----------------
Violet or Amethyst.
--+--------------------------------------+--------------------------------
| Niobic Acid in large proportion | Niobic Acid in large proportion.
| | Titanic Acid.
--+--------------------------------------+--------------------------------
Blue.
--+--------------------------------------+--------------------------------
| Oxide of Cobalt | Oxide of Cobalt.
| Tungstic Acid | Tungstic Acid.
| Niobic Acid in very large proportion.| Niobic Acid in very large
| | proportion.
--+--------------------------------------+--------------------------------
Green.
--+--------------------------------------+--------------------------------
| Oxide of Uranium | Oxide of Uranium.
| Molybdic Acid | Molybdic Acid.
| | Vanadic "
| | Oxide of Chromium.
--+--------------------------------------+--------------------------------
Opaque-grey. (The opacity generally becomes distinct during cooling.)
--+--------------------------------------+--------------------------------
| Oxide of Silver | Oxide of Silver.
| " " Zinc | " " Zinc.
| " " Cadmium | " " Cadmium.
| " " Lead | " " Lead.
| " " Bismuth | " " Bismuth.
| " " Antimony | " " Antimony.
| " " Nickel | " " Nickel.
| Telluric Acid | Telluric Acid.
--+--------------------------------------+--------------------------------
Opaque-red and reddish brown.
--+--------------------------------------+--------------------------------
| Oxide of Copper | Oxide of Copper.
--+--------------------------------------+--------------------------------

* * * * *

TABLE II.

Metallic Oxides

1. Oxide of Cerium, C^{2}O^{3}.

Behavior with Borax on Platinum wire

in the oxidizing flame.

Dissolves into a red or dark yellow glass (similar to that
produced by iron). During cooling, the color diminishes in the
intensity and becomes finally yellow. If much oxide be dissolved,
an opaque