of baryta colors the flame green when heated at the point of the
reduction flame. But neither the sulphate, carbonate, nor, in fact,
any other salt of baryta, gives such a fine green color as the
chloride. The presence of lime does interfere with the reaction of
baryta, but still does not destroy its color.

(_g._) _Phosphoric Acid._--The phosphates give a green color to the
oxidation flame, especially when they are moistened with sulphuric
acid. This is best shown with the platinum forceps. The green of
phosphoric, or the phosphates, is much less intense than that of the
borates or boracic acid, but yet the reaction is a certain one, and is
susceptible of considerable delicacy, either with the forceps, or
still better upon platinum wire. Sulphuric acid is a great aid to the
development of the color, especially if other salts be present which
would 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