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*' In the limits of thofc two parts we have the moft convincing 

 " proofs that it had been flint in a fimple fluid fl:ate, which had 

 " penetrated the wood, and not in a fl:ate of fokition." Why ? 

 •' becaufe the flinty fubfl;ance has proceeded to a certain length, 

 " and no further ; and there is no partial impregnation 

 " nor gradation of the flintifying operation, as muft have 

 " been the cafe if filiceous matter had been depofited from 

 " a folution *." I own I am at a lofs to perceive the force of 

 this argument, and can fee nothing in it but mere aflTertion. 



2dly, " Sulphur is found naturally combined with almofl; 

 " all metallic fubfl:ances, which are then faid to be mineralized. 

 " Now no perfon, fkilled in chymifl:ry, will pretend to faj 

 " that may be done by aqiieous folution. The combination 

 ** of iron and fulphur, for infliance, may eafily be performed 

 " by fufion ; but, by aqueous folution, this combination is again 

 " refolved, and forms a vitriol." That metals may combine' 

 •with fulphur in the moift way is a fa<5l which perhaps was 

 but little known when our author wrote ; it is however at prefent 

 fufiiciently eftabliflied. Water inay be fl;rongly impregnated 

 with hepatic air ; the fulphur is precipitated by almofh all metals 

 from this water, and in the fubterraneous meanders where they 

 meet, being proteded from accefs to atmofpheric air, there is 

 little danger of the converfion of the fulphurated metals into 

 vitriols. That fulphurated ores may be formed, without the 

 help of heat, is Incontrovcrtibly proved by their having been 



K 2 found 



* Page 233. 234- 



