MINERALOGY OF THE PENTLAND HILLS. 169 



ciirs in small silver- white scales. I could not dis- 

 cover that these minerals were connected together 

 by any basis ; on the contrary, they appear to be 

 associated in the same manner as the felspar, quartz, 

 and mica are in granite. Is it therefore to be con« 

 sidered as a rock deposited from a state of chemi- 

 cal solution ? Sandstone, in a general point of 

 view, may be considered as a continuation of the 

 Granite series, and might be denominated Floetz 

 Quartz-rock, It sometimes contains cotemporaneous 

 portions of floetz-limestone, thus forming a kind of 

 arenaceous limestone-conglomerate. The lime- 

 stone even appears to form thin and short beds in 

 the sandstone, as is the case in the sandstone rocks 

 above Habbie's How. The limestone is of a grey 

 colour, the fracture is foliated, and it includes co- 

 temporaneous calcareous spar, and variously shaped 

 concretions of compact limestone. Limestones of 

 this kind have been described as brecciated stones, 

 or as composed of fragments : thus, the transi- 

 tion limestones often exhibit this brecciated cha- 

 racter, and Brochant, in his valuable paper on 

 Transition Rocks, in the Journal des Mines for 

 1808, maintains, although unsuccessfully, that 

 these limestones are truly brecciated. 



Some varieties of the sandstone are not unlike the 

 grey-wacke which occurs near Habbie's How ; 

 and consequently closely resemble the fine granular 

 yarieties of conglomerate. It is distinctly stratified j 



