87 



most fertile country in the world on all sides of it, to 

 the extent of about fourteen or fifteen miles, where the 

 woody region begins. It is composed almost entirely 

 of lava, which, after a number of ages, is at last con- 

 verted into the most fertile of all soils. 



Every eruption generally forms a new mountain. As 

 the great crater of ^Etna itself is raised to such an enor- 

 mous height above the lower regions of the mountain, it 

 is not possible that the internal fire raging for vent, even 

 round the base, and no doubt vastly below it, should be 

 carried to the height of twelve or thirteen thousand feet 

 to the summit of jEtna. It has therefore generally hap- 

 pened, that after shaking the mountain and its neigh- 

 bourhood for some time, it at last bursts open its side. 

 At first it only sends forth a thick, smoke and showers of 

 ashes, that lay waste the adjacent country: these are 

 soon -followed by red-hot stones, and rocks of a great 

 size, thrown to an immense height in the air. The fall 

 of these stones, together with the quantity of ashes dis- 

 charged at the same time, at last form one of these 

 spherical and conical mountains. Sometimes this pro- 

 cess is finished in the course of a few .days : sometimes 

 it lasts for months, which was the case in the eruption in 

 l66y. In that case the mountains formed are of a 

 great size, some of them are not less than seven or 

 eight miles roimd, and upwards of one thousand feet in 

 perpendicular height : others are not more than two or 

 three miles round, and three or four hundred feet high. 



After the new mountain is formed, the lava generally 

 bursts put from its lower side; and bearing away every 

 thing before it, is for the most part terminated by the 

 sea. This is the common progress of an eruption ; 

 however, it sometimes happens, though rarely, that the 

 lava bursts at once from the side of the mountain, with- 

 out all these attending circumstances; and this is com- 

 monly the case with the eruption of Vesuvius, where the 

 elevation being so much smaller, the melted matter is 

 generally carried up into the crater of the mountain, 

 \vhicli then discharges showers of stones and ashes from 

 the mouth of the volcano, without forming any new 



