lame, the external flame appears of an intense crimson color. The
deepest red color is produced by the chloride of strontium,
particularly at the first moment of applying the heat. After the salt
is fused, the red color ceases to be visible in the flame, by which it
is distinguished from the chloride of lithium. The carbonate of
strontia swells up and produces a splendid white light, while the
external flame is colored of a fine purple-red. The color produced by
the sulphate of strontia is less intense. The presence of baryta
destroys the reaction of the strontia, the flame presenting the light
green color of the baryta.

If alcohol is poured over powdered strontia and inflamed, the flame
appears purple or deep crimson, particularly if the fluid is stirred
with a glass rod, and when the alcohol is nearly consumed.

The insoluble salts of strontia do not produce a very intense color.
Baryta does not prevent the reaction of the soluble salts of strontia,
unless it exists greatly in excess. In the presence of baryta,
strontia can be detected by the following process: mix some of the
substance under examination with some pure graphite and water, by
grinding in an agate mortar. Place the mixture upon charcoal, and
expose it for a while to the reduction flame. The substance becomes
reduced to sulphide of barium and sulphide of strontium, when it
should be dissolved in hydrochloric acid. The solution should be
evaporated to dryness, redissolved in a little water, and enough
alcohol added that a spirit of 80 per cent. is produced. Inflame the
spirit, and if strontia is present, the flame is tinged of a red
color. This color can be discerned more distinctly by moistening some
cotton with this spirit and inflaming it.

If strontia or its compounds are fused with a green bead of carbonate
of soda and sesquioxide of manganese, as described under the head of
baryta, a bead of a brown, brownish-green, or dark grey color is
produced. Carbonate of soda does not dissolve pure strontia. The
carbonate and sulphate of strontia melt with soda upon platinum foil
to a bead, which is milk-white when cold, but fused upon charcoal they
are absorbed. Strontia or its compounds produce with borax, or
microcosmic salt, the same reactions as baryta. When they are
moistened with nitrate of cobalt, and ignited in the oxidizing flame,
a black, or grey infusible mass is produced.

(_c._) _Lime, Oxide of Calcium _(CaO).--Lime does not occur free in
n