362 INDEX. 



Pi/a, hot wells, 239. 



Pfizarelk, hot aluminous wells at the Solfatara, 164. 



fcaty, fuperincumbent on limefione, a fpecies of 

 Porus, 7. 



e^ volcano, 127. 

 Pelifclla (Falle), Lava, between calcareous firata, p. 

 Polzntra^ fpecies of Serpent! ne-ftone, with limeftone, marble, 



and fpar-veins, 93. 299, 300. 

 PorteHamtes, white flint, found in white china clay near Ka 



den in Bohemia, 313. 

 Porphyry, fuperineumbent on flate, feems to be a volcanic pro- 



.- duftion, 37. 157. 224. 225. 325. 329. 

 . mountains in Tyrol, near Newmark aad Brandfbl, 



3M- 



.1 Naturally breaks in fquare rhomboidal and paraile* 



lopiped columns, 325. 



i bladders and holes in the fubftance of a green an- 



tique Porphyry filled with flint or agate, 225. 



contains feld-fpath and flierl, v. fqffim. 



its Varieties. 



I. Red; Porfido Roflb antico, 222. 



1. With oblong angulated irregular white (pots. An- 

 tique, 223. 



2. With white or reddifh feld-fpath and vitreous (herl 

 in undetermined forms, from Newmark, in Tyrol, 



325- 



3. With black flierl flakes. Antique Porphyry, 225. 



II. Blacky 313. 261. 



inclofed by fragments in grey Granite, 228. 

 Varieties. 



i. With white tranfparept rouad {hcrls, from New- 

 ni-rk, 324. 



2. With 



