198 MR « hatchett's observations 



may thus be extracted from fome of them, is petroleum. In 

 thefe, the procefs of bituminization (if I may be allowed to 

 employ fuch a term) appears to have been completed, whilft: 

 in the Bovey coal, and efpecially in the fubftance which ac- 

 companies it, nature feems to have performed only the half 

 of her work, and, from fome unknown caufe, to have flopped 

 in the middle of her operations. But, by this circumftance, 

 much light is thrown on the hiftory of bituminous fubftances ; 

 and the opinion, that they owe their origin to the organized 

 kingdoms of nature, efpecially to that of vegetables, which 

 hitherto has been fupported only by prefumptive proofs, feems 

 now, in a great meafure, to be confirmed, although the caufes 

 which operate thefe changes on vegetable bodies are as yet 

 undifcovered. 

 They arc not Many facls indicate, that time alone does not reduce ani- 



aJone! * mal or vegetable bodies to the ftate of foflils. In this country, 



there are numerous examples of large quantities of timber, 

 (even whole forefts) which have been fubmerged prior to any 

 tradition, and which neverthelefs completely retain their lig- 

 neous characters.* Other local caufes and agents muft there- 

 fore have been requited, to form the varieties of coal and 

 other bituminous fubfiances. In fome inftances (as in the 

 formation of Bovey coal), thefe caufes feem to have acted 

 partially and imperfectly, whilft, in the formation of the 

 greater part of the pit coals, their operation has been exten- 

 sive and complete. 



In the pit coals, the mineral characters predominate, and 

 the principal veftige of their real origin feems to be bitumen ; 

 for the prefence of carbon in the ftate of oxide, cannot alone 

 be confidered as decifive. 



Bitumen, therefore, with the exuviae and impreffions fo 

 commonly found in the accompanying ftrata, muft be more 

 immediately regarded as the proofs, in favour of the origin of 

 pit coal from organized bodies ; and, confidering the general 

 facts which have been long obferved, together with thofe 

 lately adduced refpecling the Bovey coal, and the fubftance 

 which is found with it, we feem now to have almoft unquef- 



* Phil. Tranf. for January, 1671. Phil. Tranf. Vol. XIX. 

 p. 526. Ibid. Vol. XXII. p. 980. Ibid. Vol. XXIII. p. 1073. 

 Ibid. Vol. XXVII. p. 298. Ibid, for 1799, p. 145. 



tionable 



