720 



I D R I A. 



Una 



Climate. 



Mineralogy. 



Quicksilver 

 mines. 



the Isonzo, 19 leagues lower down. This river abounds 

 with fish, among which are fine trout of remarkable 

 size. Several sluices and canals are formed in the val- 

 ley where it runs, one of which, of superior construc- 

 tion, was executed by the French in 1813, on the tor- 

 rent Woitschaik, for the purpose of floating wood. 

 Thunder storms prevail in summer, and there are 

 sometimes two or three in a day : the heat is then op- 

 pressive, owing to the reflexion of the sun from the 

 surrounding hills: autumn is rainy, and winter is of 

 long duration. The thermometer in the most severe 

 cold falls a few degrees below zero. Two chains of 

 mountains 17~>S feet high, bounding the valley of the 

 Idria, are covered with snow nearly six months of the 

 year : and 300 or iOO men are employed while storms 

 prevail, clearing the great road to Laybach. The me- 

 dium height of the barometer is &7 inches 5 lines ; 

 its variations are neither frequent nor considerable. 

 A strong prejudice subsists in the country regarding 

 the insalubrity of the climate, which of late has been 

 controverted. But although two thirds of the district 

 are forests, vegetable life is languid in the immediate 

 vicinity of the town of Idria; fruits and grain seldom 

 ripen, and cattle always decline. Tooth-ach is univer- 

 sal among the inhabitants, few persons have good teeth, 

 and they are lost by all at an early age. As the inha- 

 bitants are principally divided into miners and forresters, 

 the one class enjoys vigorous health, while the other is 

 subjected to disease : and the consequences are beheld 

 even in their respective offspring. Life is here of short 

 duration ; many die young, and forty is an age be- 

 yond which great expectations of survivance are not 

 entertained. The unusual insalubrity of Idria is traced 

 to the mines and metallurgic operations, by those who 

 consider the atmosphere of the same constitution as in 

 other places. 



The minerals of Idria are in considerable number 

 and variety, and also of uncommon value compared 

 with their narrow bounds. Among these are white 

 marble, found in the valley cf the Canomla; thick beds 

 of different coloured jasper in the country of Woiska ; 

 fine and coarse free stone ; sulphuretted iron and indi- 

 cations of coal. But the chief riches of Idria are its 

 quicksilver mines, the largest, most magnificent, and 

 most productive in the world. The metallic stratum 

 is situated about 240 yards deep ; it extends 800 yards 

 in one direction by 1000 in another: and lies in a val- 

 ley, whose surface is 507 feet above the level of the 

 sea. Six shafts penetrate the mine, four of which are 

 vertical, and two have an inclination. The former 

 are named St Barba, St Theresa, St Francis, and the 

 Emperor Joseph ; three of them are appropriated for 

 the extraction of the mineral substances, or discharging 

 water, which is accomplished by 15 pumps, worked by 

 a hydraulic wheel So feet in diameter ; while the 

 fourth is reserved for introducing the materials neces- 

 sary for the operations below. Access is gained from 

 within a spacious building, situated in the town of 

 Idria, leading almost horizontally under a lofty vault 

 to a staircase, always kept in excellent repair, con- 

 structed mostly of stone steps, but partly of wood. It 

 reaches to the depth of 150 yards, after which the re- 

 mainder of the descent is accomplished by wooden lad- 

 ders, which are sometimes damp, and on that account 

 less convenient and agreeable. Dr Brown observes, 

 that in leaving the mine, he ascended by a ladder of 

 639 staves. There are several landing places paved 

 with flag stones in the course of the descent, and 

 benches to rest upon : and the whole mine is kept re 



markably clean and in good order. The subterraneous Idria. 

 excavations are occupied by nine horizontal galleries, ^7~ 7~^ 

 including intermediate ones, with their numerous ra- Q uicksilvc r 

 mification?, about seven feet high, and as much in m 

 width. They are arched over by artificial building, un- 

 less when; they penetrate the solid rock, which requires 

 no support, and are in general well aired from currents 

 being established between them. According to Jars, 

 by whom the mine was visited about the year 1759, 

 the entrance to the principal gallery is covered by an 

 iron grating, at the moment the \\orkmen descend, 

 which is kept down until their return. At the dis- 

 tance of 260 yards from the mouth of the same gallery, 

 there is a chapel where mass is performed on all festi- 

 val days, and the images of saints, protected by a 

 grating, stand in niches. Kuttner says the principal 

 shaft is 86 fathoms in depth, and Keysler, that the 

 lowest part of the mine lies 840 below the surface of the 

 earth. The temperature of some parts is such as to 

 cause profuse perspiration in the workmen : numerous 

 thermometrical observations prove, that among great 

 beds of rich ores, the heat is from 80 to 95. Every 

 thing within seems to announce disorder and chaotic 

 confusion : the whole mineral kingdom apparently has 

 been confounded by some catastrophe, to constitute the 

 treasures which this spacious cavern contains. Enor- 

 mous heaps of shells are intermixed with mercury, 

 bitumen, and sulphur, and the ores are disseminated 

 in the most unequal manner. On account of its uncom- 

 mon arrangement, the mine of Idria bears no resem- 

 blance to any other, and presents none of those faci- 

 lities in the working which are found in mines with 

 veins. 



Considerable misapprehension seems to have prevail- 

 ed concerning the quality of the ores of Idria. Some 

 authors have affirmed, that it contains 50 per cent, of 

 metal at an average, and that portions afford even 80 

 per cent. But the mean produce of 9908 tons was on- 

 ly 8.616 per cent, by exact observation. Virgin mercu- 

 ry, as we have seen in the preceding list of combina- 

 tions, exists in various situations, elaborated exclusive- 

 ly by the hand of nature. It appears in pure globules, 

 and has been known to issue in a slender stream from 

 some narrow fissure in the rocks. A miner is said to 

 have collected 36 pounds of mercury in this manner in 

 six hours. The quantity of virgin mercury procured 

 annually is very unequal. When Dr Pope visited the 

 mines in 1663, it amounted to 11,862 pounds, which 

 nearly doubled the product of 1661, and somewhat ex- 

 ceeds the statement of Keysler and Jars, at 100 quin- 

 tals, or 10,000 lib. Probably it is more rare at pre- 

 sent. A small portion is always presented in a leath- 

 ern purse to foreigners of distinction who inspect the 

 mines. 



The ores being separated, according to their quality, Extmtio 

 by the miners, are drawn up in strong square boxes, of the 

 each capable of containing 700 or 800 lib. by means of m(;ta1 ' 

 a hydraulic wheel put in motion by the water of a ca- 

 nal led from the Idrixa. All are then conveyed to the 

 lavatories, or washing rooms, where they undergo a 

 new assorting, and the richer kinds are set apart by 

 themselves. The object of washing is to disengage all 

 the earth which contains no mercury ; and for this pur- 

 pose seven wire sieves are first employed, and the re- 

 sult then transferred to another set of very expert work- 

 men. Sieves suspended in a cistern, and, while im- 

 mersed, kept in constant^ motion, are now used, that 

 the heaviest particles may fall to the bottom ; and great 

 care is taken to preserve those of a red colour, as they 



