GEOLOGY. 17 



appearance, in being granular, white, and lustrous in colour, and 

 regularly stratified, and in hardness is scarcely distinguishable ; 

 but how different in its susceptibihty of polish and other prac- 

 tical uses. Famed among the ancients in the celebrated quarries 

 of Pares, PenteHcus, and Carrara, their finest and most enduring 

 specimens of sculpture were chiselled from the same family of 

 rocks which claim a parentage with the limestone of the Gram- 

 pians. There are several varieties, differing chiefly in colour, 

 fineness of texture, or as containing imbedded crystals of trerno- 

 lite, sahlite, augite, asbestus, and steatite, whence it derives its 

 unctuous feel and variegated colours, as mottled, striped, and 

 veined by lines of pink, green, and yellow. Its range is nearly 

 co-extensive with that of the quartz formation, being generally 

 imbedded in its mass, or accompanying its outcrop. It is burnt 

 in a great many places into quicklime, but as the concretions 

 have an extreme tendency to exfoliate and separate during the 

 process, by the volatilization of the carbonic acid, it is difficult 

 to preserve its cohesive and other chemical properties, and is 

 accordingly not rendered so applicable to economic uses as it 

 other^vise might be, from the large proportion of calcareous 

 matter contained in it. Preserving the same line of bearing 

 with the quartz-rock, this limestone stretches along the more 

 central parts of the Grampians, and is found in almost every 

 position — in the bottoms of valleys, in the beds of rivers, on 

 the sloping acclivities of mountains, or even caping their ridges 

 and summits. It occurs plentifully on both sides of the Dee, 

 from Ballater towards the Castletown of Bracmar. at which 

 latter place it nearly composes the beautiful hill called the 

 Lion's Face, and thence passes westward by Glen Clunie and 

 the base of the quartz-caped Morven. Appearing at several 

 intervening localities, it descends Gl^iililt, where it is so fre- 

 quently penetrated by the granitic veins of Ben-y-gloe ; and, 

 crossing the river Garry, it may be observed high on the sides 

 of the green hill of TuUoch ; and spreading over the extensive 

 tract southwards to Loch Earn, there are various openings in 



B 



