The female of this insect is very luminous, and has no wings. The light
always becomes brighter when the worm is in motion, and it can withdraw
it when it pleases. When the light is most brilliant, it emits a
sensible heat. When a glowworm is put into a phial, and this is
immersed in water, a beautiful irradiation takes place. If the insect
be crushed, and the hands and face rubbed with it, they have a luminous
appearance, like that produced by phosphorus.