LEAD. 
539 
same situation. Brongniart says that galena appears 
to have been formed by nature at different aeras, 
but most abundantly towards the last moments of 
the general formation, since the mines of this metal 
are for the most part found in the secondary earths 
which frequently alternate with banks of chalk con- 
taining shells. 
This kind of lead ore is commonly crystallized in 
cubes, though it is by no means confined to this 
particular formation. The colour is a dark blueish 
gray, and the surface very bright. Most part of 
these ores contain more or less of silver, though the 
quantity is frequently so small as scarcely to be no- 
ticed. 
Lead is mineralized by other substances besides 
sulphur, from whence it takes different names : 
thus we have phosphorated lead ore, arseniated 
lead ore, and vitriolated lead ore. We have likewise 
several kinds named from their colour ; such as 
white, gray, red, and yellow lead ore : but as none 
of these contain any thing interesting in their de- 
scriptive characters (except to the scientific mine- 
ralogist) we shall pass on to the principal mines of 
this useful metal that at present exist in the differ- 
ent parts of Europe. 
England is very rich in lead, this mineral being 
found in great abundance in several parts of the 
country, particularly in Derbyshire. It is like- 
wise one of the principal metallic substances in the 
county of Cumberland, Alston-moor being famous 
for its lead-mines, which employ eleven hundred 
