A Luminous Bottle Which Will Show The Hour On A Watch In The Dark
Throw a bit of phosphorus, of the size of a pea, into a long glass
phial, and pour boiling oil carefully over it, till the phial is
one-third filled. The phial must be carefully corked, and when used
should be unstopped, to admit the external air, and closed again. The
empty space of the phial will then appear luminous, and give as much
light as an ordinary lamp. Each time that the light disappears, on
removing the stopper it will instantly re-appear. In cold weather the
bottle should be warmed in the hands before the stopper is removed. A
phial thus prepared may be used every night for six months.