98 



The peninsula of Kenbaan, near Ballycastle, is the 

 spot, where basalt and limestone come in contact in 

 every possible way. Pieces of limestone of all sizes, im- 

 bedded in the basaltic mass, and similar fragments of ba- 

 salt, dispersed in like manner through the limestone; and, 

 in the precipice above, strata of basalt, and limestone 

 aljternating. Here the opportunities, of examining the con- 

 tact of basalt and limestone, are numberless; and, on 

 every occasion, I found them united solidly; the line 

 of demarcation correct, as if drawn by a pencil; not the 

 least trace of calcination, such as might be expected from 

 the calcareous matter, coming in contact with so glowing 

 a mass, as this theory supposes our basalt to have been.* 



This unexpected circumstance has somewhat embar- 

 rassed the volcanists; who, to account for it, have been 

 driven to various exertions of their ingenuity: but not 

 one of them seems ever to have inquired what was the 

 result, when calcareous matters came in contact with 

 actual lava, as it tlowed. Here an ob\ ious mode presents 

 itself, of deciding the question, whether basalt and lava 

 have a common origin. For, if their contacts with cal- 

 careous matter produce the same effects upon it, mc 

 •have a strong presumption in favour of the affirmative. 



On 



' * The result of my observations, on the contacts of basalt and limestone, 

 perfectly correspond with those of Mr, St. Fond, in Vivarais. (Min. des Vol- 

 cans, chap. 13.) Dr. Hamilton, I admit, saw things in a different point of 

 view ; but, as he does not refer us to the places, where he examined these 

 contact?, 1 cannot bring the point to issue in my country'. 



