258 Of the Principles 



matrices, the affair principally depends on the in- 

 weathering or inhalation, for the production of 

 an ore, particularly pyrites : which inhalation on- 

 ly confiits in damps, fumes, vapours, &c. feeing, 

 from the confideration of drufe covered over with 

 ore and finter> neither induration, precipitation, 

 cryftallifation, nor vegetation, can have any 

 place. 



Thefe damps are mineral, yet not of an ore 

 and metal mixtion, but, proximately, fitted for 

 fuch a mixtion. They muft be of different forms 

 and mixtures, confequently of different powers 

 and virtues ; as the bufmefs of mineralifation 

 cannot depend on bare coction, or the nature of 

 the matrix or bed \ namely, fubtile earths, which, 

 in certain places, proportions, times, degrees of 

 warmth and cocYion, become in one place lead, in 

 another tin, &c. and when once prepared, remain 

 unchangeably the fame, tho' indeed fubject to wea- 

 thering or deftruction. 



In general, mineral damps have the following 

 origin and nature $ they proceed from all manner 

 of bodies, either animate or inanimate, though 

 from the former in greater plenty •, not only from 

 porous and loofe bodies, but alfo from the clofeft 

 and heavieft bodies, even from firm ftone, of which 

 we have an inftance in the magnet. Some bodies or 

 matters evaporate, barely by a diminution and difli- 

 pation of their entire fubftance, as pure water, vo- 

 latile falts, brandy, camphire, phofphorus, &V. 

 Other bodies evaporate by an abftra&ion and fepa- 

 ration of their highly fubtile particles from the more 

 clofe, coarfe, and earthy parts ; for inftance, a fa- 

 Jine or earthy water, either fpontaneoufly or 

 artificially. Others again exhale, by a deftruc- 

 tion both of their texture and mixture 5 as ap- 

 pears 



