Chemist and physicist, born in London, UK. He studied at London, then superintended the meteorological department of the Radcliffe Observatory, Oxford, and from 1855 lectured on chemistry at Chester. In 1859 he founded the Chemical News, and edited it until 1906. He was an authority on sanitation, discovered the metal thallium (1861), improved vacuum tubes and promoted electric lighting, and invented the radiometer (18736). He was knighted in 1897.
| Sir William Crookes | |
|---|---|
| English chemist and physicist | |
| Born |
17 June 1832 London, England |
| Died |
4 April 1919 London, England |
Sir William Crookes, OM, FRS (17 June 1832 – 4 April 1919) was an English chemist and physicist.
In 1861, Crookes discovered a previously unknown element with a bright green emission line in its spectrum and named the element thallium, from the Greek thallos, a green shoot. Crookes also identified the first known sample of helium, in 1895. He also developed the Crookes tubes, investigating canal rays.
In his investigations of the conduction of electricity in low pressure gases, he discovered that as the pressure was lowered, that the negative electrode 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).
Life
Early days
William Crookes was born in London, he was the eldest son of Joseph Crookes, a tailor of north-country origin.
Rise as prominent chemist
From 1850 to 1854 he filled the position of assistant in the college, and soon embarked upon original work, not indeed in the region of organic chemistry whither the inspiration of his distinguished teacher might have been expected to lead him, but on certain new compounds of the element selenium.
Leaving the Royal College, he became Superintendent of the meteorological department at the Radcliffe Observatory in Oxford in 1854, and in 1855 was appointed lecturer in chemistry at the Chester training college.
From this time his life was passed in London, and devoted mainly to independent work.
After 1880, he lived at 7 Kensington Park Gardens, where in his private laboratory all his later work was carried out. Crookes's life was one of unbroken scientific activity.
He was knighted in 1897, and in 1910 received the order of merit.
William died in London on 4 April 1919, two years after his wife, to whom he had been much devoted.
Legacy
The work of Crookes extended over the regions of both chemistry and physics.
Chemistry
He was always more effective in experiment than in interpretation.
The method of spectral analysis, introduced by Bunsen and Kirchhoff, was received by Crookes with great enthusiasm.
His attention had been attracted to the first problem in using a vacuum balance in the course of the thallium researches. He soon discovered the phenomenon upon which depends the action of the well-known little instrument, the Crookes radiometer, in which a system of vanes, each blackened on one side and polished on the other, is set in rotation when exposed to radiant energy.
Crookes published numerous papers on spectroscopy, a subject which always had a great fascination for him, and he made researches on a large variety of minor subjects.
Physics
He investigated the properties of the rays, showing that they travel in straight lines, cause phosphorescence in objects upon which they impinge, and by their impact produce great heat. Nevertheless, Crookes's experimental work in this field was the foundation of discoveries which have changed the whole conception of chemistry and physics.
William turned his attention to the newly discovered phenomena of radio-activity, Crookes, in 1900, achieved the separation from uranium of its active transformation product, uranium-X.
Spiritualism
In 1870 Crookes decided that science had a duty to study the preternatural phenomena associated with Spiritualism (Crookes 1870). Judging from family letters, Crookes had developed a favorable view of Spiritualism already by 1869 (Doyle 1926: volume 1, 232–233). Among the phenomena he witnessed were movement of bodies at a distance, rappings, changes in the weights of bodies, levitation, appearance of luminous objects, appearance of phantom figures, appearance of writing without human agency, and circumstances which "point to the agency of an outside intelligence" (Crookes 1874).
Crookes' report on this research, in 1874, concluded that these phenomena could not be explained as conjuring, and that further research would indeed be useful. Crookes was not alone in his views. Crookes then became much more cautious and didn't discuss his views publicly until 1898, when he felt his position was secure. From that time until his death in 1917, letters and interviews show that Crookes was a believer in Spiritualism (Doyle 1926: volume 1, 169–170, 249–251). There is a portrait of Crookes by E.
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