Cleavage parallel with M and P, but more perfectly par- 

 allel with the shorter diagonal. The lamina? resulting from 

 cleavage are flexible, like Gypsum. 



Lustre adamantine, inclining to resinous, pearly upon the 

 perfect face of cleavage. Color greenish-white, or yellow- 

 ish white, sometimes inclining to grey. Streak white. 

 Translucent. . 



Sectile. Hardness ^2-0. . .2-5. Sp. gr. = 6-8.. .7-0. 



1. Analysis. 

 By BROOKE. 



Carbonate of lead - - - 46-9 



Sulphate of lead - - - 53-1 



The effervescence while dissolving in nitric acid is scarcely perceptible. 

 2. It 19 found in columnarly aggregated crystals, at the Lead hills in 

 Scotland. 



DTSCLASITE. 



Massive ; imperfectly fibrous ; the fibres sometimes direr- 

 gent. 



Lustre vitreous. Color white. Translucent. It possesses 

 double-refraction. 



Tough. Hardness above Fluor. Sp. gr. = 2-362. 

 1. Heated to redness, it emits moisture. Before the blow-pipe, it 

 fuses only on the edges. With soda it forms a semi-transparent glass, 

 and with borax and salt of phosphorus it gives colorless glasses. It ge- 

 latinizes readily with muriatic acid. 



