green color under a
good flame, and on cooling becomes of an opaque brick-red, the
moment it solidifies. A glass containing but a small proportion
of the oxide becomes equally red and opaque on cooling, if
treated with tin upon charcoal.

* * * * *

15. Oxide of Mercury, HgO.

Behavior with Borax on Platinum wire

in the oxidizing flame.

No reaction.

in the reducing flame.

No reaction.

Behavior with Mic. Salt on Platinum wire

in the oxidizing flame.

No reaction.

in the reducing flame.

No reaction.

* * * * *

16. Oxide of Silver, AgO.

Behavior with Borax on Platinum wire

in the oxidizing flame.

The oxide is partly dissolved and partly reduced. In small
quantity, it colors the glass yellow while warm, the color
disappearing on cooling. In larger quantity, the glass is yellow
while warm, but during cooling becomes paler to a certain point,
and then again deeper. If reheated slightly, the glass becomes
opalescent.

in the reducing flame.

On charcoal the argentiferous glass becomes at first grey from
the reduced metal, but afterwards, when the silver is collected
into a bead, it becomes clear and colorless.

Behavior with Mic. Salt on Platinum wire

in the oxidizing flame.

Both the oxide and the metal afford a yellowish glass, which,
when containing much oxide becomes opaline, exhibiting a yellow
color by daylight and a red one by artificial light.

in the reducing flame.

As in borax.

* * * * *

17. Oxide of Platinum, PtO^{2}.
18. Oxide of Palladium, PdO^{2}.
19. Oxide of Rhodium, R^{2}O^{3}.
20. Oxide of Iridium, Ir^{2}O^{3}.
21. Oxide of Ruthenium, Ru^{2}O^{9}.
22. Oxide of Osmium OsO^{2}.

Behavior with Borax on Platinum wire

in the oxidizing flame.

Are reduced without being dissolved. The reduced metal, being
infusible, cannot however be collected into a bead.

in the reducing flame.

As in the oxidizing flame.

Behavior with Mic. Salt on Platinum wire

in the oxidizing flame.

As in borax.

in the reducing flame.

As in borax.

* * * * *

23. Oxide of Gold, Au^{2}O^{3}.

Behavior with Borax on Platinum wi