Modern spiritism; its science and religion - SpiritArchive.org

CHAPTER VIII
SECOND SIGHT AND APPARITIONS
THE bearing, direct and indirect, of this chapter on
the phenomena of Spiritism will be seen to justify
its contents. I will begin with my personal experience
of "second sight."
Extent of
Vibrations
We all know that the spectrum represents the
very limited range of our ordinary vision, at any
rate as regards colour, and that further ranges of
vibrations of what would equally be colour, could
we see them, extend on either side.
Sir Wm. Crookes points out that vibrations from
16 to 36,000 per second are known to us as sounds.
From 36,000 to 1,000,000,000 (a pretty large range)
they are imperceptible. Above 1,000,000,000 they
are perceived as electricity. From 2,000,000,000 to
250 billions ( !) (a still greater jump) the vibrations are
again imperceptible. From 250 billions to 1,000
billions they are again seen as light and colour, from
infra-red to ultra-violet. From 1,000 billions to
250,000 billions (!) they are imperceptible for a
third amazing gap, while from 250,000 billions to