4^4 



Upon this point, our lively Frenchman talks with much more 

 plegfantry, than our grave northern phiiofophers ; he fays, " as to the 

 " aftion of the aqueous fluid upon the glowing bafalt, as to the ter- 

 " riblc combat, which muft arife from the contaft of water and fire, 

 " when matters in fufion circulate at the bottom of marine gulphs, I 

 " muft confefs, that this part of natural hiflory has, as yet, made a 

 " very fmall progvefs ; that we are unprovided with accurate obferva- 

 " tions on the fubjecV. Nature fecms, on this occafion, difpofed 

 " to cover herfelf with an impenetrable veil, or rather fcience has ad- 

 " vanced too little, and the code of fafts is too new, to enable us 

 " to folve demonftrabiy ce beau probleme."* 



The agents employed by thefe gentlemen, are totally different ; 

 M. St. Fond prevents his calcareous fubflances from calcining by the 

 help of the aqueous fluid, while Dr. HuUon (as will appear) performs 

 the very fame operation, by incalculable preiTure. (Miner, des volcans, 

 chap. 13.) 



Dr. Hiiiion (page 225) lays it down as a truth not to be queftioned, 



" That the ftrata formed at the bottom of the fea, are to be con- 

 " fidered, as having been confolidated, either by aqueous folution and 

 " cryftalization, or by the effeft of heat and fufion." 



He then proceeds to prove, that they were not confolidated by aqut- 

 ous folution, a queftion with which I have nothing to do ; but where 

 he makes ufe of an afl"ertion pofitively contradifted by fa^s within my own 

 knowledge, I think I am not at liberty to fupprefs them, though I do 

 not take any part in the queftion. 



Dr. Hutton fays, (page 227) " it is inconceivable how thefe mafl"es 



" fliould be abfolutely confolidated, without a particle of fluid water 



'■' in their compofition." 



^ No 



* That the ingenuity of modern chemifts has difcovered preffure to be a powerful 

 agent, I well know ; as to " the wonderful fuccefs with which Dr. Hullon has applied it, 

 " to explain the moft myfterious phienomena," I cannot concur willi Mr. Playfair. 



