( "9 ) 



pumices that have flowed in the manner 

 of lavas. The figure of the pores in pumices 

 that have flovi^ed, is ufually more or lefs ob- 

 long ; whereas in the pumices of Felicuda 

 (I mean the celhilar) the pores are almoll 

 always orbicular. We mull: therefore con- 

 clude that they have been thrown out from 

 the mouths of volcanoes ; to which the glo- 

 bofe figure of many of them is perfectly 

 confonant. 



I fhould eRetm my account of the dif- 

 ferent produ6tions of this ifland very de- 

 fedive, were I not to mention another 

 which flill more confirms its volcanization : 

 I mean the puzzolana found here in fevera! 

 places, and which, when cai'efully exa- 

 mined, is found to be a mixture of minute 

 fragments of pumices, tufas, and lavas. The 

 inhabitants of Fehpuda make ufe of it, as 

 alfo the pumice, in building their houfes ; 

 in the following manner^ They bring car- 

 bonates of lime (calcareous earths) from 

 Sicily ; and burn them in furnaces, which 

 ai*e erected, for greater convenience, on the 

 I A fea- 



