DOMAIN I. SIDEROUS. 



bastions. The columns reunited by their sum- 

 mits, as into one head, enlarge according to their 

 length. 



" Scattered prisms and walls of prismatic lavas 

 may also be found in many other places , form- 

 ing, as I have already mentioned, a kind of belt 

 around the skirts of Etna. Don Joseph Gioeni, 

 whom I have formerly celebrated, is occupied 

 with an elaborate description of the prismatic 

 lavas of the volcano -, and he will add prints 

 which can alone express the variety of their 

 forms, and the manner in which they are 

 grouped*/' 



If these representations be exact, they would 

 certainly induce us to believe that prismatic 

 basaltin is the product of volcanic fires; and an 

 admirer of nature would willingly embrace a 

 new and important discovery, which would afford 

 greater variety to his views, and more striking 

 topics for his contemplation. With regard to 

 the British dominions, in particular, a volcano, 

 even extinct, might be regarded as a grand and 

 curious acquisition. The great number of vol- 



* Dolomieu, Etna, p. 455. It must not however be forgotten 

 that, p. 1Q2, he allows that all these columns present small pores, 

 visible by a lens; nay, p. 180, he regards all lavas as compact which 

 contain spaces of some inches without pores. But he might say, 

 as compactness is owing to refrigeration, that, in the cold and moist 

 regions of the north, lavas are more compact. 



