NATURAL HISTORY. * t>9 



CHAP. IV. 



OF VOLCANOES EARTHQUAKES THE FORMATION 



OF NEW ISLANDS CAVERNS AND GROTTOES 



BOGS AND FENS CHANGES OF LAND 

 INTO SEA, &C. 



TP 



1 HE burning mountains called volcanoes, include 

 in their bowels sulphur, bitumen, and other materials, 

 which serve as aliment to a subterraneous fire, the 

 effect of which is more violent than that of gunpowder 

 or even of thunder. A volcano is a cannon of a very 

 large size, the orifice of which is often more than half 

 a league. This mouth vomits forth torrents of smoke, 

 flame, rivers of bitumen, sulphur, and melted metal, 

 clouds of cinders and stones, and sometimes it ejects 

 enormous rocks to many leagues distance, which 

 would baffle the utmost efforts of human strength. 

 The combustion is so terrible, and the quantity of 

 burnt, melted, calcined, and vitrified materials which 

 the mountain throws out, is so plentiful, that they 

 enter cities, forests, cover the fields an hundred and 

 two hundred feet in thickness, and form sometimes 

 hills and mountains. The action of this fire is so 

 great, the force of explosion so violent, that its re- 

 action has been known to shake the earth, agitate the 

 sea, overthrow mountains, and destroy the most solid 

 towns and edifices, even to very considerable distances. 

 The natives of Iceland imagine that the roarings of 

 the volcano are the cries of the damned, and its erup- 

 tions the effects of the rage and despair of these un- 

 happy wretches. 



All these phenomena, however, are only the effects 

 of fire and of smoke. In the bowels of mountains, 



