MIX some common salt with spirit of wine in a platinum or metallic
cup; set the cup upon a wire frame over a spirit-lamp, which should
be inclosed on each side, or in a dark-lantern: when the cup becomes
heated, and the spirit ignited, it will burn with a strong yellow
flame; if, however, it should not be perfectly yellow, throw more salt
into the cup. The lamp being thus prepared, all other lights should
be extinguished, and the yellow lamp introduced, when an appalling
change will be exhibited; all the objects in the room will be but of
one colour, and the complexions of the several persons, whether old or
young, fair or brunette, will be metamorphosed to a ghastly, death-like
yellow; whilst the gayest dresses, as the brightest crimson, the
choicest lilac, the most vivid blue or green—all will be changed into
one monotony of yellow: each person will be inclined to laugh at his
neighbour, himself insensible of being one of the spectral company.
Their astonishment may be heightened by removing the yellow light to
one end of the room, and restoring the usual or white light at the
other; when one side of each person’s dress will resume its original
colour, while the other will remain yellow; one cheek may bear the
bloom of health, and the other, the yellow of jaundice. Or if, when the
yellow light only is burning, the white light be introduced within a
wire sieve, the company and the objects in the apartment will appear
yellow, mottled with white.
Red light may be produced by mixing with the spirit in the cup over
the lamp, salt of strontian instead of common salt; and the effect of
the white or yellow lights, if introduced through a sieve upon the red
light, will be even more striking than the white upon the yellow light.