - Y ' 

 About the year 1730, the quantity seems to have been < * ulcksllveT 

 360,000; twenty years later it was calculated at 300,000; "' 

 and in the year 1799, Kuttner was informed that the 

 product has been known to amount to 1,000,000 or 

 1,200,000 pounds, which is probably erroneous. But 

 by an accurate computation made by the director of the 

 mines under the French regime between the years 

 1809 and 1813, we learn that the average quantity ob- 

 tained yearly in that time amounted to about 365,928 

 pounds. Of the total product, there were delivered 

 into the magazines the following proportions in quin- 

 tals of 100 pounds each. 



Mercury 14,194 quintals 25 lib. 



Cinnabar 702 25 



Vermilion ...... 2,700 29 



Corrosive sublimate . . 24 50 



Calomel 64 



Red precipitate .... 23 67 



17,713 96 



The whole of this was obtained in 56 months. Thus 

 the profits of the mines, which are the property of the 

 Emperor of Austria, and carried on at his expense, are 

 very considerable ; being at a medium about 800,000 

 francs, or 35,000 Sterling yearly. To render the 

 average nearly the same, the rich and poor ores are 

 worked at once. 



A great quantity of the quicksilver was formerly ex- 

 ported to Spain, and from thence to South America, 

 where it was employed in the separation of the metal in 

 the silver mines. The Dutch were accustomed to pur- 

 chase 100.000 lib. yearly. Most part of it is now car- 

 ried to Vienna, and a large proportion to England. 



In the year 1663, there were '^80 miners, but at pre- 

 sent 7< are employed, besides SOO wood cutters, who 

 are under an inspector general ; and there are nearly 

 600 pensioners, including women and children. The 

 whole of this great establishment is under the most 

 admirable system of administration. All the work* 

 men are divided into companies; they assemble at three 

 in the morning, when their names are called over, and 

 they descend into the mine, each with a lamp in his 

 hand. Owing to the high temperature of the galleries, 

 the rarefaction of the air, and evolution of certain gasses 

 in the combustion of the lamps, as well as the delete, 

 rious f fflu\ ia escaping from the metals, their health suf- 

 fers severely. Those who are occupied where native 

 mercury is found, inhale small particles of it, and very 

 soon lose their teeth ; those employed in sweeping the 

 chambers of condensation also inspire a considerable 

 quantity of metal while detaching it from the sides of 

 the condenser:. Thus they undergo a copious saliva- 

 tion. " We saw there," says Dr Pope, " a man who had 

 not been in the mines above half a year before, so full of 

 mercury, that putting a piece of brass in his mouth, or 

 rubbing it in his fingers, it immediately became white 

 like silver. I mean it had the same effect as if he had 

 riilihed mercury upon it. And so paralytic, that he 

 could not, with both his hands, convey a glass half full 

 of wine to his mouth, without spilling it, though he 

 loved it too well to throw it away." Some observers 

 affirm, that the quicksilver insinuates itself into the bo- 

 dies of tlio*e who work the virgin mercury, so that when 

 they go into the warm bath, or are put into a profuse 

 sweat by steam, drops of pure mercury have been known 

 to issue through the pores from all parts of their bodies. 

 This much i? certain, however, that the workmen who 

 have been occupied several years in the furnaces, become. 

 1 V 



