11 



ILLUSTRATIONS OF THE 





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granite or with gneifs. The primitive flrata, in 

 Dr Hutton's theory, comprehend, befides gneifs, 

 the micaceous, chlorite, hornblend, and fili- 

 ceous fchiflus, together with flate, and fome 

 other kinds of argillite ; to which we muft 

 add, ferpentine, micaceous limeftone, and the 

 greater part of marbles. Thefe are moftly 

 diftinguiflied by their laminated ilrudlure, by 

 having their planes much elevated with re- 

 fpe<5l to the horizon, and by belonging more 

 to the mountainous than the level parts of the 

 earth's furface. They rarely contain velli- 



^ 



ges of organized bodies ; fo rarely, indeed, that 

 they were called primitive by the geologifts who 

 flrft dillinguifhed them from other rocks, on the 

 fuppolition of their being part of the prime- 

 val nucleus of the globe, which had never un- 



but this, 



I believe, has now almoft ceafed to be the opi- 

 nion of any geologift *. The Neptunifls hold 



the rocks, here enumerated, and alfo granite, to 

 be produced by aqueous depolition ; but main- 

 tain them to be in the ftrid:ell fenfe primeval, 

 and of a formation antecedent to all organized 



r 



bodies. 



8. In oppolition to this, Dr Hutton maintain- 

 ed, that the primary fchiftus, like all the other 



ftrata, was formed of materials depofited at the 



bottom 



dergone any change whatfoever ; 



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* Note hi. 



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