86 



forms by crystallization; as the dift'ereiices between them, 

 and all known crystals, are numerous and essential. 



I should now (as I do on similar occasions) proceed 

 to shew, that, notwithstanding Dr. Hamilton's plausible 

 arguments, a priori, the abrupt promontories of Antrim 

 (whose uncommon beauties, as he tells us, page 147, second 

 part, resemble what will be exhibited at the grand 

 opening of his vast laboratories of nature) Avere not formed 

 according to the principles of this theory. 



But, as Dr. Hamilton has not given us any account 

 whatsoever, of the volcauos, in whose craters the moun- 

 tain of Dunmull, the mountain of Croaghmore, Fair-Head, 

 towering Tnagnificently, and the lofty cliffs of Magilligan, 

 were formed; (and, to their summits, they are all composed 

 of columnar basalt, by his own account;) I have no ma- 

 terials to proceed upon; and must, therefore, limit myself 

 to one general argument, applicable to all other volcanic 

 countries, as well as to our own. 



The basalts of Auvergne are arranged in plusieiirs etages, 

 according to Mr. Desmarest. Mr. St. Fond applies the 

 same phrase to Vivarais, and says, they were foimed a 

 diverses reprises. The account of Sicily is similar; and, 

 with us, they are invariably disposed, in successive, dis- 

 tinct strata, Avhich never could have been the result of 

 fusion, in the crater of a volcano; as such an operation 

 necessarily would have reduced them to one mass, one 

 stratum. 



PART 



