GEOLOGY OF THE CAMPSIE HILLS. 43 



the mass, but could be easily scratched by the 

 nail. This example is drawn from classic ground : 

 I discovered it in the vicinity of ancient Car- 

 thage, where debris now only mark the former 

 site of that great and important city. 



Those geologists, who, upon the other hand, 

 assert, that columnar forms are not produced by 

 volcanic operation, must surely have never visited 

 a real volcanic region. Proofs of this form having 

 taken place in consequence of volcanic agency, 

 are to be seen around the sites of almost every 

 yolcano where lava has been erupted. I shall, 

 however, not now take up the time of this So- 

 ciety longer, than by giving one of the many ex- 

 amples that I could bring forward in proof of 

 this assertion being well founded ; and this ex- 

 ample I shall draw from a subject which cannot 

 bear a dispute as to its being of volcanic origin i 

 and which, according to my opinion, will alone 

 prove decisive. 



The Eolean or Lipari Islands, are clearly as- 

 certained to be of volcanic origin ; the greater 

 part of them have been visited by men of science, 

 who, from their geological knowledge, were per- 

 fectly adequate to ascertain of what materials 

 they are formed, and to describe those materials 

 scientifically. Felicuda, is one of the most west- 

 ern of this group of islands. It is generally 

 reckoned from eight to nine miles in circum-- 



