MINERALOGY. 7 



demonflrate made upon the turf-moors which 

 are at the foot of the hills or high rocks in the pro- 

 vinces of Dalarne, Jemtland, and Herjeadalen, 

 in Sweden ? or, that certain vapours have pre- 

 dominated, and flill mew their power within cer- 

 tain diftri&s, where they attack, and fix them- 

 fclv.es to fuch matters as are molt agreeable to 

 them ; fo that trees, which have been buried in 

 the earth, in fome of its fubverfions, have met 

 with martial vapours in fome parts of Bohemia ♦, 

 the flint-producing principle of Loughneagh in 

 Ireland, and at Adrianople •, with the inflamma- 

 ble fubilance in the ftrata of the coal-pits in Eng- 

 land, and at Boferup in the province of Skone in 

 Sweden ? or, that fhells muft, without the deftruc- 

 tion of their calcareous principles, be changed in- 

 to a calcareous fpar, as at the Balfberg in Skone ; 

 be rilled with flint, as at Vernon in France, and 

 in Siberia •> or be penetrated with marcafite, as at 

 Andrarum in Skone ; or with a green copper 

 ore, as at Jarlfberg in Norway ? Silver feems to 

 predominate at Kongfbergin Norway, as the cop- 

 per does in the north part of that kingdom : and 

 the fame kind of ftone in which gold abounds 

 at one place of the world, may contain none at 

 all at another place -, and other fuch examples oc- 

 cur. 



I now leave this important fubjecl:, that I may 

 not difcover my farther want of knowledge there- 

 in •, but I take the liberty, at the fame time, to 

 give this advice to beginners, viz. not to con- 

 clude, that one mineral body is produced by ano- 

 ther, only becaufe they are fituated near one ano- 

 ther, if it cannot at the fame time be derrionftrat* 

 ed by the analyfis, or by artificial mutation : nor 

 to content himfelf with making his obfervations 

 on'/ on collections of minerals, or on heaps of 



B 4 ores, 



