APPENDIX. 331 



URAN- BLOOM. 



In small crystalline flakes. Color bright yellow, be- 

 tween lemon-yellow and sulphur-yellow. Opake with lit- 

 tle lustre. 



1. When slightly heated before the blow-pipe, its color becomes or- 

 ange-yellow. It is soluble with effervescence in acid, yielding a yellow 

 solution, which affords a brown precipitate with prussiate of potash, thus 

 proving it to be a carbonate of uranium. 



2. It occurs in silver veins at Joachimsthal in Bohemia, with Pitch- 

 blende and Phannacolite. 



URANITE. 



It is found in small quantity in thin yellow scales at Middletown, 

 (Conn.) where it exists in granite associated with Columbite, Apatite 

 and Albite. 



VANADIATE OF LEAD. 



There appears to be no reason for separating this mineral from Pyro- 

 morphite. It is imperfectly crystallized in hexagonal prisms, and bo- 

 tryoidal, as well as in thin coatings. Color straw-yellow to reddish- 

 brown. Opake and dull. Before the blow-pipe, in a pair of forceps, it 

 fuses, and on cooling retains its yellow color ; if kept for some time in 

 fusion, however, it is changed into a steel-grey porous mass, which upon 

 charcoal, yield immediately globules of lead. Alone, on charcoal, it fu- 

 ses readily, exhales the odor of arsenic, is reduced, and leaves, after 

 heating in the inner flame, a steel-grey, very fusible slag, which exhib- 

 its the reactions of chromium. It forms green solutions with the sul- 

 phuric and muriatic acids, and a beautiful yellow solution with nitric 

 acid. The variety from Mexico, according to BERZELIUS, consists of 



Chloride of lead 25-33 



Vanadiate of lead 74-00 



Hydrous ox. iron 0-67. 



It occurs at Wanlockhead in Dumfriesshire, sprinkled over Calamine. 



END OF THE SECOND VOLUME. 



