6 A SYSTEM OF 



if I may be allowed that expreflion ; and this is 

 again to be confidered as a different method. 



Another way, and which in our times is much 

 favoured, is that of deftruction *, partly by very 

 violent means, fuch as fubterranean fires, and 

 partly by more mild ones, fuch as the weather- 

 ing, wailing, or decompounding away -, and by 

 this way we have innumerable varieties, and 

 new compofitions. The vitriolic and muriatic 

 acids, do not lie dormant 5 and being once let 

 loofe by the faid way of weathering or deftruc- 

 tion, they do not ftop till they are fatu rated with 

 fomething. Where thefe acids cannot penetrate 

 by themfelves, they are forwarded by the water, 

 which, according to the laws of nature, is almoft 

 in a conftant motion : but the effects of thefe falts 

 ought again carefully to be diftinguiflied from 

 thofe of the water alone, becaufe this latter acts 

 both as a menftruum, for inftance, upon the cal- 

 careous earth , and at the fame time by its vis in- 

 erti<e^ heavinefs and motion, wears off or abrades 

 fome particles from folid bodies, carries them 

 along, and depofits them in other places, where 

 thefe particles often acquire a different pofition 

 from what they had before. Are the Bog-ores 

 produced of decayed mundics, although no vi- 

 triolic matter is found in the waters or tracts 

 around them ? or, Are they to be reckoned a fe- 

 diment of martial earth diffolved in water alone ? 

 Would it be amifs to fuppofe, that a vegetable 

 pnould may of itfelf be changed into iron, fince 

 it is found to yield from a grain to about half of 

 Jts weight of the faid metal, as the experiments 



* The original has, " Of deftruftion that ads privative," 

 v/hich I have omitted, as it is quite unintelligible to me. 

 I}. C, 



demon- 



