on the Mountain Cruacban. 119 



more numerous varieties which did not come under my observation 

 may be found to exist. 



Arriving at the high bridge which crosses the river Awe, the 

 mineralogist will be surprised to meet with a secondary stratum in 

 a situation certainly as unexpected as can well be conceived. A 

 small portion of it only is denuded by the action of the river, and 

 exhibits two distinct beds, the lowermost consisting of the well 

 known red sandstone spotted with white, which occurs near Dumbar- 

 ton, in Arran, and elsewhere, and the uppermost of a coarse grained 

 white calcareous grit. This stratum is elevated at a small angle, and 

 shelves away towards the side of Cruachan as if it was about to dip 

 under the mountain : its junction with the primary schistus is not 

 visible. I could not trace it upwards on the opposite side of the 

 river in the direction of the stratum, although it is probable that 

 from the red colour of the soil some portion of it exists where the 

 road is made. It may be traced a little way down the course of the 

 river, but the ground being much encumbered and difficult to ex- 

 amine, it soon disappears. I attempted in vain to find it on the flat 

 tract at Bunawe, nor did I succeed any where from Tyanuilt to the 

 sea in recovering any portion of this stratum ; the low land being 

 always covered with alluvial matter, and the denuded rocks appearing 

 every where to consist of schist and granite traversed by veins of 

 porphyry^ It affords a remarkable example of a deposit of secondary 

 rock, not many hundred yards square, entangled in the middle of a 

 primary district, and separated, apparently by many miles, from any 

 other similar rock. I shall hereafter however attempt to give a 

 general sketch of the connection of Cruachan with the surrounding 

 country, when the recurrence of the same circumstance will be de- 

 scribed, which, if it diminishes the surprise at first excited by its 

 solitary and unconnected appearance here, increases its general in- 



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