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William Crookes: Nineteenth Century British Chemist and Ghost Buster

My writing interests are general, with expertise in science, history, biographies, and how-to topics. I have written over 70 books.

A portrait of William Crookes

A portrait of William Crookes

Origins of Spiritualism

Man’s desire to communicate with those departed is a long-held desire, going back to references in the Bible. A connection between the netherworld was revived in 1848 in a farmhouse in Hydesville, New York.

As the story goes, the owner and his family had been disturbed by unexpected knocking sounds at night. The young daughters, Kate and Margaret Fox, were able to interact with the spirit and commanded the specter to rap repeatedly the number of times they held up their fingers. The spirit identified himself as a man who had been murdered in the house.

The press covered the strange happenings at the Fox farm, and interest in these “spirit manifestations” began to spread. The Fox sisters began a series of demonstrations in Rochester, which became known as the “Rochester Rappings.” Many Americans were starting to claim to be mediums able to communicate with the spirits of the dead. The Fox sisters would devote much of their later lives to acting as mediums in the United States and England.

During the 1850s, the spiritualism movement took on a life of its own and began to spread across America. Mediums were typically women who were believed to have a heightened sense of piety and sensitivity to spirit communications. Messages from the spirit world, through their mediums, were often practical in nature, encouraging people to rebel against the expanding commercialization, industrialization, and urbanization of the country.

Spiritualism appealed to all classes and races but was promoted primarily by the anxious new middle class. Séances and “table turnings," a practice where participants placed their hands on a table and waited for it to vibrate or rotate as the spirits moved, became popular in Victorian era parlors. By the 1860s, the practice of spiritualism had spread to England and France.

Shortly after the spiritualists began to become popular, critics started to appear, first from the pulpits of local churches. Church leaders told their congregations that spiritualism was akin to witchcraft, and attempts to communicate with the dead were forbidden. Both Protestant and Catholic churches released a steady flow of anti-spiritualist decrees.

Spiritualist churches began to appear in the United States, with the federal census of 1860 listing 17 spiritualist churches; by 1890, the number had swollen to 334. To formalize the church, the National Spiritualist Association was formed in 1893.

The spiritualist movement was not an anti-scientific group; they actively sought out those in the scientific community to gather evidence to support their claims. Spiritualism accepted that scientific principles explained the physical world; however, they contended there was an unseen world that offered not only evidence of life after death, but also the opportunity to expand mankind’s understanding of the physical world.

The invention of the telegraph in the 1850s and the telephone in the 1870s seemed to heighten the possibility of connection between the spirit world and the physical world, as this mysterious energy called electricity worked in both realms of communication.

Which was first, Matter or Force? If we think on this question, we shall find that we are unable to conceive of matter without force, or force without matter. When God created the elements of which the earth is composed, He created certain wondrous forces, which are set free and become evident when matter acts on matter.

— William Crookes

William Crookes, the Scientist

The eldest of the sixteen children of a successful tailor in London, William Crookes was born in 1832. From a young age he showed an aptitude for science. During his years at the Royal College of Chemistry, he became fascinated with the new science of photography and became an expert.

He next developed his skills as an editor and publisher of scientific periodicals. As well as founding the Chemical News, from 1863 to 1879 he was also the editor of the Quarterly Science Review. This journal provided Crookes and other scientific contributors the opportunity to provide popular and authoritative accounts of contemporary scientific developments. This publication was also a forum to influence public opinion on civic problems of the day—water purity, sewage disposal, and agricultural productivity.

Crookes took up the new field of spectroscopy and became an authority in the field. It was not long before his expertise was known, and instrument makers were asking him for design specifications. Following along the lines of other researchers, Crookes began to search for new elements by taking the spectrum of samples from his private collection of minerals.

In 1861, his efforts were rewarded when he detected a previously unknown green spectral line in a sample of selenium ore. He named the new element thallium in May 1862. Crookes’ discovery of thallium soon turned controversial when a French chemist also announced that he had isolated thallium. As is often the case in simultaneous discoveries, the glory of the find took on nationalistic overtones. British chemists rushed to protect Crookes’ honor by electing him to the prestigious Royal Society in 1863. At least in the eyes of the British scientific community, this gave Crookes the purview to take the lead to investigate thallium to determine its exact physical and chemical properties.

