

VOLCANIC PRODUCTS, ETNA. 



275 



Upper 

 Gallerx. 



which protect them from waste ; and in regard to the newer 

 ones, such is the porosity of their component materials, that 

 the rain which falls upon them is instantly absorbed ; and in Recess 6. 

 for the same reason that the rivers on Etna have a subter- 

 ranean course, there are none descending the sides of the 



minor cones. 



# 



♦ 



# 



# 



No sensible alteration has been observed in the form of 

 these cones since the earliest periods of which there are 

 memorials ; and there seems no reason for anticipating that 

 in the course of the next 10,000 or 20,000 years they will 

 undergo any great alteration in their appearance, unless 

 they should be shattered by earthquakes or covered by 

 volcanic ejections." — LyelFs "Principles of Geology," 7th 

 edition, chap. xxv. (H. W. Bristow.) 



233. — Trachyte, with crystals of augite, from the neigh- 

 bourhood of Milo. 



234. 

 1819. 



Titaniferous iron- sand, from the crater of 



235. — Lava, with minute crystals of specular iron, from 



Monte 



236. — Basaltic laya, with mellilite and Thomsonite. 



237. — Specular iron, crystallized on scoriaceous lava, 

 from Monte Rossi. (Eruption of 1669.) 



Monte Rossi is a double cone, rising to a height of about 

 450 feet, about 20 miles from the summit of Etna. It was 

 formed during the eruption of 1669. 



238. — Scoriaceous laya, with crystals of glassy felspar } 

 from below Monte Vituri. 



239. — Sulphur, crystallized on scoriaceous lava, from the 

 interior of the crater of 1819. 



240. — Volcanic ashes. 



241. — Consolidated volcanic, ashes cementing sea 

 shells, from the extinct volcanos south of Etna. 



242. — Basaltic lava, with olivine and a little augite y 

 from the hill of Paterno. 



