William Crookes and the Spectral Visitor

"To what does love not compel us?" - Martial

Sir William Crookes had set aside part of his home on Mornington Road in London as a private laboratory. Many great events would transpire here, but the first, in 1861, was his observation of a green line in the spectra of certain selenium compounds, an observation that led Crookes to the discovery of the element thallium. However, spectral investigations of a different sort are the subject of this Tale.

The importance of Florence Cook in the field of spiritualism "can hardly be exaggerated." Indeed, it is a "cornerstone of the faith" (Hall 1984). And it was the support of Sir William Crookes that made the reputation of Florence Cook. Fournier d’Albe, Crooke's biographer, went so far as to claim that all the physical phenomena of spiritualism were ultimately based on the work of Sir William (Hall 1984).

Florence Cook had it all: youth, beauty, charm, and a thriving business. That business was conducting séances, and Cook’s much-in-demand specialty was the full-form materialization of the spirit "Katie King." Florence was set for life—as long as nothing interrupted the flow of money from her wealthy patron, Charles Blackburn.

But on the ninth of December 1873, catastrophe struck! An impertinent guest at the evening séance grabbed and struggled with the materialized Katie King. The lights were immediately extinguished and two of those present (one would later marry Florence) rescued the "spirit" and escorted her back to the "cabinet" where Florence was tied up (in theory). Accusations of fraud spread quickly and Blackburn’s continued financial support was in jeopardy (Hall 1984).

Within days of this embarrassing episode, Florence approached the renowned William Crookes, who had recently investigated another medium by the name of Daniel Home, to request that he perform an impartial scientific investigation into the phenomena occurring at her séances. Skeptics might have suspected that Florence’s request was influenced by the fact that Crookes had rendered Home a favorable verdict.

Crookes immediately agreed and commented that it was his duty to help "remove an unjust suspicion which is cast upon another" especially when this "person is a woman—young, sensitive, innocent" (Crookes 1905).

The ensuing investigations went on for over six months, often taking place in Crookes’s home. In fact, it was sometimes necessary for the sake of the investigations that Florence live with William, his wife Ellen and their children. In a typical séance, the "sitters" (i.e. guests) occupied Crookes’s laboratory while the library, separated from the lab with a curtain, served as a "cabinet" in which Florence would be tied up. Florence typically wore a black velvet dress but the spirit Katie, when she appeared before the sitters, usually dressed in white. On one occasion however, Katie surprised those present by appearing in Florence’s clothes. Katie apologized by explaining that the psychic forces hadn’t been strong enough for her to bring her own clothes from the "other side."

Sometimes there were doubters at these séances who commented on the remarkable resemblance between the medium Florence Cook and the spirit Katie King - implying that Florence and Katie were one and the same. Crookes vigorously disputed these scurrilous accusations by noting several differences between the two, e.g. height, complexion, smoothness of skin and even heart rate (Crookes 1905). But the key evidence, which Crookes dutifully reported to Florence’s patron Charles Blackburn, was that he had personally seen Katie and Florence together when he (and he alone) had been invited into the cabinet. Crookes’s opinion: "to imagine that a school-girl of fifteen should be able to conceive and then successfully carry out for three years so gigantic an imposture" does "violence to one’s reason." (Crookes 1905).

Ultimately, even the support of Sir William Crookes didn’t prove sufficient, and Blackburn’s faith in Florence eroded. By the end of 1874, Blackburn had discontinued his financial assistance. It was then that Florence broke off the relationship with Crookes.

Unpalatable as it might be, we must ask ourselves if William Crookes, a forty-something man of science and important pioneer in the nuclear science, might have been used by a teenager. And we must consider an even more distasteful question: could Crookes have traded his scientific integrity for an affair that sometimes took place under the very roof he shared with his wife and children?" Sadly, gentle reader, this is the conclusion of Trevor Hall, author of The Medium and the Scientist (Hall 1984).

Hall was not the first to suspect as much. Contemporary accounts, even those of ardent spiritualists, suggested that the relationship between Crookes and Florence had been less than impartial, e.g. one observer referred to Crookes’s "‘gush’ upon her loveliness." But Hall had access to previously unavailable papers, and many of these papers were damning evidence indeed. This evidence included independent accounts from two gentlemen who had known her (in the Biblical sense) that Florence had confessed that she and Crookes had carried on an affair and that his "investigations" had merely been a cover. Moreover, she had admitted to these gentlemen that her séances had been totally fraudulent and that Crookes knew as much!

If it is true that Crookes compromised his scientific integrity for Florence, he was ultimately left with nothing to show for it—she left him as soon as he was no longer useful. The end of the affair must have had an impact on Crookes, but what that impact was, can only be imagined. Crookes avoided discussing the subject and his correspondence with Florence was mysteriously destroyed. But to Trevor Hall (1984), "It seems possible, indeed, that the enforced sublimation of the violent passions aroused by Florence Cook may have been responsible in part for the single-minded diligence which produced Crookes’s most valuable work."

In other words, the breakup of the affair directly led to Crookes’s pioneering investigations into cathode rays, the development of gas discharge tubes of the type used by Rontgen, the discovery of uranium X (Th-234/Pa-234) that triggered Rutherford and Soddy’s theory of atomic transmutation, and the invention of the spinthariscope—the first radiation counter and the device that revealed the nature of the nuclear atom.

If Hall is correct, can there be any doubt that the atomic age owes an immense and unacknowledged debt to the persuasive charms of that teenage temptress, Florence Cook?


  • Crookes, W. Researches Into the Phenomena of Modern Spiritualism. Austin Publishing Co.; Rochester; 1905.
  • Hall, T.H. The Medium and the Scientist. Prometheus Books; Buffalo; 1984.
  • Strutt, R.J. Life of John William Strutt, Third Baron Rayleigh, O.M., F.R.S. University of Wisconsin Press; Madison; 1968.