PREFACE. xxi 



About the fame time, and during Mr. La 

 Condamine's abfence in Italy (1755 or 1756), 

 Mr. Guettard prefented to the Royal Aca- 

 demy at Paris *, a Memoir on the perfeft 

 refemblance between the Vefuvian volcanic 

 productions, and thofe which he had found 

 in Auvergne and on the Mont d' Or. 

 Similar difcoveries have iince been made 

 in many other parts of the world ; in which, 

 except thefe unnoticed monuments, no hifto- 

 rical records were left, as memorials of for- 

 mer volcanic conflagrations. 



Father La Torre s Hiftory of Vefuvius, 

 and fome modern defcriptions of ./Etna and 

 Vefuvius, though jufily confidered as claffi^ 

 cal performances, and written with much 

 hiftorical learning, candour, elegance, and 

 ingenuity, did not enlarge the views of phi- 

 lofophers, nor fpread any remarkable new 

 light on the fubject. They were highly de- 

 ficient in a mineralogical refpecl; nor had 

 their authors ever troubled themfelves about 

 the fcientific and intelligible denominations 

 of the volcanic productions, or their various 

 1 Mem. de 1' Academic Royale de Paris, 1756. 



b 3 fate, 



