I 



of 



f, 



% 



artf 



2D 



1) 



m 



i 



fail 



i 





i^t'. 



«i 



;ii 



fi 



/ 



> 



HUTTONIAN THEORY. 



^57 



carried into the Tea, and fpread out over its bot- 

 tom, though all thefe are neceffary pojlulata in 



One 



can 



his theory of the formation of coal, 

 be at no lofs about eftimating the value of a 

 fyftem, in which fuch grofs inconfiftencies make 

 a necelTary part. 



144. The quantity of hornblend and filiceous 



fchiilus, neceflary to be decompofed, in order 



P 



th 



coal ftrata prefently exiHi 



o 



IS 



enormous, and would lead to an eftimate of what 

 is worn away from the primeval mountains, far 

 eeding any thing that Dr Hutton has fuppo- 



fed 



It 



Mr Kirwan 



never at all 



mbarralTed ab 



preferving a fimilitude be 



tween nature as (lie is now, and as Ihe was here 

 tofore, lays it down, that the part of the prime 



/ 



mount 



which is worn away, concained 

 much more carbon than the part which is left 



behind 

 fition ; 

 tions a 



This, 

 id fin 

 fo ea 



h 



v/ever, is an arbitrary fuppo 

 in this fyftem, fuch fuppofi 



eafily admitted, why may we not 

 conceive, in the primeval mountains, a more 



copious fource of carb 



blend 



or filiceous fchift 



matter than 

 We have b 



h 



It to 



imagine, that the diamond exifted among thefe 

 mountains in fuch abundance, as to conditute 



la 



rge rocks. 



Thi 



is fi:one being made up of 



pure, or highly concentrated carbon, the ada- 



mantine fummits of a 



fingle ridge. 



by their 



decompofition, 



