A VARIETY of rays of light is exhibited by coloured flames, which are
not to be seen in white light. Thus, pure hydrogen gas will burn with a
blue flame, in which many of the rays of light are wanting. The flame
of an oil-lamp contains most of the rays which are wanting in sunlight.
Alcohol, mixed with water, when heated or burned, affords a flame with
no other rays but yellow. The following salts, if finely powdered, and
introduced into the exterior flame of a candle, or into the wick of a
spirit-lamp will communicate to flame their peculiar colours:
Muriate of Soda (common salt) Yellow.
Muriate of Potash Pale violet.
Muriate of Lime Brick red.
Muriate of Strontia Bright crimson.
Muriate of Lithia Red.
Muriate of Baryta Pale _apple_-green.
Muriate of Copper Bluish green.
Borax Green.
Or, either of the above salts may be mixed with spirit of wine, as
directed for Red Fire.