reaction with charcoal and carbonate of soda.

* * * * *

LEAD.

* * * * *

Mineral. Galena

Formula. PbS.

Behavior

(1) in glass-bulb. Generally decrepitates and gives off a small
quantity of sulphur.

(2) in open tube. Gives off SO^{2}, and when strongly heated, a
white sublimate of [.Pb], [.S].

(3) on charcoal. Fuses and is reduced affording a bead of
metallic lead, and forming an incrustation of
PbO on the charcoal. Colors the outer flame
blue.

(4) in forceps. --

(5) in borax. The oxide formed upon charcoal gives the lead
reaction.

(6) in mic. salt. As in borax.

(7) with carb. soda. As alone on charcoal. The fused alkali gives a
sulphur reaction on silver.

(8) Special reactions. --

* * * * *

Mineral. Clausthalite

Formula. PbSe.

Behavior

(1) in glass-bulb. Decrepitates slightly.

(2) in open tube. Forms a sublimate of selenium, which is grey
when thickly deposited, and red when thin.

(3) on charcoal. Gives off fumes smelling strongly of selenium
and coloring the flame blue. In the reducing
flame fuses partially and incrusts the charcoal
with Se and PbO. After some time a black
infusible mass alone remains.

(4) in forceps. --

(5) in borax. The infusible residue obtained upon charcoal
gives an iron and sometimes copper and cobalt
reaction.

(6) in mic. salt. As in borax.

(7) with carb. soda. With carbonate of soda, oxalate of potash yields
a metallic bead, the fused alkali laid upon
silver and moistened produces a stain similar to
that produced by sulfur.

(8) Special reactions. --

* * * * *

Mineral. Jamesonite

Formula. [,Pb]^{3}[,,,Sb]^{2}.

Behavior

(1) in glass-bulb. Fuses and gives off