He is of opinion with me *, that the globe was formed by 

 cryftallifation. In fpeaking of mountains, he lays, that vol- 

 canic mountains, fuch as Vefuvius, ^tna, &c. exifted ante- 

 rior to the eruption of volcanoes, and that fubterranean fires 

 were kindled up in their bowels. 



G, A. Deluc has attacked this latter part of the opinion of 

 Kirwan. He thinks that the foci of fubterranean fires are at a 

 great depth, and that volcanic mountains, fuch as Veluvius, 

 -^tna, the Lipari iflands, &c. were formed chiefly from mat- 

 ters thrown up by volcanoes and accumulated in the neio-h- 

 bourhood. 



Breiflak has given a phyfical topography of Campania. He 

 firft difcovered there, in 1793, ^^ extinguiihed volcano, which 

 fecms to have been much more confiderable than Wfuvius, 

 and to approach near to .Etna. It is called Rocca-Mojitfioa. 

 He fuppofes with Giocni, that the firft origin of V^efuvius was 

 at the bottom of the Tea. He obferved a foiirce of petroleum 

 at the bottom of the fea oppofite to Mount Vefuvius, and at 

 the diftance of fomewhat lefs than a mile from the fliore. 

 When drops of this fubliance rife to the furfire c.f the water, 

 they form on it fpots perfeol:ly rmmd, of from three to tour 

 inches in diameter, and of a yellcwilh-brown colour. A 

 fpring of petroleum near Vefuvius, might afford fome affiii- 

 ance to a framer of fyftems. By combining this phenonienoa 

 with other fprings of petroleum in the neighbourhood of the 

 Appenines, and wiih the foffil coal of Benevento and Gifoae, 

 wliich nothing preverits us from fuppofing to be extended 

 below the earth, we may figure to ourfelves under Vefuvius 

 an immenfe refervoir of bitumen, kindled by an ele£liie 

 fliock, or by fome other unknown caufe. 



The combuftion will continue as long as the mafs of the 

 rcfcr\'oir is not cotifumed, and may be renewed whenever a 

 new caufe of inflammation afts again upon a new quantity 

 of bitumen. 



France at prcfcnt is fubjeft to earthquakes, which, if we 

 are to judge by the confiderable number of extinguiflied vol- 

 canoes found there, muft formerly have been very comnaon. 



• Thisis ixtraded f*om the "jowtial ck Phj/i^ue, of wiuch DeLniCT 

 tbLfic ii etlifjjr. 



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