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Camden and other London séance rooms, England · 1873–1874; accounts published in 1874
In 1874, William Crookes described a white-robed figure moving between a darkened library and a laboratory full of sitters and cameras. The figure called herself Katie King; the young medium Florence Cook was said to remain in trance behind the curtain. Crookes’s published letters let us follow the investigation through its changing lighting, observations and photographic arrangements.
The question Crookes set himself
Crookes opened his February 1874 letter by identifying a practical question: when Katie was visible, where was Florence Cook? He thought arguments about seals, knots and personal character had obscured that issue. His proposed answer depended on observing two bodies rather than merely assuming that a bound or enclosed medium had stayed where she began.
His initial example came from a sitting at Mr Luxmore’s house. A rear drawing room served as the cabinet, separated from the front room by a curtain. Cook entered after the usual examination of the room. Katie emerged but said that the medium was unwell. Crookes, seated near the curtain, described hearing moaning from the space behind it while the figure stood outside.
He acknowledged that the face resembled Cook’s in the dim light. What persuaded him on this occasion was the sound apparently coming from another position. The letter is important precisely because it shows the evidence he had at that stage: a visual figure and a simultaneous sound, followed by a promise of more direct tests.
12 March: the laboratory and the library
The next published letter, dated 30 March, describes Crookes’s own house. His laboratory held the sitters; the adjoining library temporarily served as the cabinet. The boundary was a curtain, and the experiments involved moving between the two rooms.
On 12 March, Katie called him into the library because Cook had slipped awkwardly from the sofa. He reported passing the white-robed figure, then finding Cook in her ordinary black velvet dress. He raised her head and helped her back onto the sofa. He regarded the short interval between seeing Katie and touching Cook as significant.
An attempt to illuminate both figures together initially failed. Crookes followed Katie with a phosphorus lamp, found Cook on the sofa, but could no longer see Katie. His son, watching from another angle, reported seeing the lamp moving above Cook without a visible hand. These are separate observations in the letter, and the unsuccessful attempt is part of the record alongside the later result.
A lamp, shorthand notes and two figures
At a subsequent Hackney sitting, Crookes entered the cabinet after Katie had walked among the company. He arranged for a shorthand writer to record what he said, intending to preserve his immediate observations rather than reconstruct them from memory.
Using a small phosphorus lamp, he said he found Cook crouching on the floor in black velvet and Katie standing behind her in flowing white. He held Cook’s hand and alternated his inspection between the two figures. His description is detailed about position, clothing, breathing and the movement of the lamp.
He then listed perceived differences: height, complexion, fingers, pierced ears and marks on the skin. These were Crookes’s comparative observations, made during sittings, not measurements supplied by an independent laboratory. His letters allow readers to identify the particular tests that led him to his own firm conclusion.
Five cameras and forty-four negatives
The final report gives an unusually clear account of the photographic setup. Five cameras of different formats faced Katie’s position, including two stereoscopic instruments. Crookes prepared plates, sensitising baths and fixing baths in advance; an assistant helped him.
The library again served as the cabinet. One folding door had been removed and replaced by a curtain. The audience sat in the laboratory facing it, with the cameras behind them. Crookes reported forty-four negatives of varying quality rather than forty-four equally successful portraits.
For a comparison, he dressed Cook in Katie-like clothing and photographed her and himself in the same positions and lighting. He wrote that his own image aligned between the pictures while the figures differed in stature. It is a specific comparison he claimed to have made; it is not the same as a modern examination of the complete negative series.
He also recorded the limits of visibility. During some illuminated observations, Cook’s head was covered with a shawl to shield her from the light. He said he saw hands, feet and movement, but not her face. That detail belongs with the claim that the medium and figure were simultaneously present.
The household conditions
Crookes described Cook as a frequent visitor, sometimes staying for a week. He relied partly on her remaining among his household during the day and bringing little luggage. At the start of a sitting he prepared the library himself, locked a second door and retained its key.
Those arrangements show why he regarded his own home as useful: it let him control the room and observe the medium beyond the short public séance. His account also shows how much depended on relationships and trust. He believed confidence between himself, Cook and Katie improved the manifestations.
The final letter includes comparisons of pulse, hair and physical appearance, and affectionate scenes with his children. These passages help explain the tone of the investigation. The laboratory was also a family space, and Crookes’s writing combined experimental ambition with a strong personal attachment to the people and experiences involved.
The farewell and the published record
In the final séance narrative, Katie spoke privately to sitters and gave directions for Cook’s care. Crookes said he entered the cabinet with her, watched her wake the medium, and supported Cook as she became distressed. When he looked around, the white-robed figure was gone.
He closed by thanking Cook, her parents and Charles Blackburn, whose financial support had enabled the sittings. This gives the investigation a social history as well as a sequence of appearances: medium, family, patron, host, witnesses and journals all had roles in producing the surviving record.
The three letters were collected in Researches in the Phenomena of Spiritualism in 1874. They should be read as Crookes’s published case, with the observations attributed to him. They preserve much more than the familiar one-sentence claim that a scientist photographed a spirit.
Connections in the UKPX collection
The D. D. Home case explores another celebrated episode in Victorian physical mediumship. Leonora Piper’s English sittings instead centre on information, objects and personal recognition. Together they show the very different questions investigators brought to a séance.
The portrait used here shows Crookes later in life. It is not one of the Katie photographs or an illustration of a particular sitting. The source link leads to the original text, including the room arrangements and changes of light, so those details remain available for further research.
Timeline
3 February 1874: Crookes dates his first letter defending further investigation and describing the Luxmore sitting.
12 March 1874: the sofa incident in the laboratory/library arrangement.
30 March 1874: the second letter describes the lamp observations and comparisons.
Final sittings of 1874: photographic sessions and the farewell, described in the third report.
1874: the letters appear in Crookes’s collected Researches.
Sources & further reading
William Crookes, Researches in the Phenomena of Spiritualism (1874) — Full original work; especially the final three sections on Florence Cook, spirit forms and Katie King. Public-domain historical text.
Digitised 1874 edition — Bibliographic and original-edition route for the collected reports.
UKPX historical case file. Researched and checked 4 November 2026. A rounded Camden borough reference based on the public town-hall location represents the London investigation. It is not the séance house or an invitation to a private property.
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