5. Oxide of Iron, Fe^{2}O^{3}.

Behavior with Borax on Platinum wire

in the oxidizing flame.

With a small proportion of oxide, the glass is of a yellow
color, while warm, and colorless when cold; with a larger
proportion, red, while warm, and yellow, when cold; and with a
still larger amount, dark-red, while warm, and dark-yellow, when
cold.

in the reducing flame.

Treated alone on platinum wire, the glass becomes of a
bottle-green color (F^{3}O^{4}), and if touched with tin, it
becomes of a pale sea-green. On charcoal with tin, it assumes at
first a bottle-green color, which by continued blowing changes
to a sea-green (FeO).

Behavior with Mic. Salt on Platinum wire

in the oxidizing flame.

With a certain amount of oxide, the glass is of a yellowish-red
color, which on cooling changes to yellow, then green, and
finally becomes colorless. With a large addition of oxide, the
color is, when warm, dark red, and passes, while cooling, into
brownish-red, dark green, and finally brownish-red. During the