L. A. Necker de Saussure Voyage en Ecosse. 199 



of Clyde, comprising Bute and Arran, the feldspar porphyries 

 the clink-stones, the veins of pitch-stone, and the accompany- 

 ing feldspar basalts seem to predominate ; notwithstanding 

 . which, veins of green-stone and masses of genuine basalt occur. 

 Lastly, the two principal trap districts of the Hebrides, those of 

 Mull and Sky present scarcely any other thing than great 

 masses of basalt with compact feldspar ; amygdaloidul basalt, 

 basaltic wacke, with a small quantity of obsidians, green-stones, 

 and porphyries. 



On the two banks of the Firth of Forth, the crests of green- 

 stone, which may be considered as portions of veins, rise every 

 where above the coal-beds, as at Salisbury-craigs ; on the sea- 

 shore between Leith and Queen's-ferry on the south-side ; and 

 the islands of Inch-Colm and Inch-Garvey at Norlh-Queen's- 

 ferry ; and at Aberdour, Burntisland, and on the north shore. 

 In this same district, the green-stone occurs also under the 

 evident form of veins of a great length. From these large 

 veins much narrower ones proceed, which spread themselves 

 in the neighbouring beds. According to Mr. Necker, it is 

 similar narrow or thin veins which by sections, perpendicular 

 to their direction, exhibit in the quarries those deceitful ap- 

 pearances of irregular insulated masses of green-stone, in the 

 middle of the coal strata. " Mr. Jameson," says the Genevese 

 geologist, " has described and figured these pretended insulated 

 masses, in the first volume of the Edinburgh Philosophical 

 Journal. He endeavours to derive from them a support to his 

 new system of contemporaneous formations, to which he ap- 

 pears to give every day more extension. As soon forsooth 

 as a series of difterent rocks presents some obscurity in its 

 position {gissemenf], some appearances in their relations with 

 each other which cannot be easily explained on the Neptunian 

 hypothesis, he cuts through the difficulty slap-dash, by de- 

 claring all these rocks to be of contemporaneous formation. It 

 is thus according to him that we find in the county of Caithness, 

 masses of syenite, granite, lime-stone, conglomerate, and sand- 

 stone, all simultaneously formed." [Edinburgh Philosophical 

 Journal, Vol. II., p. 377). " At the Cape of Good Hope, gneiss, 

 clay-slates, rocks of quartz, and of granular quartz, improperly 

 called red sand-stone, are traversed by granitic veins. Conglo- 

 merates and sand-stones, probably secondary, are close by, 

 but the superposition and relations of these rocks to one 

 another appear sufficiently obscure, yet every thing is quite 

 clear to Mr. Jameson, who regards all these rocks as formed 

 simultaneously in tlie position where we now find them." 

 (Ibid, Vol. I., p. 283). 



Lastly, the pretended insulated masses of green-stone occur 

 in the hill on which Edinburgh stands, and they are surrounded 

 by beds of coal sand-stone, with palm impressions, which 



