Deathbed of Louis XIV. References for other Cases of Crystal Visions.

From dreams, in sleep or swoon, of a character difficult to believe in
we pass by way of "hallucinations" to ghosts. Everybody is ready to
admit that dreams do really occur, because almost everybody has
dreamed. But everybody is not so ready to admit that sane and
sensible men and women can have hallucinations, just because everybody
has not been hallucinated.

On this point Mr. Francis Galton, in his Inquiries into Human Faculty
(1833), is very instructive. Mr. Galton drew up a short catechism,
asking people how clearly or how dimly they saw things "in their
mind's eye".

"Think of your breakfast-table," he said; "is your mental picture of
it as clearly illuminated and as complete as your actual view of the
scene?" Mr. Galton began by questioning friends in the scientific
world, F.R.S.'s and other savants. "The earliest results of my
inquiry amazed me. . . . The great majority of the men of science to
whom I first applied, protested that _mental imagery was unknown to
them_, and they looked on me as fanciful and fantastic in supposing
that the words 'mental imagery' really expressed what I believed
everybody supposed them to mean." One gentleman wrote: "It is only
by a figure of speech that I can describe my recollection of a scene
as a 'mental image' which I can 'see' with 'my mind's eye'. I do not
see it," so he seems to have supposed that nobody else did.

When he made inquiries in general society, Mr. Galton found plenty of
people who "saw" mental imagery with every degree of brilliance or
dimness, from "quite comparable to the real object" to "I recollect