ISO 
Lead 
133 of muriat of lead, and consequently 100 parts of dry 
muriat of lead indicate 75.2, nearly , of metallic lead, and 
(if oxygenated in the same degree as in the sulphat) 4.89 
of oxygen, or 80.09 of oxyd of lead. 
The muriat of lead may also be reduced by dissolving 
it in water and immersing a rod of iron, whereby the lead 
will be precipitated in the metallic state in fine lamellae. 
Some of the analyses of the individual lead ores may 
now be mentioned. 
Vauquelin analyzed a galena from Cologne in the fol- 
lowing way. 
A quantity was roasted slowly and lost 12 per cent, of 
sulphur in the process. Another quantity was heated with 
very dilute nitric acid, which gave a smell of sulphurret 
ted hydrogen, and dissolved all the metallic part. The 
undissolved residue heated to redness, parted with its sul- 
phur, and 16.67 per cent, of silex was left. The nitric 
solution was then decomposed by sulphat of soda, and 
the sulphat of lead collected and weighed. The propor- 
tion of metal it contained (estimating iOO of the sulphat 
to be equivalent to 75.72 of metal) was 63.1 per cent. 
The liquor was then saturated with ammonia, which de- 
posited 3.3 of oxyd of iron, and lastly carbonat of potash 
threw down 5 of carbonat of lime. 
In the dry way the galena after roasting may be mixed 
with thrice its weight of black flux , * covered with salt, 
and melted, when a button of reduced lead will be found 
# Black flux is made by deflagrating together in a red hot cru- 
cible equal weights of crude argol or tartar, and nitre. In a com- 
mon way, roast an ounce of the powdered ore for two hours fre- 
quently stirring it s then add to it, of pounded green glass an 
equal weight, and of borax and black flux each also an equal 
weight, with 10 grains of lamp-black. If thrice the weight of 
black flux be used, the alkali will dissolve some of the lead, 
T. C. 
