VICINITY of EDINBURGH. 429 
férving, that all the indurated fandftones of this country, con- 
tained more or le{s calcareous matter, while the unindurated 
fpecimens from Ireland, did not afford ‘the flighteft indication 
of that fubftance, when fubjected to the fame feft. 
Beroke I take leave of Salifbury Craig, I muft notice one 
more circumftance, which, fo far as I have hitherto feen, is 
quite peculiar to the fpot. I mean the occurrence, in veins, of 
a fubftance in all refpe&s familar to the indurated fandftones, 
I have juft been deferibing. The firft of thefe I obferved, is 
about thirty paces north of the vein. The ground being cut ’ 
away, in order to fee its connection with the ftrata, it branched 
out like the prongs of a fork, and had the interftice filled with 
a red decompofed fubftance (No. 69.), fimilar to that which 
occurred at the extremity of the included ftripe of greenftone 
in the vein. Where the prongs join, it is about three or 
four.inches wide, and is there, partly compofed of indurated 
fandftone, and partly of hematitic iron-ore and calcareous fpar. 
(No. 70.) Higher up, where the vein is narrower, it is whol- 
ly compofed of fandftone, the fpecimen, No. 71., being the en- 
tire thicknefs of it. ~ Here the grain is finer than at firft, and, 
higher up, it becomes ftill more fo, (No. 72.) It ftill conti- 
wiues to taper upwards, and even when reduced to lefs than half 
an inch, the fubftance retains the ufual afpect ef indurated fand- 
ftone, (No. 73-) This vein rifes about twenty to thirty feet 
into the rock, always diminifhing, and about that height dif- 
appears. I have remarked other veins, alfo containing fub- 
ftances fimilar to indurated fandftone (No. 74.), one was of 
a much larger fize than that above defcribed (No. 75.), but the 
grain not near fo compact, (No. 76.) 
Tuese veins all fet off from the lower furface, and fo long 
as they are of any confiderable thicknefs, the including rock is 
ftained 
