William Crookes

Sir William Crookes (; 17 June 1832 – 4 April 1919) was an English chemist and physicist who attended the Royal College of Chemistry, now part of Imperial College London, and worked on spectroscopy. He was a pioneer of vacuum tubes, inventing the Crookes tube, which was made in 1875. Observing cathode rays generated in these tubes, Crookes posited that "radiant matter" was a unique fourth state of matter, a foundational contribution to plasma physics.

He is credited with discovering the element thallium, announced in 1861, with the help of spectroscopy. He was also the first to describe the spectrum of terrestrial helium, in 1865. Crookes was the inventor of the Crookes radiometer, but did not discern the true explanation of the phenomenon he detected.

According to historian William H. Brock, Crookes's later work on ultraviolet eye protection arose from 1907 Royal Society investigations into cataracts among furnace and glass workers. Developed in partnership with Wigmore Street opticians Sir William Wingate and Frank Melson Wingate, by 1918 the resulting 'Crookes Lenses' under Melson Wingate Ltd combined scientific research with practical industrial safety as a manufactured product. Brock argues that this work laid the foundation for the modern sunglasses industry, while the lenses themselves were applied to industrial, military and aviation applications for much of the twentieth century, until modern sunglass branding gradually superseded them.

Biography

Early years

William Crookes was born in London in 1832, the eldest of eight surviving children (eight others died young) of Joseph Crookes (1792–1889), a wealthy tailor and real estate investor of north-country origin, and his second wife, Mary (née Scott; 1806–1884). Joseph Crookes's father, William (1734–1814), was also a tailor, whose grandfather, John Crookes (b. 1660), had been Mayor of Hartlepool, County Durham on three occasions.

Joseph Crookes had had five children with his first wife; two sons from that marriage, Joseph and Alfred, took over the tailoring business, leaving William free to choose his own path. In 1855 he was appointed lecturer in chemistry at the Chester Diocesan Training College.

In April 1856 Crookes married Ellen, daughter of William Humphrey of Darlington. Between 1864 and 1869, he was also involved with the Quarterly Journal of Science. At various times he edited the Journal of the Photographic Society and the Photographic News.

right|thumb|The element [[thallium, discovered by Crookes]]

thumb|right|The mineral [[crookesite, a selenide of copper, thallium and silver (), named for Crookes]]

His first important discovery was that of the element thallium, made with the help of flame spectroscopy. Crookes discovered a previously unknown element with a bright green emission line in its spectrum. He named the element thallium, from Greek , , meaning "a green shoot or twig". Crookes's findings were published on 30 March 1861.

Thallium was also independently discovered by Frenchman Claude Auguste Lamy, who had the advantage of access to large amounts of materials via his brother-in-law, Charles Frédéric Kuhlmann. Both Crookes and Lamy isolated the element in 1862.

Crookes developed the Crookes tube, investigating cathode rays. He published numerous papers on spectroscopy and conducted research on a variety of minor subjects. In his investigations of the conduction of electricity in low pressure gases, he discovered that as the pressure was lowered, the negative electrode (cathode) appeared to emit rays (the so-called "cathode rays", now known to be a stream of free electrons, and used in cathode-ray display devices). As these examples indicate, he was a pioneer in the construction and use of vacuum tubes for the study of physical phenomena. He was, as a consequence, one of the first scientists to investigate what is now called a plasma and identified it as the fourth state of matter in 1879. He also devised one of the first instruments for studying nuclear radioactivity, the spinthariscope.

File:Portrait of William Crookes as Hofmann's assistant.tiff | Portrait of William Crookes, age 18

File:Portrait of William Crookes, age 24.tiff | Portrait of William Crookes, age 24

File:Portrait of William Crookes, age 57.tiff | Portrait of William Crookes, age 57

File:Portrait of Sir William Crookes, O.M., age 79.tiff | Portrait of Sir William Crookes, O.M., age 79

File:Sir William Crookes 1902.jpg|Sir William Crookes by Sir Leslie Ward, 1902

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Crookes investigated the properties of cathode rays, showing that they travel in straight lines, cause fluorescence when they fall on some substances, and that their impact can produce great heat. He believed that he had discovered a fourth state of matter, which he called "radiant matter", but his theoretical views on the nature of "radiant matter" were to be superseded. He believed the rays to consist of streams of particles of ordinary molecular magnitude. It remained for Sir J. J. Thomson to expound on the subatomic nature of cathode rays (consisting of streams of negative electrons). Nevertheless, Crookes's experimental work in this field was the foundation of discoveries which eventually changed the whole of chemistry and physics.

Crookes's attention had been attracted to the vacuum balance in the course of his research into thallium. He soon discovered the phenomenon which drives the movement in a Crookes radiometer, in which a set of vanes, each blackened on one side and polished on the other, rotate when exposed to radiant energy. Crookes did not, however, provide the true explanation of this apparent "attraction and repulsion resulting from radiation".

thumb|right|Sir William Crookes in his laboratory

After 1880, Crookes lived at 7 Kensington Park Gardens in the fashionable area of Notting Hill. His household included a large multigenerational family and a number of servants. There all his later work was done, in what was then "the finest private laboratory in Britain". It comprised an entire floor of the house and included three interconnected laboratory rooms, for chemistry, physics, and mechanical construction, and a library. Crookes was able to purchase the house and build the laboratory because of his income from the National Guano Company and from various patents.

