in October, 1823. ISl 



careous or other strata which once covered the site of Vesu- 

 vius, variously affected by repeated and continued exposure 

 to the influence of the mysterious and ever-varying pheno- 

 mena which take place in the fiery depths of the volcanic 



laboratory. 



In a chemical light, the eruption of last October distin- 

 guished itself from all preceding ones by the excessive abun- 

 dance of sulphur deposited by the vapours evolved from the 

 lava it produced. The various chemical products of these 

 fumarole have been collected and analyzed, with great care, by 

 Messrs. Monticelli and Covelli, who have been closely occu- 

 pied, since the date of the eruption, in preparing for the presS 

 a descriptive work on the subject, which will probably be out 

 in a few weeks, and, I have no doubt, will prove extremely 

 interesting. If I can discover any method of forwarding it to 

 England, I will despatch it as soon as published. In the 

 mean time, perhaps, these brief remarks may help to gratify the 

 curiosity of the readers of this Journal. 



Perhaps, it is worth while to mention, that the appearance of 

 the actual crater of Vesuvius offers a complete confirmation of 

 the opinion I was led to adopt in France, as to the identity of 

 the circus or upper basin of the Dordogne, in the Mont D'or, 

 with the principal crater of that extinct volcano. 



Were the fires of Vesuvius to be in turn extinguished, and 

 its activity cease from this moment, (a circumstance by no 

 means impossible,) a few centuries would probably see the in- 

 terior of the crater laid open by a valley, through which the 

 waters accumulating at its bottom, would discharge themselves 

 into the sea ; and in this event, the resemblance to the upper 

 circus of the valley of the Dordogne, would be most strikingly 

 exact. The lofty and precipitous rocks encircling each basm 

 offer the same general characters ; equally ragged, shattered, 

 and calcined, they are composed alike of conglomerate beds, 

 alternating with strata of lava, prismatic or not, and mtersected 

 occasionally by vertical dikes. From the margin of these 

 cliffs, in either case, the outer flanks of the cone shelve down- 