Crookes began in earnest to investigate the properties of thallium, which required the utmost accuracy in his measurements. He took great care to purify his reagents, to calibrate his weights, and to use an extremely sensitive balance that he mounted in an iron case where most of the air could be removed in order to increase the accuracy.

It was while operating the vacuum balance that Crookes noticed an unusual effect on the equilibrium of the balance—that it was slightly changed by differences in temperature between samples. He noticed that warmer bodies appeared lighter than colder ones. This effect could have been caused by the condensation of vapor on the colder sample, or by air currents surrounding the hotter body. He was confused as to the exact cause of the difference. Crookes felt he had stumbled upon some mysterious new link between heat and gravitation.

By 1870, William Crookes was near the top of his game. He was a successful scientific publisher, a member of the prestigious Royal Society, had discovered a new element, and was a respected member of Britain who was called upon by the leaders of society for his sage advice. But things were about to change.

Early spectrometer used for chemical analysis.

Early spectrometer used for chemical analysis.

Death of Philip Crookes

William Crookes was initially a sceptic of the spiritualist movement when it came to England; his attitude would take an abrupt about face upon the death of his younger brother, Philip, at sea in 1867. The younger Crookes had dreams of following his older brother into a technical profession and had been working on a ship laying a telegraph cable from Florida to Cuba.

On a visit to Havana with a group of his fellow workers, Phillip contracted yellow fever and died on the voyage back to England. Philips’s letters home during his voyage told a story of harsh treatment and excruciating hard work to the point of exhaustion. William was outraged about the death of his brother and went public with accusations against the company that ran the expedition. This landed Crookes in court as the company sued him for libel.

After much legal wrangling, Crookes got off with a small fine. This episode gives a glimpse of the hot-headed nature of William Crookes in emotional situations.

In the throes of depression over the death of his brother, Crookes sought solace in the spirit world. The year after his brother’s death, he told a close scientific friend of “some very extraordinary occurrences” he had witnessed of spirits of the departed that could not be explained by any known physical force. The death of Philip not only troubled William, but the larger Crookes family too; they sought comfort by attending seances to contact their dear departed family member.

The experience of the death of his brother appears to have pushed Crookes to take up the study of mediums and their supposed powers in a scientific manner. Crookes’ state of anxiety was enhanced by his frustration with the erratic behavior of his vacuum balance in his search for the atomic number of thallium. Just as the arms of his super sensitive balance seemed to move by some unknown force, maybe the spirit world held the key for him to come to grips with his brother’s death as well as the strange measurements he was encountering in his chemistry laboratory.

It was during this time that he would meet the attractive young medium Florence Cook. She would nearly be his undoing.

A Quest to Understand the Mystical Realm

Now on a mission to understand this new mystical realm, Crookes threw himself into the study of the occult, mediums, and psychic powers. He and his wife, Ellen, traveled to Paris and attended several séances run by notable mediums of the day. The Crookes made friends with the telegraphy engineer Cromwell Varley and his clairvoyant wife, Ada.

Varley had taken a keen interest in spiritualism since the early 1850s and suggested there was a strong link between reported spirt induced mechanical movements and electrical force. Varley was a believer in spiritualism and was convinced he could use his electrical experience to uncover the link between the physical and spiritual realms. Crookes professed to have an open mind as to the validity or absurdity of communication with the dead, but in reality his correspondence of that period reveals a man obsessed with proving the occult was real.

After his death, almost all of his spiritualist letters were carefully destroyed by his family; however, the few that escaped destruction imply that his reading of the occult literature and his human connections in that realm showed a man with a belief in the co-existence of other beings, or demons, with Homo sapiens.

A diary entry surviving from 1870 recorded that he had prayed to God to “allow us to receive spiritual communications from my brother passed over the boundary when in ship at sea more than three years ago…and when the early years have ended may we continue to spend still happier ones in spirit land, glimpses of which I am occasionally getting.”

Daniel Dunglas Home.

Daniel Dunglas Home.

