( 3^4 ) 



of the conftltuent principles, unlefs w^ 

 choofe to fuppofe that in the Euganean felt- 

 fpars, befides the elements common to that 

 ftone, there exifts fome other which facili-^ 

 tates their fufion, though it is imperceptible 

 to the eye^ the external appearance of the 

 fufible exactly refembUng that of the infu- 

 fible feltfpars. 



With refped to the produd by fufion in 

 common fire, of the lavas of the Euganean 

 mountains, it is found to be exadly the 

 fame with that of other lavas, I mean an 

 enamel or glafs, as appears from what has 

 been faid above. The adion of our com- 

 mon fire, therefore, deftroys in thefe volca* 

 nic produds that primitive charaderiftic 

 ftrudure which had been left in them by 

 the fubterranean conflagrations. 



The bafaltes of Vulcano and Felieuda are 

 produds of fire, and equally fo are thofe of 

 Monte Roflb, Monte Ortone, and Catajo j 

 for they are integrant parts of continued 

 \olcanic rocks j which truth did not efcape 



the 



