NOME IV. TUFO. 411 



" From the same fissures. 



" No. XXVI. A bard lava, the base of which 

 contains many small laminae of felspar and 

 grains of volcanic chrysolite, coloured by fire, 

 and some pretty large clusters of the same kind 

 of chrysolite. 



" From the current of lava which flowed to- 

 wards Bronte. 



" No. XXVII. A hard, grey, and dullish lava, 

 with abundance of laminae of felspar, of greater 

 size than in the preceding specimen ; they are 

 enveloped in the base of the lava, as well as 

 some crystals of prismatic schorl, and some yel- 

 low and greenish chrvsolites. 



" From the same stream of lava as the pre- 

 ceding. 



" The different specimens of lava I have de- 

 scribed, show us the nature of the various kinds 

 of primitive stone, which constitute the base of 

 Etna ; they demonstrate also that the rocks, 

 which enter into the composition of these erup- 

 tions of lava, undergo little change from fire ; 

 and that, in the last eruption, the granitoid schist 

 had been chiefly attacked*. 



* " From the indications of the Commander Dolomieu, who has 

 discovered in the Neptunian mountains (or those of Peloro) all the 

 primitive rocks found in the various lavas evolved from Etna, I have 

 myself made a large collection of them j these I have also compared 



