``No.

``They are only manifestations produced by movement.

``What we call light is a sensation produced upon our optic nerve
by the vibrations of ether, comprising between 400 and 756 trillions
per second, undulations that are themselves very obscure.

``What we call heat is a sensation produced by vibrations between 350
and and{sic} 600 trillions.

``The sun lights up space, as much at midnight as at midday.
Its temperature is nearly 270 degrees below zero.

``What we call sound is a sensation produced upon our auditory nerve
by silent vibrations of the air, themselves comprising between 32,000
and 36,000 a second.

. . . . . .


``Very many scientific terms represent only results, not causes.
``The soul may be in the same case.

``The observations given in this work, the sensations, the impressions,
the visions, things heard, etc., may indicate physical effects produced
without the brain.

``Yes, no doubt, but it does not seem so.