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The following metals, when they are fused with soda on charcoal, in
the flame of reduction, produce volatile oxides, and leave an
incrustation around the assay, viz. bismuth, zinc, lead, cadmium,
antimony, selenium, tellurium, and arsenic.

_Bismuth_, under the reduction flame, yields small particles of metal,
which are brittle and easily crushed. The incrustation is of a flesh
color, or orange, when hot, but gets lighter as it cools. The
sublimate may be driven about the charcoal from place to place, by
either flame, but is finally dissipated. While antimony and tellurium,
in the act of dissipation, give color to the flame, bismuth does not,
and may thus be distinguished from them.

_Zinc_ deposits an incrustation about the assay, which is yellow while
hot, but fades to white when cold. The reduction flame dissipates this
deposit, but not that of oxidation. All the zinc minerals deposit the
oxide incrustation about the assay, which, when moistened with a
solution of cobalt and heated, changes to green.

_Lead_ is very easily reduced, in small particles, and may be easily
distinguished by its flattening under the hammer, unlike bismuth. It
leaves an incrustation around the assay resembling that of bismuth, in
the color of it, and in the peculiar manner in which it lies around
the assay.

_Cadmium_ deposits a dull reddish incrustation around the assay.
Either of the flames dissipate the sublimate with the greatest
readiness.

_Antimony_ reduces with readiness. At the same time it yields
considerable vapor, and deposits an incrustation around the assay.
This deposit can be driven about on the charcoal by either of the
flames. The flame of reduction, however, produces the light blue color
of the antimony.

_Selenium_ is deposited on the charcoal as a grey metallic-looking
sublimate, but sometimes appearing purple or blue. If the reduction
flame is directed on this deposit, it is dissipated with a blue light.

_Tellurium_ is deposited on the charcoal as a white sublimate,
sometimes changing at the margin to an orange or red color. The
oxidation flame drives the deposit over the charcoal, while the
reduction-flame dissipates it with a greenish color.

_Arsenic_ is vaporized rapidly, while there is deposited around the
assay a white incrustation of arsenious acid. This deposit will extend
to some distance from the assay, and is readily volatilized, the
reducing flame produc