237 



and fitted, for being deposited in strata of coal ; and that the coals, 

 with their concomitant strata, were among the last that were formed. 

 But how, and by what means, every thing in this great work was 

 fitted, and carried on, belongs to higher wisdom and intelligence 

 than mine to explain*/' 



" I will beg leave," Mr. Williams saysf , " to propose another pro- 

 bable source of coal. I believe, I may call it a real one, and that 

 is the antediluvian peat-bog/' The grounds on which Mr. Williams 

 formed this opinion were, the having seen coals, which seemed to 

 bear a very strong resemblance to peat ; and, on the other hand, 

 peat, which, on being dried, became nearly as black, and as hard 

 as coal. The particular reasons Mr. Williams employs for this latter 

 opinion, I shall at present defer, since they will appear when I shall 

 presume to offer some conjectures on this subject. Petroleum, Mr. 

 Williams is, however, convinced, is not at all concerned in the for- 

 mation of coal; although he acknowledges that some species of 

 petroleum may have a near relation to coal. 



It is right to apprise you, that not only has tfre conversion of 

 petroleum into coal been thus strenuously opposed, but that the 

 derivation of petroleum itself from vegetable matter is also denied. 

 The learned Wallerius strongly objects against such an origin; 

 grounding his objections chiefly on it differing so much in its sen- 

 sible, as well as chemical qualities, from vegetable matter. He is 

 the more confirmed in his opinion, from the petroleum being found 

 inclosed in mountains, and in subterranean cavities, where no traces 

 of decayed vegetables are to be seen. Considering also, that 

 there is no reason to suppose that nature is less disposed to form 

 an oil in the mineral kingdom, than in any of the others, he con- 

 cludes that naphtha is generated from a most subtile inflammable 



* History of the Mineral Kingdom, vol. ii. p; 212. f Id. vol. ii. p. 1 94-. 



