BEN-NEVIS. 345 



Jameson, that clinkstone and felspar are nearly 

 allied : because the geognostic position and rela- 

 tions, along with the splintery fracture, of the Ben- 

 Nevis-rock, demonstrate, that it has a strong affini- 

 ty to compact- felspar tinged with hornblende ; 

 and, from a variety of observations made in Ar- 

 ran, Dumfries-shire, and the vicinity of Edin- 

 burgh, Mr Jameson has inferred, that clinkstone- 

 porphyry passes into compact- felspar and clay- 

 stone. The great distinction betwixt the sub- 

 stances of this genus, which belong to the primi- 

 tive and flostz periods, seems to be, that the for- 

 mer in general are more crystalline ; something a- 

 kin to the relation which subsists betwixt primi- 

 tive and transition or floetz-limestone. N 



It is more than probably the external similari- 

 ty here described, which has occasioned Dr 

 Reuss, in his Mineralogical Description of Bohe- 

 mia, to mention clinkstone as belonging to the 

 primitive rocks ; an assertion which does not yet 

 appear to be sufficiently warranted by facts. The 

 clinkstone also, and porphyry- slate, observed by 

 Humboldt in South America, it is not unlikely, 

 may, in many cases, be rocks of a similar descrip- 

 tion and period of formation. " According to this 

 view, as many mountains of an intermediate or 

 considerable height are covered in a manner si- 

 milar to Ben-Nevis, it would be interesting to 

 inquire whether the same circumstance takes 

 place, with regard to any others of this descrip- 

 tion, seen in the range of the surrounding country, 



