ITALY. LETTER XVII. 255 



he has propofed in a DifTertation prefented to the 

 Royal Society of London ; and, that the obfer- 

 ration of prifmatic cryftals in the old filver-flags, 

 feems to me very remarkable. Likely the fherls 

 in the lavas formed themfelves in the fame 

 manner. 



APPENDIX. 



Tran/lated from the Italian. 



At Moniieri in Tofcana, in the valley detta 

 Merfa di Montieri e Bochejano, the flate is ob- 

 ferved to be inferior to the fuperincumbent lime 

 and marl. The fame is feen in many other places ; 

 as, for example, at S. Giovanni alia vena in the 

 Pifane mountains. Between the flate and the 

 ftratified lime, or marl-Hone : (as Hkewiie in other 

 places between the fame (late and a rufty greenifh 

 vitreous Galeltro, filled with fpar-flakes, which in 

 fome places covers the flate :) is conftantly running 

 and obferved a large matrix, many fathoms broad, 

 which varies on account of its conflituent foffils- 

 and materials as the fuperincumbent materials* 



actions ; or rather, in the fecond, much improved, Edition of 

 his Natural Hiftory of the Earth, which is preparing for the 

 prefs. 



4 This 



