506 DOMAIN XII. VOLCANIC. 



fine paste of reddish lava, which had a tendency 

 to pass to the state of pumice. 



" 3. Bricia, similar in aspect to the preceding, 

 but different from it in as much as the fragments 

 of black lava, instead of being porous, are in the 

 state of semi- vitreous drosses, of a very bright 

 black. The grey paste which unites this bricia, 

 and gives 4t a strong consistence, is composed 

 of fine particles, but rather scaly, very nearly 

 allied to hard pumice. 



" 4. Bricia, formed of angular fragments of 

 black porous lava, of some small grains of white 

 felspar, opake, blended in a paste of grey pu- 

 mice with small pores. 



" 5. Bricia, with angular fragments of white 

 calcareous stone, grey and sometimes reddish, of 

 the nature of marble, capable of receiving a po- 

 lish, every where and in every direction enclosed 

 in a grey lava, hard, sprinkled with fragments 

 and crystals of white felspar, diaphanous and 

 shattered, of black hornblende, with some grains 

 of pyroxene of a grass green, and with some 

 spangles of silvery mica: this last is found in it 

 in a very small quantity. This bricia is hard 

 enough to be sawed and polished : it strongly 

 attracts the magnet. 



" 6. Bricia, with large fragments of white 



