139 
TAC (CORN 
PLUMBUM sulphatum. 
Class 3. Metals. Order 1. Homogeneous. 
Div. 3. Amorphous. 
EEE 
Tus curious, apparently new, decomposition of Galena 
is so remarkable in its property of burning with a blue flame, 
like Sulphur, that it seems a prodigy, and has from that 
circumstance been called inflammable Lead Ore. 
The upper figure shows some remains of the cubic forms 
of the Galena, the outside having been so affected as to 
have blunted and in some parts obliterated the angles. 
The lower specimen is more compact, and is striated with 
more or less zigzag lines, and has a few blotches of Galena 
about it. The outside is generally whitish with a granular 
texture passing to crystallization. Inwardly it is generally 
somewhat darker and often of a dense gray, with a horny ap- 
pearance and flinty fracture. It shines upon being slightly 
rubbed with the finger nail, and may be easily scraped. 
As this substance is scarcely known, of course there is 
no analysis recorded. Having examined it by the blowpipe, 
we annex a short account of the changes it underwent. A 
piece being laid on Charcoal, and the flame gently applied 
by the blowpipe, it became red-hot, the Sulphur sublimed 
from the interior and melted with a greasy aspect, and a 
trifling blue flame, leaving the substance rather lighter in 
colour when cold. On further urging the flame, white 
Sulphate of Lead appeared on the surface which bubbled 
and blistered, and on cooling showed some signs of facets 
and spicule. After a while it was reduced to a globule of 
Lead. On further examination we find it to be composed 
of Sulphate of Lead, and about 10 per cent. of Sulphur. 
