ey than in its absence.

* * * * *

11. Oxide of Tin, SnO^{2}.

Behavior with Borax on Platinum wire

in the oxidizing flame.

In small quantity dissolves slowly into a clear colorless glass,
which, when cold, remains clear, and cannot be rendered opaque
with an intermittent flame. If a saturated bead, which has been
allowed to cool, be reheated to incipient redness, it loses its
rounded form and exhibits imperfect crystallization.

in the reducing flame.

A glass containing but little oxide undergoes no change. If much
of the latter be present, a part may be reduced upon charcoal.

Behavior with Mic. Salt on Platinum wire

in the oxidizing flame.

In small quantity dissolves very slowly to a colorless glass,
which remains clear on cooling.

in the reducing flame.

The glass undergoes no change, either on charcoal or platinum wire.

* * * * *

12. Oxide of Bismuth, BiO^{3}.

Behavior with Borax on Platinum wire

in the oxidizing flame.

Dissolves readily to a clear glass which with a small amount of
the oxide is yellow, while warm, and becomes colorless on
cooling. With a larger addition, the glass is, in the hot state,
of a deep orange color, which changes to yellow and finally
becomes opaline in process of cooling.

in the reducing flame.

A glass becomes at first grey and turbid, then begins to
effervesce, which action continues during the reduction of the
oxide, and it finally becomes perfectly clear. If tin be added,
the glass becomes at first grey from the reduced bismuth, but,
when the metal is collected into a bead, the glass is again
clear and colorless.

Behavior with Mic. Salt on Platinum wire

in the oxidizing flame.

Dissolves in small quantity to a clear colorless glass. A larger
addition affords a glass which, while warm, is yellow, and
becomes colorless on cooling. When in sufficient proportion the
glass may be rendered opaque under an intermittent flame, and a
still larger addition of oxide renders the bead spontaneously
opaque on cooling.

in the reducing flame.

On charcoal, and especially with the addition of tin, the glass
remains colorless and clear, while warm, but becomes on cooling
of a