238 Notice of Active and Extinct Volcanos. 



able to his candor and to the vigor of his rnind, because he 

 had before published an able and interesting treatise, to prove 

 that basalt, and especially the basalt of Saxony, was of aque- 

 ous formation. 



The volcanic district of France lies upon the river Rhone, 

 nearly in the angle formed by it with the Mediterranean, and 

 covers an area nearly square, of from forty to fifty leagues in 

 diameter. 



We have never visited that country, but the evidence of its 

 volcanic origin exhibited by Mr. Scrope and Professor Daube- 

 ny confirming, extending and giving precision to the observa- 

 tions of many previous writers, leaves not the shadow of a 

 doubt, that the tremendous subterraneous agency of fire has 

 covered this fine country with floods of molten rock ; no more 

 doubt indeed, than that similar events have happened at Vesu- 

 vius, Cotopaxi and ./Etna. 



Being possessed of a fine series of specimens, from this very 

 region, furnished to the cabinet of the American Geological 

 Society by our celebrated geologist, Mr. William Maclure — 

 we sit down with these specimens — with the full descriptions of 

 the authors whom we have just named and with the noble atlas 

 — geological — geographical and picturesque, of Mr. Scrope, 

 illustrating the striking features of this interesting region, and 

 while we feel the fullest conviction that their conclusions are 

 substantially correct, we can easily imagine that we see the 

 floods of lava, pouring from the now quiet and cold craters, and 

 that the skies of France were once dimmed by the clouds of 

 volcanic ashes, as those of Italy are at the present day. 



Craters, regularly formed, often entire, sometimes with the 

 thin and scorified edge of the lip in fine preservation, and oc- 

 casionally of vast dimensions ; here, black, rugged and scathed 

 with fire, there, overgrown with trees and there, filled with 

 water forming lakes ; currents of lava, lying where they flow- 

 ed from the crater, or where they burst from the side or foot of 

 the ruptured mountain, extending many miles and many 

 leagues, traceable directly to their parent mountain, winding 

 along the gorges and the sinuosities of the vallies, now and 

 then diverted from their course by rocks, hills and other obsta- 

 cles ; sometimes damming up rivers, whose courses they have 

 crossed or obstructed, and thus forming lakes of considerable 

 dimensions ; exhibiting all the varieties of lithoid lava, from 

 that which is compact" and rock-like, to that which is porous 

 and vesicular in an incipient or in a prevailing degree ; crown- 



