produce a yellowish flame for a while, until the carbonic acid is
driven off, when the red color of the lime may be discerned.

If the borate or phosphate of lime be used, the green color of the
acids predominates over the red of the lime. Baryta also destroys the
red color of the lime, by mixing its green color with it. There is but
one silicate of lime which colors the flame red, it is the variety
termed tabular spar.


5. EXAMINATIONS IN THE BORAX BEAD.


In order to examine a substance in borax, the loop of the platinum
wire should, after being thoroughly cleaned, and heated to redness, be
quickly dipped into the powdered borax, and then quickly transferred
to the flame of oxidation, and there fused. If the bead is not large
enough to fill the loop of the wire, it must be subjected again to the
same process. By examining the bead, both when hot and cold, by
holding it up against the light, it can be soon ascertained whether it
is free from dirt by the transparency, or the want of it, of the bead.

In order to make the examination of a substance, the bead should be
melted and pressed against it, when enough will adhere to answer the
purpose. This powder should then be fused in the oxidation flame until
it mixes with, and is thoroughly dissolved by the borax bead.

The principal objects to be determined now are: the color of the borax
bead, both when heated and when cooled; also the rapidity with which
the substance dissolves in the bead, and if any gas is eliminated.