A. They expel the air from their air-bladder; in consequence of which, their size is diminished, and they sink instantly.
CHAPTER XXVII.
LIGHT.
Q. What is light?
A. Rapid undulations of a fluid called ether, striking on the optic nerve of the eye. (See p.[46].)
The heat of fire or of the sun sets the atoms of matter in motion; and these atoms, striking against the fluid ether, cause it to undulate.
Q. How fast does light travel?
A. Light travels so fast, that it would go eight times round the earth, while a person counts “one.”
Q. Does all light travel equally fast?