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the fea : but I have already obferved, wheti 

 treating of the ifland, and I now repeat 

 it, that I did not find one with a regular 

 form. 



At Naples, the prifmatic lavas of the 

 currents of Vefuvius, under the Park of Por- 

 ticl, have been much fpoken of. When I 

 made my cbfen^ations on this burning 

 mountain, I had not time to vifit thefe la- 

 vas. It is with great pleafure, therefore, 

 that I learn they have been examined by 

 a perfon fo well experienced in matters of 

 this nature as the Chevalier Gioeni un- 

 doubtedly is. But the celebrated prifms 

 difapppeared in the prefence of fo accurate 

 an obferver. The following is the account 

 he gives ; which is of confiderable import- 

 ance to our prefent fubjed: : — " I wifhed 

 " to examine the bafaltes which were 

 " pointed out to me as to be found on the 

 " fea-fhore, under the Royal Park of Por- 

 " tici ; but they proved to be only a com- 

 " pa(ft lava, with perpendicular and ex- 

 ** tremely irregular fiffares, forming qua- 



" drangular. 



