A variety of rays of light are exhibited by colored 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 the 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 the flame their peculiar colors:

Or either of the above salts may be mixed with spirit of wine, as directed, for Red Fire.

Orange Colored Flame.

Burn spirit of wine on chloride of calcium, a substance obtained by evaporating muriate of lime to dryness.

Emerald Green Flame.

Burn spirit of wine on a little powdered nitrate of silver.

Instantaneous Flame.

Heat together potassium and sulphur, and they will instantly burn very vividly.

Heat a little nitre on a fire-shovel, sprinkle on it flour of sulphur, and it will instantly burn. If iron filings be thrown upon red hot nitre, they will detonate and burn.