AND THEIR MEETING WITH GRANITE, 91 



the foot of Mount Etna, are possessed of that same character. 

 M. Dolomieu considers these and others as having been 

 covered by the sea. 



Other unstratified substances would attain, in a liquid 

 state, to positions less and less elevated, as they were more 

 and more refractory ; and the granite would be the soonest 

 congealed, being the least fusible of the whole set. In 

 any of these cases, when the opening above was stopt by 

 congelation, the force from below being irresistibly power- 

 ful, the liquid, as we have said, must have found room for it- 

 self among the strata. This must have been done in one of 

 two modes. 



Either, 1st, when the strata were in a hard and inflexible 

 state, in which case, the liquid must have forced itself be- 

 tween stratum and stratum, by flowing horizontally among 

 them, by which means an arrangement would be produced, 

 similar to that of great part of the group in this neighbour- 

 hood, consisting of Arthur's Seat and Salisbury Craigs, as well 

 seen from the south-west, where thick beds of uniform basal- 

 tic matter, emanating on both sides from the vast massive 

 block in the middle, which rises highest of any, are interposed 

 between thin beds of freestone, lying parallel to each other, 

 and inclined to the horizon at an angle of about thirty de- 

 grees. 



Or, 2dly, where the strata were soft and pliable, and pos- 

 sessed of considerable toughness. In this case, they would 

 yield on both sides, so as to allow the vein to become wider 



M 2 and 



in the predicament ascribed to it by Dr Hutton, when exposed to the same heat 

 under a sea whose pressure is equal to that force. 



The fusions, then, which have taken place in my experiments, confirm Dr 

 Hutton's theory, in so far as it depends upon the action of heat on limestone. 



