6 DESCRIPTION of the 
be found to offer fome very curious and important faéts, parti- 
cularly the gradual elevation, and the final perfect vertical pofi- 
tion of the fand{tone and puddingftone, as well as the rather un- 
ufual manner in which the fecondary and the older ftrata meet 
each other. 
In the feries here to be defcribed, the repeated occurrence of 
rocks of the whm and of the porphyry formation, refpecting the 
origin of which opinions are fo much divided, adds confiderable 
intereft ; efpecially when the form and fituation in which they 
occur, and the condition of the contiguous rocks, are taken into 
confideration. 
In the account which I am now about to give, I fhall endea- 
vour to lay down a fair reprefentation of the facts as Nature pre-~ 
fents them, unbiafled by any of the prevailing theories of cof- 
mogony. I fhall avoid every geological difcuflion whatever, 
leaving it to others to draw thofe conclufions, in relation to 
their own fpeculations, which they fhall imagine the fats to 
warrant. 
In that part of the plains of Kincardinefhire from which I 
take my departure, the native rock confifts of Siliceous Grit or 
Sandftone, which is here divided into an immenfe number of 
beds or layers, of various thickneffes, from one inch to four feet, 
folid ftone. In many places, gravel of various fizes is found im- 
bedded in this grit ; which gravel confifts moftly of water-worn 
quartz, and fimall-grained granites. The colour of the general 
mafs of this grit is a dark-reddifh brown, and in fome few pla- 
ces it fhows narrow lines and dots of a pearl-grey colour. The 
component parts of this grit confift of fmall particles of quartz, 
and {till more minute particles of filvery-luftred mica: thefe owe 
their cohefion in mafs to a martial argillaceous cement, to which 
this rock alfo owes its colour. Thofe lines and dots of pearl- 
grey colour, generally occur in the moft folid and thickeft beds 
of. 
