LIGHT FROM OYSTER SHELLS.
Reading edition
It has long been known that certain compounds of lime and sulphur had the property of absorbing light, and giving it out again when placed in the dark. A simple way to do this is to expose clean oyster shells to a red heat for half an hour. When cold, the best pieces are picked out and packed with alternate layers of sulphur in a crucible, and exposed to a red heat for an hour. When cold, the mass is broken up, and the whitest pieces are placed in a clean glass bottle. On exposing the bottle to bright sunshine during the day, it is found that at night its contents will give out a pale light in the dark. Such a bottle, filled more than a hundred years ago, still gives out light when exposed to the sun, proving the persistency of the property of reproducing light. The chemicals, ground to a flour, may now be mixed with oils or water for paints, may be powdered on hot glass, and glass covered with a film of clear glass, or mixed with celluloid, papier-maché, or other plastic materials. As a paint it may be applied to a diver's dress, to cards, clock dials, sign-boards, and other surfaces exposed to sunlight during the day; the paint gives out a pale violet light at night sufficient to enable the objects to be readily seen in the dark. If the object covered with the prepared paint is not exposed to the sun, or if the light fades in the dark, a short piece of magnesium wire burned before it serves to restore the light-giving property. The preparation, under various fanciful names, is being manufactured on a large scale.
LITTLE TOMMY'S THANKSGIVING NIGHTMARE AFTER A BUSY DAY PULLING "WISH-BONES." Retributive Chorus. "Now, then, all together!"
