464 



DOMAIN XII. VOLCANIC. 



ceived their analogy. These last are composed 

 of a white filaceous felspar, which intersects small 

 black and shining crystals of tourmaline." 



HYPONOME III. WITH WHITE FIBROUS VEINS. 



This kind is also found in the Italian volcanoes, 

 but the most beautiful is from New Spain. 



HYPONOME IV. CAPILLARY. 



It appears, from Dolomieu's account of Etna, 

 that this kind sometimes appears in the large ve- 

 sicles of vitreous lava: but that of the Isle of 

 Bourbon, above described, is singularly curious. 



HYPONOME V. GRANULAR. 



Patrin, as above quoted, has described a hill of 

 vitreous sand. 



There yet remain two important distinctions of 

 vitreous lava. 



HYPONOME VI. RESINOUS, 



These have somewhat the appearance of pitch- 

 stone, and Icelandic obsidian sometimes assumes 

 this visage*. They are by many, not improperly 

 classed in the next division. 



* The untranslatable Latin fades is more expressive. 