By 1880 Crookes employed a paid full-time scientific assistant (first Charles Gimingham and after 1883 James Gardiner). He was also helped by his daughter Alice, who was "adept at fractionating rare earth elements" and "no mean interpreter of spectra".

Later years

right|thumb|Sample illustration: Periodic table in the style of a space lemniscate by William Crookes

On 13 August 1894, John William Strutt, 3rd Baron Rayleigh and William Ramsay announced the detection of a new gas in the atmosphere. On 31 January 1895 they made a full report to the Royal Society on the new gas, argon. In addition, William Crookes, who had been asked to examine a sample, presented on the spectra of argon, reported that argon displayed two distinct spectra. A few month later Ramsay isolated helium from the mineral cleveite. Crookes confirmed the identify of the gas helium

Crookes himself suggested a design for a Periodic table in the style of a space lemniscate in 1898.

Crookes was knighted in 1897.

Crookes was named president of the British Association for the Advancement of Science in 1898. In his inaugural address, he outlined in detail a coming catastrophe: The wheat-eating peoples of the world were going to start running out of food in the 1930s. The reason, he said, was a dearth of nitrogen fertilizer available from natural sources. Crookes called on chemists to develop new ways of making fertilizer from the enormous stock of nitrogen in the atmosphere (which is roughly 80 percent nitrogen). His remarks on the coming famine achieved wide distribution in the press and were turned into a popular book. Scientists addressing the problem in the first years of the twentieth century included Kristian Birkeland, whose technology helped found Norsk Hydro, and Fritz Haber and Carl Bosch, whose Haber–Bosch process forms the foundation of today's nitrogen fertilizer industry.

In 1903, Crookes turned his attention to the newly discovered phenomenon of radioactivity, achieving the separation from uranium of its active transformation product, uranium-X (later established to be protactinium). Crookes observed the gradual decay of the separated transformation product, and the simultaneous reproduction of a fresh supply in the original uranium. At about the same time as this important discovery, he observed that when "p-particles", ejected from radio-active substances, impinge upon zinc sulfide, each impact is accompanied by a minute scintillation, an observation which forms the basis of one of the most useful methods in the detection of radioactivity.

In 1913, Crookes created an ultraviolet blocking lens made from glass containing cerium, but only lightly tinted. These inventions were the by-product of Crookes's research to find a lens glass formulation that would protect glass workers from cataracts. Crookes tested more than 300 formulations, each numbered and labelled. Crookes Glass 246 was the tint recommended for glassworkers. The best-known Crookes tints are A (withdrawn due to its uranium), A1, B, and B2, which absorb all ultraviolet below 350 nm while darkening visual light. Crookes's initial samples were made by Whitefriars, London, stained glass makers and Chance Brothers, Birmingham. A partnership with Sir William Wingate and his Son Frank Melson Wingate - under Melson Wingate Ltd improved the samples for commercial use.

Crookes was possibly influenced by the death of his younger brother Philip in 1867 at 21 from yellow fever contracted while he was on an expedition to lay a telegraph cable from Cuba to Florida.

In 1867, influenced by Cromwell Fleetwood Varley, Crookes attended a séance to try to get in touch with his brother.

Between 1871 and 1874, Crookes studied the mediums Kate Fox, Florence Cook, and Daniel Dunglas Home. After his investigation, he believed that the mediums could produce genuine paranormal phenomena and communicate with spirits. Psychologists Leonard Zusne and Warren H. Jones have described Crookes as gullible as he endorsed fraudulent mediums as genuine.

thumb|left|Crookes with Katie King

The anthropologist Edward Clodd noted that Crookes had poor eyesight, which may have explained his belief in spiritualist phenomena and quoted William Ramsay as saying that Crookes is "so shortsighted that, despite his unquestioned honesty, he cannot be trusted in what he tells you he has seen." Biographer William Hodson Brock wrote that Crookes was "evidently short-sighted, but did not wear spectacles until the 1890s. Until then he may have used a monocle or pocket magnifying glass when necessary. What limitations this imposed upon his psychic investigations we can only imagine." Cook was repeatedly exposed as a fraudulent medium but she had been "trained in the arts of the séance" which managed to trick Crookes. Some researchers such as Trevor H. Hall suspected that Crookes had an affair with Cook.

In a series of experiments in London, England at the house of Crookes in February 1875, the medium Anna Eva Fay managed to fool Crookes into believing she had genuine psychic powers. Fay later confessed to her fraud and revealed the tricks that she had used. Regarding Crookes and his experiments with mediums, the magician Harry Houdini suggested that Crookes had been deceived. The physicist Victor Stenger wrote that the experiments were poorly controlled and "his desire to believe blinded him to the chicanery of his psychic subjects."

In 1897, John Grier Hibben wrote that Crookes's idea of ether waves explaining telepathy was not a scientific hypothesis "he presents no facts to indicate its probability or to save it from being relegated to the sphere of bare conjecture."

In 1916, William Hope tricked Crookes with a fake spirit photograph of his wife. Oliver Lodge revealed there had been obvious signs of double exposure, the picture of Lady Crookes had been copied from a wedding anniversary photograph, but Crookes was a convinced spiritualist and claimed it was genuine evidence for spirit photography. In a review, biographer William Brock wrote that Stein made his "case against Crookes and Hope clearly and logically."

Crookes joined the Society for Psychical Research, becoming its president in the 1890s: he also joined the Theosophical Society and The Ghost Club,

References

External links

Crookes's (1874) A practical handbook of dyeing and calico-printing – digital facsimile from the Linda Hall Library