uld be liable to hide the color of the phosphoric acid. In this
reaction with phosphates, the water should be expelled from them
previous to melting them with sulphuric acid. They should likewise be
pulverized. Should soda be present it will only exhibit its peculiar
color after the phosphoric acid shall have been expelled; therefore,
the green color of the phosphoric acid should be looked for
immediately upon submitting the phosphate to heat.

(_h._) _Molybdic Acid._--If this acid or the oxide of molybdenum be
exposed upon a platinum wire to the point of the reduction flame, a
bright green color is communicated to the flame of oxidation. Take a
small piece of the native sulphide of molybdenum, and expose it in the
platinum tongs to the flame referred to above, when the green color
characteristic of this metal will be exhibited.

(_i._) _Telluric Acid._--If the flame of reduction is directed upon a
small piece of the oxide of tellurium placed upon charcoal, a bright
green color is produced. Or if telluric acid be submitted to the
reduction flame upon the loop of a platinum wire, it communicates to
the outer flame the bright green of tellurium. If the sublimate found
upon the charcoal in the first experiment be submitted to the blowpipe
flame, the green color of tellurium is produced while the sublimate is
volatilized. If selenium be present the green color is changed to a
deep blue one.

D. YELLOW.

The salts of soda all give a bright yellow color when heated in the
platinum loop in the reduction flame. This color is very persistent,
and will destroy the color of almost any other substance. Every
mineral of which soda is a constituent, give this bright orange-yellow
reaction. Even the silicate of soda itself imparts to the flame of
oxidation the characteristic yellow of soda.

E. RED.

(_a._) _Strontia._--Moisten a small piece of the chloride of
strontium, put it in the platinum forceps and submit it to the flame
of reduction, when the outer flame will become colored of an intense
red. If the salt of strontia should be a soluble one, the reaction is
of a deeper color than if an insoluble salt is used, while the color
is of a deeper crimson if the salt is moistened. If the salt be a
soluble one, it should be moistened and dipped into the flame, while
if it be an insoluble salt, it should be kept dry and exposed beyond
the point of the flame. The carbonate of strontia should be moistened
with hydrochloric acid