[ ^5 ] 



charaders of both were given, it is probable that other differences., 

 might be perceived. It is only in thefe charaders that any differ- 

 ence can be expeded, as the internal compofition muft be the fame 

 in both. 



Of the remaining artificial whins I can give no account, their 

 external charaders having been omitted ; I cannot however pafs 

 over the general inferences that Sir James deduces from his expe- 

 riments, namely, " that the arguments againft the fubterraneous 

 " fufion of whinftone, derived , from its ftony charader, feem 

 " now to be fully refuted," for not to repeat what has been already 

 faid, that many of them contain fubftances . whofe exiftence is in- 

 compatible with that hypothefis, I muft farther add that the up- 

 right ftate in which many of them exift, for inftance, the bafaitic 

 pillars of Staffa, and of the Giants Caufeway, and of many other 

 countries, the bafis they reft on, fometimes granite, fometimes 

 gneifs, fometimes coal or limeftone, and the total abfence of all 

 figns of the operation of fire, forbid us to. entertain any doubt of 

 their produdion in the moift way. Nay the college of Dublin 

 now poflTeffes fragments of bafaitic pillars in which marine fhells 

 are imbedded; if fuch evidence can be refifted it is in vain to feek 

 for greater. 



Sir James thinks the caufe of the fluidity of lavas, which I 

 formerly fuggefted, as ftrange and inconceivable as that of Citizen 

 Vol. VIII. D. Dolomieu 