The Investigation of the Medium Daniel Home

Crookes’ first serious scientific investigation of spiritualism was with the known medium Daniel Home. Home was born in Scotland in 1833 and moved with his aunt to Connecticut as a young boy. There he took up “spirit rapping,” the craze that had been made popular by the Fox sisters.

Finding American audiences growing bored with his show of spiritual powers, he moved to London in 1855. Home proved to be a master showman and a publicity hound. Up until 1862, Home roamed the courts of Europe and Russia casting his mystical spell on those who would have him. Home initiated a meeting with Crookes when he learned of the chemist’s interests in spirituality. The two men met in 1869, and both Crookes and his wife were charmed with Home’s good manners and apparent honesty.

Between 1870 and 1873, Crookes hosted 31 séances with Home. Most of the sessions were in the presence of many of Crookes’ immediate family members, some other mediums, and a few other invited guests. Most of the reports from the sessions were of levitations, raps, and the movement of tables, chairs, and small objects. At three of the séances, the face or spirit of Philip Crookes was reported. Over a decade later, Crookes would write up the events of a dozen of these séances and report them to the Society for Psychical Research.

Mr. Home gave permission for Crookes to investigate his psychic powers in a laboratory. In this case, the laboratory was Crookes’ first floor dining room. The windows had been fitted with heavy shutters to keep light and noise out for daytime séances. Since Crookes was in the middle of his dilemma over the anonymous readings he was getting on his research into the atomic weight of the newly discovered thallium, he devised an experiment with Mr. Home that involved a spring scale.

In the experiment, a thick mahogany plank was attached to a spring balance that was suspended from a laboratory tripod while the other end of the plank that rested on the dining table. Home’s fingers were placed on the end of the plank before the fulcrum and, on exerting his psychic powers, a depression of the spring balance from two pounds to as much as eight pounds was recorded by the observers. Testing the result himself, Crookes put his full weight on the spot where Home’s finger had been, and he was only able to depress the balance to around four pounds.

Crookes attributed this increase in weight not to any false movements from Home, but rather to a genuine flow of nervous energy or “psychic force” from Home’s body. To confirm what had happened, in Crookes’ mind, Mr. Home was clearly exhausted, and this indicated that the law of conservation of energy had been obeyed.

After the apparent success of his experiments, there was another one involving the playing of an accordion enclosed in a wire cage. Crookes was anxious to report to the scientific community his discovery of the new “psychic force.” Crookes wrote up his findings and submitted a paper to the Royal Society in June of 1871. The secretaries of the Royal Society were clearly embarrassed by Crookes’ work, and there was no way they would publish any “experimental” results that were obtained during a séance.

News of Crookes’ experiments quickly became public. A month after Crookes’ submittal to the Royal Society, The Spectator reported that Crookes’ latest paper had been rejected on the grounds of its “entire want of scientific precision in the evidence adduced.” After a second paper was submitted to the British Association, and rejected, Crookes published his experiments with Mr. Home in his Quarterly Journal in October 1871.

Controversy Over Crooke's Experiments

Crookes’ experiments with Mr. Home had stirred up a beehive of controversy. He now had many detractors and few supporters in the larger scientific community. A few of Crookes’ associates who were “believers," such as Varley, came to his aid by writing articles in support of his experimentation.

Crookes realized the Home affair had sullied his reputation amongst his fellow scientists and quickly set back to work on the strictly scientific pursuit of the determination of the atomic weight of thallium. This debacle did not diminish Crookes’ interest in psychic phenomena; however, he was much more careful in the future to publish such work only in the spiritualist, rather than the scientific, press.

That fall, Mr. Home married his second wife, a rich Russian women he had met in St. Petersburg, and the couple moved to Paris. Much ink has been spilt over the years to explain the ways in which Mr. Home had deceived the séance sitters and William Crookes—theories abound.

William Crookes and Katie King.

William Crookes and Katie King.

The Spirit of Florence Cook

Through dedicated effort, Crookes and his assistant were able to redeem themselves in the eyes of the Royal Society through the measurement of thallium’s atom mass and the invention of a radiation detector, known as a radiometer. With Daniel Home out of the picture, Crookes looked for another medium to work with and study. He and his wife began attending séances in the modest home of the Cook family on the east end of London.

