G. P. Scrope on Craters, and the Liquidity of Lavas, 359 
northern and outer side of the cone. Tt would be, therefore, in 
€xact accordance with the habit of this voleano (as of yoleanic 
mountains in general), if, after some further period either of qui- 
€scence or of moderate activity, the entire cone of Vesuvius 
should be blown up by a more than ordinarily violent paroxysm, 
and the crater of Somma itself reformed. 
With this well-authenticated history of the mountain within 
our knowledge, would it not be wholly unphilosophical to deny 
(except upon such grounds of impossibility as have never been 
adduced) that the larger containing crater in the case of Vesu- 
Vius (and the argument applies to other similar volcanic moun- 
tains) had the same origin as thasmaller ‘contained ones; and 
that the external cones were produced in the same manner as 
the internal, and similarly constituted ones? And therefore 
those who refuse to believe the former to be of eruptive origin 
of elevatory expansion by a single shock. Obviously, it ought 
to follow, th i 
that the whole is an ocular illusion; at least, that the lava- 
gmentary matter which, during equally long periods, we see 
thrown dip ita the crater and falling on the uses of the cone, 
do hot, even in the lapse of ages, add to its bulk or tend bj 
their frequent.repetition to compose the substance of a voleanic 
ar 
of formation going on in some instances before my eyes, I think 
tion and elevation, by means of intrusive dykes and earthquake 
I 
(Zo be concluded.) 
