sh tourmaline, wolfram,
pharmacolite, scorodite, arseniate of iron, tetraphyline, hetepozite,
uranite, phosphate of iron, do. of strontia, do. of magnesia,
polyhalite, hauyne.

4. The following metals are reduced by soda: tungstate of lead,
molybdate of lead, vanadate of lead, chromate of lead, vauquelinite,
cobalt bloom, nickel ochre, phosphate of copper, sulphate of lead,
chloride of lead, and chloride of silver.

* * * * *

The following minerals fuse on the edges alone, when heated in the
blowpipe flame:

1. The following produce beads with soda: steatite, meerschaum,
felspar, albite, petalite, nepheline, anorthite, emerald, euclase,
turquois, sodalite (Vesuvius).

2. The following minerals produce beads with a small quantity of
soda, but with the addition of more produce slags: tabular spar,
diallage, hypersthene, epidote, zoisite.

3. The following minerals produce slags only with soda:
stilpnosiderite, plombgomme, serpentine, silicate of manganese (from
Piedmont), mica from granite, pimelite, pinite, blue dichroite,
sphenc, karpholite, pyrochlore, tungstate of lime, green soda
tourmaline, lazulite, heavy spar, gypsum.

* * * * *

The reactions of substances, when fused with soda in the flame of
oxidation may be of use to the student. A few of them are therefore
given. Silica gives a clear glass.

The oxide of tellurium and telluric acid gives a clear bead when it is
hot, but white after it is cooled.

Titanic acid gives a yellow bead when hot.

The oxide of chromium gives also a clear yellow glass when hot, but is
opaque when cold.

Molybdic acid gives a clear bead when hot, but is turbid and white
after cooling.

The oxides and acids of antimony give a clear and colorless bead while
hot, and white after cooling.

Vanadic acid is absorbed by the charcoal, although it is not reduced.

Tungstic acid gives a dark yellow clear bead while hot, but is opaque
and yellow when cold.

The oxides of manganese give to the soda bead a fine characteristic
green color. This is the case with a very small quantity. This
reaction is best exhibited on platinum foil.

Oxide of cobalt gives to the bead while hot a red color, which, upon
being cooled, becomes grey.

The oxide of copper gives a clear green bead while hot.

The oxide of lead gives a clear colorless bead while hot, which
becomes, upon cooling, of a dirty yellow color and opaque.