He admits, it is only thirty feet wide; but, he says, it 

 must enter fo7't avant dans le profondeur de terre, to judge 

 by the profile of the causeways it has produced ; in other 

 words, it should have been much greater. In another 

 place,- he admits its apparent diameter, to be but five or 

 six feet; 'Of leeisf, we can only ^ see so much : scoriae conceal 

 the rest, which ought to be ten times as great. 



Is it not now plain, that a current, of such trifling 

 ■dimensions, was totally insufficient, to produce the effects 

 Mr. St. Fond ascribes to it? Must we not, therefore, 

 when we admit his volcano, give up his current of lava, 

 as untenable? And this exactly corresponds with the ob- 

 servations, made on the spot, by my ingenious and learned 

 ■friend. Dr. Perceval, Professor of Chemistry, in Dublin 

 College ; who assured me, that the mountain, De la Coupe, 

 was an extinguished volcano; but that what Mr. St. Fond 

 called a current of lava, was merely a ravine, the effect of 

 some torrent. 



Lest, however, I should be blamed, for contradicting a 

 gentleman, who visited the place, which 1 never did, I give 

 up the point, and admit Mr. St. Fond's current of lava; 

 " which, descending the hill, enveloped some of the prisms 

 of the pave, of which the whole country, by his own ac- 

 count, is formed; and which obviously existed there, before 

 the volcano erupted; as did Mr. Desmarest's prisms and 

 pillars, in Auvergne. 



I have dwelt upon this fact; both because it has been 

 often quoted with much triumph, and, also, because it is 



the 



