ILLUSTRATIONS OF THE 



This fimilarity of 



ftrata that cover the 



mafles of whinftone, to thofe 



ferve 



the 



bafe on which they reft, and again the diflimili^ 

 tudc of both to the interpofed mafs, are fads 



hich I think can hardly 



any expl 



tion, on the principles of the Neptunian theory. 

 If thefe rocks, both ftratified and unftratified, are 

 to be regarded as produdions of the fea, the 

 circumftances would require to be pointed out, 

 which have determined the whinftone, and the 

 beds that are all round it, to be fo extremely 

 unlike in their llrudure, though formed at the 

 fame time, and in the immediate vicinity of one 

 another; as alfo thofe circumftances, on the other 



i ftratified depofites 



hand 



hich determined th 



above and below the whinftone, to be precifely 

 the fame, though the times of their formation 

 muft have been very different. The homo- 



g 



fubft 



mces, thus, placed at a diftance, 

 and the heterogeneous brought fo clofely toge- 

 ther, are phenomena equally unaccpuntable, in a 

 theory that afcribes their origin to the operation 

 of the fame element, and that neceflarlly dates 

 their formation according to the order in which 

 they lie, one above another. 



72. If, indeed, in thefe inftances, the grada- 

 tion were infenfible, as fome have aflerced it to 

 be, between the ftrata and the interpofed mafs, 

 fo that it was impoflible to point out the line 



where 



4 



