n6 Of the Copper 



felf, all forts of vitriol, even that principally from 

 iron, have to this day no other appellation than that 

 of copper-water ; the iron being confidered as fome- 

 thing incidental, even by modern mineralifts. 



Copper, however, has a t very extenfive fpread in 

 the pyrites ; in regard to place, yield, and alfo 

 might inefs, as miners ufually fpeak, with refpect to 

 the breadth and thicknefs of their veins. As to 

 place, there is fcarce a mine, without fome appear- 

 ance of copper-ore. 'Tis found in all forts of earth 

 anj (tone ; in fhiver, lime-ftone, quartz, fpad, 

 kneijs ? and gemfs : though it generally appears, that 

 the pyrites in clays, lutes, and lime-ftone, are for 

 the mod part principally irony ; and often pure 

 and unmixed ; whereas copper-ores, either poor or 

 rich, muft be fought for in quartzy, fpathy, fhivery, 

 anc iv like ftone. Copper -pyrites, or ore, breaks 

 at different depths ; in fome places, in day veins, 

 as has been laid above, aimoft beneath the under- 

 lie rf-earth •, though rarely, and as may be eafily 

 imagined, thinly fown, and not fo mighty as in the 

 deeps-, in other places, and more frequently, in the 

 depth \ of which the famous mines at Fahlun in 

 Sweden are pregnant inftances. 



Here I have often put the queftion to myfelf ; 

 whether the pyrites does, with the depth, decreafe 

 in iron, and increafe in copper yield ; namely, with 

 thus view ; whether the common pyrites, employed 

 in making fulphur and vitriol, and in the operation 

 of crude-fmelting, and in metal pure iron almoft 

 decreafes with the depth ; that is, becomes weaker or 

 fmaller in veins ? or whether, like other ore veins, 

 as lead and copper, it rather encreafes? And ro 

 mention only the pyrites-copper-ore, it is well 

 known, that downwards it ftill grows mightier or 



larger * 



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