Chemist had hand in discovery of X-rays, but couldn't see through trickery
JOE SCHWARCZ
Freelance, July 31, 2005
The first-ever Nobel Prize in Physics was awarded in 1901 to Wilhelm Roentgen for his discovery of X-rays. One could argue that the prize really should have been shared with Sir William Crookes, the brilliant English chemist.
Ah - but that would have presented a conundrum. While Crookes excelled in many facets of science, he exhibited incredible gullibility when it came to dealing with supposed psychic phenomena.
William Crookes graduated from the Royal College of Chemistry, and thanks to a fortune he inherited from his father, set up a private laboratory in Kensington Park Gardens.
His interests were broad. Sir William was the first person to identify the element thallium, which he isolated from the waste products of industrial sulphuric acid. But Crookes' fame rests on his interest in the behaviour of gases at very low pressure.
The newly discovered phenomenon of electricity captured scientists' imagination in the 1800s. They passed current through animals, through solutions, through solids, and in some cases, through people. Crookes wondered if electricity could pass through a vacuum. So he built an evacuated glass tube and found that not only was electricity able to pass through, but an eerie glow was produced when certain substances such as barium sulphide were placed in the tube. Today we understand that a beam of electrons travels from the negative to the positive terminal in the tube, and that the light production, or fluorescence, is caused by certain molecules being excited by electrons. Fluorescent light tubes and television picture tubes are two common applications of the "Crookes tube."
It is little wonder that other scientists, such as Wilhelm Roentgen, became fascinated by Crookes' invention. One day in 1895, Roentgen was working with such a "cathode ray tube" in the dark when he happened to notice that a piece of a fluorescent barium-based mineral on a table across the room glowed whenever the tube was turned on.
To his surprise, placing a book in front of the barium platinocyanide did not block the effect. The mysterious rays, "X-rays" he called them, were going right through the book!
It did not take long for Roentgen to discover that certain substances, such as bones, did block the X-rays. Within days of his discovery he coated a plate with fluorescent material and produced an X-ray of his wife's hand. Word quickly spread and soon X-rays were being taken around the world. Doctors could now determine the location of bullets inside the body without subjecting patients to painful and often useless probings. But not everyone was happy with the new invention. Ladies feared that unscrupulous gentlemen might find a way to use X-rays to see through clothes.
Several companies responded by marketing lead lined underwear. With better understanding of X-rays these irrational fears disappeared. They were replaced by the much more realistic concerns about radiation exposure.
By the time that Roentgen received the Nobel Prize for his discovery, Crookes had gone on to other matters. He, like many of his contemporaries, became interested in spiritualism. This was an era when "mediums" entertained the public with a variety of spirit manifestations. In one of the more popular routines, the medium was securely bound to a chair inside a curtained cabinet with a tambourine or other instrument placed out of reach. Nevertheless, audiences were soon startled to hear the sound of music, apparently played by spirits who had been summoned from the other side. Gasps were heard when the curtain was opened and the medium was seen to be still tightly bound.
Crookes attended such a performance by Annie Eva Fay, an American "psychic," and was taken by it. Taken in actually, because there are a number of ways, all well-known to magicians, by which such effects can be produced.
Crookes, though, could not imagine such manifestations without the help of spirits. Still, being a man of science, he had to consider trickery. He asked Fay if she would consider being tested under "controlled" conditions. Although the medium never claimed to be anything other than an entertainer, she agreed, probably sensing some publicity that could be appropriately milked.
In 1875, Crookes used his scientific know-how to design an electrical test. After Fay was bound, she was asked to grasp an electrode in each hand. These in turn were connected to a circuit which was designed to produce a signal if she released her grip. The idea was that she could not possibly slip her hands out of the ties that bound her without letting go of the electrodes. To Crookes' astonishment, music was heard almost as soon as the curtain was drawn without any sign of a break in the circuit. He was so convinced of the infallibility of his electrical wizardry that he declared Annie Eva Fay a genuine medium who was able to summon spirits from the great beyond. Actually, the only thing Annie summoned was ingenuity. Later, in a meeting with Houdini, who was also interested in debunking spiritualists, she explained how she had fooled Crookes by gripping one of the electrodes under her knee while she slipped the bonds with her hand. One of Crookes instruments eventually turned up in the London Science Museum and testing showed that the "under the knee" effect could be easily reproduced.
Crookes even became convinced that spirits could take on a bodily form and he dedicated his energies to proving that a celebrated medium, Florence Cook, really could materialize a spirit known as "Katie King."
He seems not to have been deterred by the fact that the medium and the spirit bore an uncanny resemblance to each other. Scientist colleagues could not believe that the great man could be so readily taken in and there were rumblings of affairs between Crookes and the female mediums he investigated. It was suggested that Crookes may have preferred the label "gullible" to one of "philanderer." Maybe the whole bizarre business was just a cover for a decidedly non-spiritual dalliance.
Joe Schwarcz is director of McGill University's Office for Science and Society (www.OSS.McGill.ca).
He can be heard every Sunday from 3-4 p.m. on CJAD.
