4. 



^. HUTTONIAN THEORY. 301 



I 



^^ tk ^' Arran, exhibit thefe veins in ailonifliing varie- 



'^%i'^ ty and abundance. The ftrata are, in ma- 



■4Ce ^ ny inftances, fo reticulated by the veins, and 



' ^i ''' interfedled at fuch fmall d? (lances, that it 



:^^ A feems neceflary to fuppofe, that the fiffures 



reii 



) 



in them were hardly fooner made than fdied 



rm ' "P* ^^'^^ ^t ^^^ft is true, if the veins are to 



^^\ be accounted all of the fame formation; and, 



/ i^\ in the greateft number of inilances by far, 



^^M there is no mark of the one being pofterior to 

 ^^^. the other. 



°^f«i{i:: 26s. The induration of the fides of thefe 



*f"(i5l! veins, in fome cafes, has been fuch, that the fides 

 termi! .! have become more durable than the vein itfelf ; 

 ej fo that the whinftone has been worn away by 



r. 



1 



J 



& 



the wafhing of the waves, and has left the fides 

 braereii landing up, with an empty fpace, like a diteb, 

 thefe: t>etween them. One of thefe I remarked on the 



fouth fide of Brodick Bay, in Arran, which, 

 where it met the face of an abrupt cliff, was not 

 lefs than forty or fifty feet in depth. 



266. I fhall pafs over whatever argi 

 might be drawn in favour of our fyftem, from 

 the llcnder ramifications of the veins, and the 

 varieties of their fizes, from a few inches to ma- 

 ny fathoms in diameter, and alfo from the con- 



It tM'' 





'J 





me 



e 1'' nedlion which they often appear to have with the 



\cm'. great tabular malTes of bafaltes.; and (hall only 



add 



