takes fire, and burns with a deep yellow color, giving off brown
fumes, which coat the charcoal, to within a small distance of the
assay, with oxide of cadmium. This coating exhibits its characteristic
reddish-brown color most clearly when cold. Where the coating is very
thin, it passes to an orange color. As oxide of cadmium is easily
reduced, and the metal very volatile, the coating of oxide may be
driven from place to place by the application of either flame, to
neither of which does it impart any color. Around the deposit of
oxide, the charcoal has occasionally a variegated tarnish.

ZINC.--This metal fuses with ease, and takes fire in the flame of
oxidation, burning with a brilliant greenish-white light, and forming
thick white fumes of oxide of zinc, which coat the charcoal round the
assay. This coating is yellow while hot, but when perfectly cooled,
becomes white. If heated with the flame of oxidation, it shines
brilliantly, but is not volatilized, since the heated charcoal is,
under these circumstances, insufficient to effect its reduction. Even
under the reducing flame, it disappears very slowly.

TIN.--This metal fuses readily, and, in the flame of oxidation,
becomes covered with oxide, which, by a strong blast, may be easily
blown off. In the reducing flame, the fused metal assumes a white
surface, and the charcoal becomes covered with oxide. This oxide is of
a pale yellow color while hot, and is quite brilliant when the flame
of oxidation is directed upon it. After cooling, it becomes white. It
is found immediately around the assay, and cannot be volatilized by
the application of either flame.

MOLYBDENUM.--This metal, in powder, is infusible before the blowpipe.
If heated in the outer flame, it becomes gradually oxidized, and