

NOME VII. VOLCANIC INTRITE. 



tains but few fragments of augite or pyroxene, 

 and seems to be an assemblage of leucites, the 

 superficial crystalline lustre of which, having 

 been impaired by decomposition, makes it re- 

 semble variolite in its exterior. Many detached 

 masses of this current have fallen to the bottom 

 of the valley. Each fall of matter brings down 

 calcareous stones, mica, mixtures of felspar, and 

 idocrases. The lava of 176?> which threatened 

 the villages of La Barra and Saint Jorio, dis- 

 charged itself into this valley, which it filled to 

 a certain height, and afterwards flowed, spread- 

 ing itself, to the plain. As it is already covered 

 by the crumblings from the flank, in order to 

 examine it the inquirer must repair to the plain 

 of Saint Jorio, in the neighbourhood of the cha- 

 pel of Saint Vito. Its grain is crystallised but 

 fine, and oftentimes so close and compact as to 

 be nearly equal to petro-silex. It contains many 

 small crystals of pyroxene, and fragments of 

 leucite, which is rarely found in its perfect form 

 of crystallisation .... 



" The lava of La Scala passes beneath the gar- 



1 La Scala, 



den of La Favorita. It is of the colour of ashes, 

 whitish, and of a crystallised grain. It contains 

 many crystals of pyroxene, few of leucite, and 

 small pieces of felspar, in groups in its cavities. 

 This lava, where it is hewn on the sea-shore near 



% 



Lava of 

 ./a Scala. 



