90 



while at jEtna and Vesuvius, he met with burnt matters 

 alone. 



The points of view, in Avhich I shall compare volcanic 

 countries, as described by the most accredited writers, 

 with our basaltic district, so often referred to, by the same 

 authors, are: 



First. The prominent features, and general resemblance. 



Secondly. The different arrangement of the material*, 

 in volcanic, and our basaltic countries. 



Thirdly. Frequent change in the arrangement of the 

 materials, in our basaltic country. 



Fourthly. Striking and radical differences between our 

 basalt strata, and all known cuiTcnts of lava. 



Fifthly. Substances found imbedded in our basalt, and 

 never in lava. 



Sixthly. Difierent effects produced upon foreign sub- 

 stances (particularly calcareous), Avhen coming in contact 

 with basalt, and with lava. 



Seventhly. Divisibility of the mass into regular forms, 

 essential to basalt, but never noticed in lava. 



First. The general and leading features of volcanic 

 countries are admitted to be, isolated inoimtains, generally 

 conic, triLucnted cones, vast craters, Avith currents of lava 

 issuing from them, which may be traced many miles. But, 

 as all writers upon this topic candidly admit, that we 

 have nothing similar in this country; I will not press 

 ^he argument; nor cnciuu-e, whether then' modes, of ac- 

 counting 



