striking phenomena in
photographing what is invisible to the eye may be produced by the agency
of fluorescence. He quotes the demonstration by Dr. Gladstone, F.R.S.,
at the Bradford Meeting of the British Association in 1873, showing that
invisible drawings on white cards have produced bold and clear
photographs when no eye could see the drawings themselves. Hence, as Mr.
Taylor says, the photographing of an invisible image is not
scientifically impossible.

Mr. Taylor then proceeds to describe some personal experiments. He says:
"For several years I have experienced a strong desire to ascertain by
personal investigation the amount of truth in the ever-recurring
allegation that figures other than those visually present in the room
appeared on a sensitive plate.... Mr. D., of Glasgow, in whose presence
psychic photographs have long been alleged to be obtained, was lately in
London on a visit, and a mutual friend got him to consent to extend his
stay in order that I might try to get a psychic photograph under test
conditions. To this he willingly agreed. My conditions were exceedingly
simple, were courteously expressed to the host, and entirely acquiesced
in. They were, that I for the nonce would assume them all to be
tricksters, and to guard against fraud, should use my own camera and
unopened packages of dry plates purchased from dealers of repute, and
that I should be excused from allowing a plate to go out of my own hand
till after development unless I felt otherwise disposed; but that as I
was to treat them as under suspicion, so must they treat me, and that
every act I performed must be in the presence of two witnesses; nay,
that I would set a watch upon my own camera in the guise of a duplicate
one of the same focus--in other words, I would use a binocular
stereoscopic camera and dictate all the conditions of operation....

"Dr. G. was the first sitter, and for a reason known to myself, I used a
monocular camera. I myself took the plate out of a packet just
previously ripped up under the surveillance of my two detectives. I
placed the slide in my pocket, and exposed it by magnesium ribbon which
I held in my own hand, keeping one eye, as it were, on the sitter, and
the other on the camera. There was no background. I myself took the
plate from the dark slide, and, under the eyes of the two detectives,
placed it in the developing dish. Between the camera and the sitter a
female figure was developed, rather in a more