VICINITY of EDINBURGH. 423 
tend my obfervations fo widely, as to embrace the facts refpect- 
ing thefe rocks. One remark I fhall, however, hazard in 
this place, refpecting an eflential difference between veins of 
granite and thofe of greenftone. The former feem to be of 
fimultaneous formation with the great body of that rock, to 
which they may generally be traced, and, fo far as I have hither- 
to obferved, are never found to cut it. Veins of greenftone, on- 
the other hand, I have never feen connected with the great beds 
of that fubftance; they traverfe thefe juft as they do every 
other kind of rock, and confequently are in all inftances of a 
pofterior formation. I am aware, that thefe ideas are ve- 
ry much at variance with certain received opinions. I there- 
fore wifh to be underftood as fpeaking folely upon my own 
experience.. : 
I HAVE now to mention the well-known included mafs of . 
fandftone. Along the edge of the ftrata, a number of inftances 
occur on Salifbury Craig, affording the moft unequivocal marks 
of difturbance; but it prefents only one example; of a mafs to- 
-tally enveloped in the fubftance of the greenftone *. 
"Turis {pot has been the fcene of much controverfy, between 
contending geologifts. While the Huttonian confiders it as a 
moft incontrovertible proof of violence and of heat, the Werne- 
rian contends, that there is nothing in the leaft extraordinary in 
the appearance, and afferts, that the fuperficies of the apparently 
included mafs, is no. more than the fection of fome part of the 
ftratum, which, if traced, would be found to connect with the 
reft; that it had been enveloped in the fluid menftruum of the 
green{tone, when in this elevated pofition ; and that the rock be- 
ing 
* Since this paper was fent to prefs, others have been obferved in different 
parts of the rock. 
