306 Eruption of Mount Vesuvius in 1828. 



any profit from them. I have thought it more useful to give 

 a vertical section of the great cone, and of the small one pro- 

 duced in the centre of it. 



The section of the cone 'of Mount Vesuvius seen from the interior, looking to- 

 ward the W.N.W. The point at which visiters generally place themselves to see 

 the interior of the crater is at S.S.E. 



1. Bottom of the crater before the eruption. 



2. Scoriae and lava thrown up during the eruption. 

 - 3 Cone formed during the lesser eruption at the beginning of July. 



4. Amphigenous pyroxenic vitrified lava, of the eruption of 1822; in some 

 parts this lava, when it has beneath it smoke vents which exhale fumes, divides 

 itself into coarse prisms. 



5. Stratum of Rapilli (i. e, white pumice) and labbie (dust). 



6. 'Stratum of pumice, and small fragments of scoriae tinged with oxide of iron. 



7. Current of lava Leveitica (greenstone). 



8. Current of lava mixed with pyroxene. Lava of the same kind is found in 

 the veins of the great dike (Fossa Grande}. 



9. Current of lava mixed with pyroxene. It contains (in the geodes) very 

 small crystals of pseudo-nesseline, and a small quantity of breislakite. The frag- 

 ments of this lava crumbles into large prisms, like that at Scala near Portici, 

 which is termed basaltica da Brocchi. 



10. Stratum of rapilli and labbie, impregnated with the fumes which exhale 

 from the fummaioli smoke in that part, with efflorescence and sublimation of 

 sulphur, muriate of soda, and copper. The sublimation makes this spot appear 

 like a cultivated garden. 



11. Current of lava, divided into great prisms. This place is inaccessible. 



12. Rapilli and pozzolana, with globules of the Vesuvian dolomite of Thomson 

 and of lava. These same materials are found far from the external walls, as well 

 on one side as the other. 



