the wood proves the presence of uncombined oxygen. The red oxide in
this case is reduced to the protoxide. Heated upon platinum foil, it
first turns black, is reduced to the protoxide, and melts into a dark
yellow liquid. In the reduction flame, upon charcoal, it is reduced to
the metal with intumescence. After a continued blast, a yellow
sublimate of protoxide is produced upon the charcoal, and at a little
distance off, around this sublimate, a white one of carbonate of lead
is produced. This sublimate disappears when touched by the flame of
reduction, while it communicates an azure blue-tinge to the external
flame. This is likewise the case with the peroxide of lead.

The different oxides of lead produce with the blowpipe reagents the
same reactions.

_Borax_ dissolves lead compounds with the greatest readiness upon
platinum wire in the oxidation flame to a transparent bead, which is
yellow when hot, but colorless after being cooled. With the addition
of more of the lead oxide, it becomes opalescent. When heated by the
intermittent flame, and with still more of the oxide, it acquires a
yellow enamel after cooling. Heated upon charcoal, in the flame of
reduction, the bead spreads and becomes opaque. After a continued
blast, all the oxide is reduced with effervescence to metallic lead,
which melts and runs towards the edges of the bead, while the bead
again becomes transparent.

_Microcosmic Salt_ dissolves oxides of lead upon platinum wire in the
flame of oxidation easily to a clear, colorless bead, which appears,
when highly saturated, yellow while hot. A saturated bead becomes
enamel-like after cooling. The bead appears in the flame of reduction,
and upon charcoal, of a greyish color and dull. By the addition of
more oxide, a yellow sublimate of protoxide is produced upon the
charcoal. By the addition of tin, the bead appears of a darker grey,
but it is never quite opaque.

_Carbonate of Soda_ dissolves oxide of lead in the flame of oxidation
upon platinum wire quite readily to a transparent bead, which becomes
yellow when cooling, and is opaque. Upon charcoal in the flame of
reduction, it is rapidly reduced to metallic lead, which yields,
after a continued blast, a yellow sublimate of oxide upon the
charcoal.

(_b._) _Bismuth_ (Bi).--This metal occurs mostly in the metallic
state, and less frequently as the sulphide. In the pure metallic
state, it is of a reddish-white color and great lustre. It
crystallizes