ohftrved to fall from the Chuds. 149 



tain from any of thefe, would reouire an impetus of between 

 3 and 400 miles; and, if allowance be made for the refift- 

 ance of the air, ] 200 under the greatell range of 2400 miles ; 

 a force not known to exilt on the earth. It is true, volcanic 

 allies, when collected in the upper regions, will be carried by 

 the clouds to an amazing diftance. But thefe are fmall light 

 a(hes, not flones. It is evident, therefore, if thefe fubftanccs 

 originate from volcanic alhes, they mull, be formed in the 

 clouds, where thofc alhes, meeting'with carbonic, lulphuric, 

 and other acids, and mixing wilh earthy particle? drawn from 

 terreftrial objedlis, are, by the elcdric fluid in the ligbuiing, 

 precipitated from the aqueous vapours which bore them up, 

 and, becoming united, fall to the earth in the form of Itones ; 

 as in fome meafure is evinced from the flalhes ot light and 

 detonation which accompany their fall. 



Subdanccs alfo of the fame nature may be formed in the 

 clouds without tiie affiftance of volcanic matter ; for the car- 

 bonic, fulphuric, and aqueous vapours, whicli rife from mines, 

 ■furaace?, bogs, vegetables, and animals, and the fmall par- 

 ticles of filiceous and calcareous earths which colled in the 

 clouds, are decompofcd or made to alTume new arrangements 

 by the eIe«Mric fire, wliercby the minerals are generated and 

 united to the earths, and coufcquenlly fail in the foi^ih of 

 ftones. Thus ftones, by means of eledncity, are formed in the 

 clouds from the ferriferous principles al'cemiingfiom volcanos, 

 iiiines, and furnaces. Britain, indeed, is too far from any 

 volcano to fuppofe that any quantity of vokanit matter cau 

 be wafted by the winds to this ifiand; yet it contains a num- 

 ber of ferruginous mines and furnaces employed in Uie ma- 

 nufactory of that metal ; from which proceeds an immenfe 

 (juanlity of gas, containing the ferriferous n)attcr, and fuch 

 matter as is generally connected with it. Keiides, there is 

 a circumftance not generally attended to by mineralogifls — 

 that all mines of whatever nature contain a mineralogical at- 

 mofphere replete with the generic principles of the metal con- 

 tained in the rcfpective mince. That Nature, by her llow but 

 rcsiular operations, is daily producing metals from their ele- 

 ments, will hardly be denied; andwbetlur the atmofphcre of 

 which I fpeak be produced by exhalations froni the ingre- 

 dients flic employs, or a part of. the ingredients themfelvcs, 

 the cafe will be' the fame as to the Dbjctt 1 have in view. 

 'Iliis atmofphcre lias a lirong and vifible clVcCt on the flones 

 and vegetables which cover the foil, efpe( idly lh;;t which 

 covers mints of iron, lead, and copper. Animal and vege- 

 table exuvia-, and other dccaved mundics, arifmg from' bogs, 

 niorafll-s, aiid dirt-liills, produce a great quanliiy of carbonic 

 K 3 a»J 



