157 
TAB. CCLXXVIII. 
PLUMBU™M_  oxygenizatum. 
Minium, or Red Ovide of Lead. 
Class 3. Metals. Order 1. Homogeneous. 
Gen. 15. Plumbum. Spec. 1. Oxygenizatum. 
Div. 1. Amorphous. 
EE 
Tiais new and truly curious production is unusually in- 
teresting, as being found naturally formed, and will pro- 
bably afford a lesson for the chemist, as the work of the 
great Laboratory of Nature: especially as it exposes a sub- 
ject usually formed by a sort of volcanic process, if I may 
so term it, and which yet has here every appearance of a 
Neptunian origin. Possibly the very process of thus pro- 
curing it may be of consequence enough to teach us how to 
preserve its most inimitable tint, which has hitherto been a 
great desideratum. It should seem by the nature of the spe- 
cimen that something has wrought a sort of furrow or con- 
cave passage through the Galena, and that this was a very 
powerful menstruum, penetrating it so deeply in some 
parts, and in such a manner, as to give the appearance of 
worm-holes: these holes are lined with the Oxide of Lead 
of the usual scarlet colour, in a fine-grained powder, about 
the thickness of paper, adhering to the Galzna rather 
closely, and which, when separated, shows a dull roughish 
site with a corroded appearance. Upon the surface of the 
Minium we may almost recognise a substance between 
Massicot and Litharge, about the same thickness, sepa- 
rating in irregular patches, in extremely fine particles, 
which, with a magnifying glass, seem to sparkle, and 
have something of a scaly appearance. In some parts they 
