AND THEIR MEETING WITH GRANITE. 105 



sion, then, is irresistible, that the granitic mass of Lauren is 

 posterior in formation to the killas which lies above it. This 

 admits of no other rational solution, but by supposing, as Dr 

 Hutton has done, that the granite, in a liquid state, has flow- 

 ed in its present position, and that emanations from that li- 

 quid penetrating into the rents of the strata, have formed the 

 veins. 



The same general facts which have been observed with re- 

 spect to the granite of Lauren, and the district of which it 

 makes a part, occur also in the other two granitic masses of 

 Galloway, as I have found by a particular examination of their 

 junctions with the strata. 



I was convinced of this as to the mass which crosses Loch 

 Doon, by a circuit which I made of that mass in 1807, accom- 

 panied by Mr Jardine of this Society. In the island upon 

 which the Castle of Doon stands, a fine example occurs of an- 

 gular fragments of killas, included in the granitic mass near 

 the junction. The dressing which this stone has received 

 from the hand of nature, renders this very conspicuous, as I 

 shall have occasion soon more particularly to state to this So- 

 ciety. 



I have at different times, though not with the same regula- 

 rity, examined various places, where the third granitic mass 

 in Galloway, of which the Mountain of Criffel makes part, 

 meets the surrounding strata ; and I have seen dikes of granite 

 near the junction, and other circumstances leading to the 

 same conclusion, particularly on the sea-shore, at a place 

 known by the name of the Needle's Eye, which approaches to 

 the granite boundary ; and also on the side of Criffel, which 

 lies directly opposite. 



According to a rough computation, each of these three 



granitic masses occupies a space of about six miles by four. 



' Vol. VII. ' O Their 



