ITALY. LETTE'R xvi. 231 



haps, the fame effects by the different caufes of 

 fire and water. I fiiall be prefently more parti- 

 cular on this fubject. The varieties of antique 

 bafaltes, which I faw at Rome, are as follow.s. 



1. Bafaties Orientalis Niger is black or dark 

 grey, of a fine grain, mixed with fmall white 

 fcales, which feem to be fherl j and with fome 

 little white veins or fiiTures, filled by a fubfhnce 

 which is either quartz or a fpecies of fherl. I 

 have more than once noticed the near relation of 

 Iherl and flints. This fpecies of Oriental bafaltes 

 is moft common, extremely hard, and entirely fimi- 

 lar to Albano-lava or felce. It is likewife the 

 moft homogene and fimple in its mixture without 

 flierl-cryftallizations. 



2. Bafaltes Orientalis Niger ^ cryftallis minutis 

 immixtis, black-grey, of the fame grain, but 

 fprinkledr with plenty of white garnet-like cryjftal- 

 lizations and black glofly fherl-lamelles. Some 

 ftatues of that kind in the villa Albani. 



3. Bafaltes Orientalis Niger * commonly called 

 Fiorito, black and white marbled in irregular 

 waves. The white fpots are entirely undetermined. 



4. Bafaltes Orientalis cum partibus conftitutivis 

 Graniti ^qualiliter mixtus ; black, and of the fame 

 grain as the precedent fpecies ; but fprinkled with 

 feparated particles of quartz, red feld-fpath and 

 mica,, which feeji to have been mixed in an 



Q..4 aqueous 