The medium was Cook’s pretty dark-haired daughter Florence, or Florrie as she was called by her family, who had just turned sixteen in the summer of 1872. Florence had been working in a school as a tutor but was dismissed when her work as a spiritualist became public knowledge. Like many young Victorian women with few prospects, being a medium provided an income.

By the spring of 1872, Florence had conjured up a phantom she called “Katie King.” At this point, Florence was becoming a known medium in the spiritualist circles of London. Her benefactor and promoter, Charles Blackburn, contacted Crookes and asked if he could validate Ms. Cook’s credentials as a medium. Crookes willingly took on the project to investigate the manifestation of Katie King by Florence.

He invited Florence to sporadically live with the Crookes’ large family at their house on Mornington Road in northwest London. This would give Crookes the opportunity to study the young medium and work with her. The Crookes household was a bustling place, with their nine children, a tenth on the way, Crookes’ mother-in-law living with them, and hired help coming and going.

In 1874, Crookes began to test Florence. He captured several photographs of the manifestation of Katie King and was allowed to test her appearances with Florence in the same room. During the test, Cook was behind a curtain lying on a sofa with a shawl wrapped about her face. Then Katie appeared in front of the curtain where Crookes checked to be sure Cook was still lying on the sofa. Crookes reported that Cook was still on the sofa; however, he didn’t report that he lifted the shawl to verify it was Cook still on the sofa.

With Crookes’ expertise in photography, he was able to capture over 50 images of Cook and the spiritual apparition Katie. Only a few of the photos have survived as many were destroyed shortly before his death in 1919.

As with the investigation of Mr. Home, Crookes immediately fell under criticism from non-believers. Skeptics contended the similarities in the appearance of Katie and Florence were simply because they were the same person. Theories abound as to why Crookes was so lax with the scientific method in his research in the Cook-King collaboration. Some say he was seduced by the charms of the young woman and let his guard down, and apparently there was another young woman working with Florence.

Others contend he was such a strong believer in the spirit world and was very near-sighted, so that he simply reported what he wanted to see. And there is always the explanation the whole thing was real; Katie King was some supernatural apparition conjured from the netherworld by Ms. Cook!

A year after Crookes’ time with Katie and Florence, Katie announced at séance that her time on this earth was done. At her final appearance at séance, Katie made a dramatic exit. According to Crookes’ account, Katie walked over to where Florence was lying on the floor and touched her on the shoulder begging her to wake and explaining she had to leave. The two talked for a moment and Crookes was summoned to come and hold Florence in his arms as she was sobbing hysterically, and when he looked around, Katie was gone.

With the spirit of Katie King gone, there was no reason for further investigation of Florence, and it was at about this time that she informed Crookes she had been recently married and was giving up on being a medium. Florence would stay in retirement for six years and only make occasional appearances at séances as a lively singing and dancing spirt named Marie.

Crookes was overwhelmed with criticism from the scientific community, so much so that he stopped his active research into psychic forces. He would continue his distinguished work as a chemist and publisher and be knighted in 1897. He did remain an active supporter of spiritualism until his death in 1919. His belief in spiritualism did not seem to affect his positive view of Christianity, as he and Ellen were regular churchgoers throughout their lives.


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  • Daintith, John and Derek Gjertsen (editors). Oxford Dictionary of Scientists. Oxford University Press. 1999.
  • Kutler, Stanley I. (editor in Chief) Dictionary of American History. Third Edition. Charles Scribner’s Sons. 2003.
  • Patterson, Gary D. and Seth C. Rasmussen (editors). Charters in Chemistry: A Celebration of the Humanity of Chemistry. American Chemical Society. 2013.
  • West, Doug. Sir William Crookes: A Short Biography. C&D Publications. 2019.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2019 Doug West


Doug West (author) from Missouri on January 20, 2019:


Thanks for the comment. You and I like to read/write about the same topics. Crookes was a very interesting and controversial personality from the past.

Readmikenow on January 20, 2019:

Absolutely fascinating article. Reminds me of stories I read about Harry Houdini trying to contact his dead mother. I did an article once about scientific ghost researchers. They had some fascinating data that was ignored, laughed at and mocked by fellow scientists. The article did get published in a book, but I guess the fear of learning about spirits is still active today in some scientific circles. Enjoyed reading this!