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. The difficulty was to get hold of a suitable person known as a sensitive or “medium.” What a medium is, or how physically or mentally constituted to be different from other mortals, I am unable to say. He or she may not be a photographer, but must be present on each occasion of trial. Some may be mediums without their being aware of it. Like the chemical principle known as catalysis, they merely act by their presence. Such a one is Mr. D. of Glasgow, in whose presence psychic photographs have long been alleged to be obtained. He 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 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. All this I was told was what they very strongly wished me to do, as they desired to know the truth and that only. There were present, during one or other of the evenings when the trials were made, representatives of various schools of thought, including a clergyman of the Church of England; a practitioner of the healing art who is a fellow of two learned societies; a gentleman who graduated in the Hall of Science in the days of the late Charles Bradlaugh; two extremely hard-headed Glasgow merchants, gentlemen of commercial eminence and probity; our host, his wife, the medium, and myself. 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 pronounced form than that of the sitter.