grey matter of the brain.

It has long been known to those who have given attention to the question
that impressions were produced by the reflection of the ultra-violet
rays from objects not visible by the rays of the ordinary spectrum.
Clairvoyants were occasionally justified by the appearance on sensitive
photographic plates of figures seen and described by them as present
with the sitter, though invisible to physical sight. It is not possible
for an unbiassed judgment to reject _in toto_ the evidence of such
occurrences proffered by men of integrity on the strength of their own
experiments, oftentimes repeated. And now we have investigators who turn
their attention to the obtaining of images of subtle forms, inventing
methods specially designed with the view of reproducing them. Among
these, Dr Baraduc seems to have been the most successful, and he has
published a volume dealing with his investigations and containing
reproductions of the photographs he has obtained. Dr Baraduc states that
he is investigating the subtle forces by which the soul--defined as the
intelligence working between the body and the spirit--expresses itself,
by seeking to record its movements by means of a needle, its "luminous"
but invisible vibrations by impressions on sensitive plates. He shuts
out by non-conductors electricity and heat. We can pass over his
experiments in Biometry (measurement of life by movements), and glance
at those in Iconography--the impressions of invisible waves, regarded by
him as of the nature of light, in which the soul draws its own image. A
number of these photographs represent etheric and magnetic results of
physical phenomena, and these again we may pass over as not bearing on
our special subject, interesting as they are in themselves. Dr Baraduc
obtained various impressions by strongly thinking of an object, the
effect produced by the thought-form appearing on a sensitive plate; thus
he tried to project a portrait of a lady (then dead) whom he had known,