HUTTONIAN THEORY. 



197 



ii 



\ 



iP. 



i 



ency of pitch. TRe manner, therefore, in which 



petroleum exifts in the ftrata, is very conliftent 



with the idea of its having been introduced in 



the form of a hot vapour. 



Even amber appears to have fome relation to 



c 



oal. 



It is found in the unconfolidated earth in 



Pruffia and Pomerania ; but I am not fore whe- 

 ther this earth is travelled or not. In the fame 

 earth where the amber is found, there is often a 

 mixture of coaly matter, which burns in the 

 fire ; it is apparently fibrous, and has been con- 

 fidered as a kind of foffil-wood *. 



Thefe cii^umftances make out a connexion 

 between the purer bitumens and ordinary coal ; 

 but do not, it muft be acknowledged, eftablifh 

 any thing with refped: to the more immediate 

 relation, fuppofed in this theory to exill between 

 them and blind-coal. It is probable, indeed, 

 that, to difcover any fads of that kind, the na- 

 tural hiftory of both fubftances muft be more 

 carefully examined ; the natural hiftory of blind- 

 coal, in particular, has hitherto been but little 

 attended to. 



I 



175. A fad is mentioned by Mr Kirwan, which 

 muft not be regarded as lefs valuable for being 

 adverfe to this theory. It is, that neither pe- 

 troleum, nor any foffil bitumen, is found in the 

 vicinity of the Kilkenny coal, as might be ex- 



N3 



ped:ed. 



f Buffon, Hift. Nat. des Mineraux, torn. ii. p. 5 



