EMILY.
And is not the light of a glow-worm of a phosphorescent nature?
MRS. B.
It is a very remarkable instance of phosphorescence in living animals; this property, however, is not exclusively possessed by the glow-worm. The insect called the lanthorn-fly, which is peculiar to warm climates, emits light as it flies, producing in the dark a remarkably sparkling appearance. But it is more common to see animal matter in a dead state possessed of a phosphorescent quality; sea fish is often eminently so.
EMILY.
I have heard that the sea has sometimes had the appearance of being illuminated, and that the light is supposed to proceed from the spawn of fishes floating on its surface.
MRS. B.
This light is probably owing to that or some other animal matter. Sea water has been observed to become luminous from the substance of a fresh herring having been immersed in it; and certain insects, of the Medusa kind, are known to produce similar effects.
But the strongest phosphorescence is produced by chemical compositions prepared for the purpose, the most common of which consists of oyster shells and sulphur, and is known by the name of Canton’s Phosphorus.
EMILY.