1 84 



ILLUSTRATIONS OF THE 



obfidian 



hich SaiifTure found not to 



5° of Wedge wood 



ceed 



b 



bafaltine, wbich 



quires 140° of Wedgewood, is never melted 



capable, thi 



th 



^tna 



H 



little 



would volcanic heat b 



to 



Carrara 



fFed the fufion of 



m 



excellent auth 



hich, according to the fame 



Id 



req 



a heat of 



up 



f Wedgewood, if this pyrome 



ards of 6300^ 

 r could exter 



ftances does Dr Hutton fuppofe this aftonifhing 



dfof 



And in wh 



circum- 



heat to have 



fted 



d even ft 



to 



ft 



d 



th 



ocean, in the bowels of the earth 



wh 



nor 



; neither a fuffi 

 f combaitible 



:ient quantity of pure air, 

 matter, capable of fuch 



r 



/ 



mighty effeas, can, with any appearance of pro^ 

 bability, be fuppofed to exift ; and, without 

 thefe, fuch degrees of heat cannot even be ima^ 



without flying into the region of chime- 



6^' 



ras. 



ed 



?9 



165. Now, this reafoning is not applicabi 

 Dr Button's hypothefis of fubterraneous heal 



e 



becaufe 

 that v< 



grounded on 



perim 



w 



here 



ry feparation of 



volatile and fixed 



P 



tali 



w 



h 



is 



ded 



m 



that 



ex- 



bl 



itioned, or 

 ferior. the 



hypothefis. When limeftone or ma 

 poled 'o fuch heat as is here me 

 even to heat of a degree vaftly ii 

 carbonic gas is expelled, and the body is red 

 ced to pure lime; from the refractory natu 

 ©f which, as we leani from the fad relative 



to 



e 



