Crookes, Sir William


Crookes, Sir William

▪ British chemist

born June 17, 1832, London, Eng.
died April 4, 1919, London
 British chemist and physicist noted for his discovery of the element thallium and for his cathode-ray studies, fundamental in the development of atomic physics.

      After studying at the Royal College of Chemistry, London, Crookes became superintendent of the meteorological department at Radcliffe Observatory, Oxford, in 1854, and the following year gained a post at the College of Science in Chester, Cheshire. Having inherited a large fortune from his father, he devoted himself from 1856 entirely to scientific work of various kinds at his private laboratory in London. His researches on electrical discharges through a rarefied gas led him to observe the dark space around the cathode, now called the Crookes dark space. He demonstrated that cathode rays travel in straight lines and produce phosphorescence and heat when they strike certain materials. He invented many devices to study the behaviour of cathode rays, but his theory of radiant matter, or a fourth state of matter, proved incorrect in many respects.

      With the introduction of spectrum analysis by R.W. Bunsen and G.R. Kirchhoff, Crookes applied the new technique to the study of selenium compounds. In 1861 he discovered thallium in some seleniferous deposits. He continued work on that new element, isolated it, studied its properties, and in 1873 determined its atomic weight.

      During his studies of thallium, Crookes discovered the principle of the Crookes radiometer, a device that converts light radiation into rotary motion. The principle of this radiometer has found numerous applications in the development of sensitive measuring instruments. Crookes was knighted in 1897.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Crookes,Sir William — Crookes (kro͝oks), Sir William. 1832 1919. British chemist and physicist who discovered thallium (1861), invented the radiometer (1875), and studied cathode rays. * * * …   Universalium

  • Crookes , Sir William — (1832–1919) British chemist and physicist Crookes studied at the Royal College of Chemistry in his native city of London, under August von Hofmann (1848). After working at the Radcliffe Observatory, Oxford, and the Chester College of Science, he… …   Scientists

  • Sir William Crookes — William Crookes William Crookes Sir William Crookes (17 juin 1832 4 avril 1919) est un chimiste et un physicien britannique qui a donné son nom à la technique des tubes dits de Crooks grâce auxquels ont été découverts par exemple les rayons X. Il …   Wikipédia en Français

  • Sir William Crookes — noun English chemist and physicist; discovered thallium; invented the radiometer and studied cathode rays (1832 1919) • Syn: ↑Crookes, ↑William Crookes • Instance Hypernyms: ↑chemist, ↑physicist …   Useful english dictionary

  • Sir William Crookes — cathode ray tube …   Inventors, Inventions

  • Ramsay , Sir William — (1852–1916) British chemist Ramsay came from a scientific background in Glasgow, his father being an engineer and one of his uncles a professor of geology. He studied at Glasgow University (1866–69) and returned there as an assistant in 1872… …   Scientists

  • William Crookes — Sir William Crookes Nacimiento 17 de junio de 1832 Londres, Reino Unido Fallecimiento 4 de …   Wikipedia Español

  • William Crookes — Sir William Crookes (* 17. Juni 1832 in London; † 4. April 1919 ebenda) war ein britischer Physiker, Chemiker, Wissenschaftsjournalist und Parapsychologe. Crookes hat die Kathodenstrahlen sichtbar gemacht, die Grundla …   Deutsch Wikipedia

  • Crookes — William Crookes Sir William Crookes (* 17. Juni 1832 in London; † 4. April 1919 ebenda) war ein englischer Physiker, Chemiker, Wissenschaftsjournalist und Parapsychologe …   Deutsch Wikipedia

  • Crookes — William Crookes William Crookes Sir William Crookes (17 juin 1832 4 avril 1919) est un chimiste et un physicien britannique qui a donné son nom à la technique des tubes dits de Crooks grâce auxquels ont été découverts par exemple les rayons X. Il …   Wikipédia en Français