( ^7^ ) 

 deny the poffibility of there havuig been a 

 volcano in fiich places ; but I muft affirrn 

 that thefe indications are equivocal, and, 

 therefore, may be fallacious. It is true 

 that many volcanic products are black, 

 with a colour varying from the blacknefs 

 of iron to a greyifh black. It is equally 

 true that, in a long feries of time, this 

 colour is not loft by many volcanic produc- 

 tions, as appears from fome lavas in the 

 Eolian iHes. But it is likewife true, that 

 in many others the blacknefs dimini(hes in 

 time, and, at length, totally difappears, as 

 we fee in the greater part of the lavas of 

 Vefuvius and Etna, which, though at firft 

 they approached more or lefs to a black 

 colour, have gradually loft that colour, till 

 at laft they have acquired one refembling 

 that of common earth. It is fufficient 

 merely to caft the eye on the recent cur- 

 rents, thofe of a moderate age, and the 

 ^ moft ancient, of thofe tw^o volcanos, to per- 

 ceive thefe fucceffive changes. Every lava, 

 however, though of a recent date, is not 

 black. The colour which is proper to the 



primordial 



