various parts of Scotland. 409 



the limestone. The uppermost part of this ridge seems to consist 

 of one great uninterrupted bed of limestone, some hundreds cf 

 feet in thickness, or rather, of an accumulation of beds ; well marked 

 horizontal lines being observed to extend in a parallel direction along 

 the precipice. It is also completely traversed by perpendicular fis- 

 sure§. 



Below this great mass a bed of quartz or sandstone, of consider- 

 able thickness, is to be seen running parallel with, and separating 

 the incumbent from a similar subjacent body of limestone. I did 

 not observe whether this alternation Is carried further, but it is 

 probable that it might be discovered in some other parts of the ridge. 

 The limited extent of my investigation also prevented me from 

 determining the position of the limestone relative to the great 

 sandstone or quartz formation ; whether it lies upoft the sandstone 

 which rises to the south of it, and under that which rises to the 

 north, or whether it Is a partial deposit, occupying the valley alone, 

 and incumbent on the whole mass. The examination of an ex- 

 tensive tract of very difficult access, would be requisite to decide 

 this question, as well as to ascertain the magnitude of its extent, and 

 the nature of the limits by which It is bounded. Yet, the appear- 

 ance of a quartz bed alternating with it, renders it probable that It Is 

 also interposed among some of the larger masses. The beds which 

 I have described are elevated to a considerable angle, and although 

 in some places their section forms a continuous and even line, in 

 others they are curved and broken, and tossed about to such a 

 degree, that their stratified position can scarcely be perceived. The 

 stone Itself is a dark grey or nearly black bituminous limestone, of an 

 earthy aspect, and minute granular fracture, smelling offensively when 

 rubbed. I did not any where observe animal remains in it. In many 

 places it Is fissured into small fragments, the intervals of which 



Vol. n. 3 f 



