330 APPENDIX. 



For economical purposes, it is obtained at Pomorance in Tuscany, by 

 causing the volcanic vapors which arise in that vicinity to pass through 

 water, and then evaporating the impregnated fluid in leaden vessels, 



SILICATE OF CERIUM. 



In regular hexagonal prisms. Cleavage parallel to the axis of the 

 prism. Color pale, yellowish brown. Translucent. 



It is found with Emerald in Dolomite at Santa Fe de Bogota in Peru. 



SODA-NITRE. (See Vol. II, p. 186.) 



This salt is employed in the manufacture of nitric acid and salt-petre. 



STEINMANNITE. 



Primary form. Cube. Secondary form. Regular octahedron. 



Cleavage parallel to the cube imperfect and scarcely visible. Frac- 

 ture uneven. Surface of the crystals smooth. Lustre metallic. Color 

 pure lead-grey. Hardness =2-5. Sp. gr. =6-833. Compound Vari- 

 eties. Botryoidal. Massive, composition fine granular. In some 

 varieties a curved lamellar composition is visible. Composition also 

 compact, sometimes porous. 



1. When he-ated before the blow-pipe, on charcoal, it decrepitates 

 with violence. Its powder heated, emits the odor of sulphurous acid, 

 and a metallic globule remains as in the case of Galena, but which fi- 

 nally yields a distinct button of silver. It appears to consist of lead, 

 antimony, silver and sulphur. 



2. It is found at Przibram with Quartz, Blende and Iron Pyrites. 



TlTANIFEROUS CERITE. 



Color blackish brown. Lustre vitreous. Fracture conchoidal. Hard- 

 ness equal to that of Gadolinite. When heated it swells up ; it is acted 

 upon both by acids and alkalies. 



Analysis. 



By LAUGIER. 



Oxide of cerium " 36-00 



Oxide of iron 19-00 



Lime 8-00 



Alumina 6-00 



Water 11-00 



Oxide of manganese 1 80 



Silica 19-00 



Oxide of titanium . . . . . . 8-00 



It is found on the Coromandel coast. 



