Sir William Crookes

Sir William Crookes

1832-1919

	He was a professor at the Royal College of Chemistry in London, England. He shared with Bunsen, Kirchhoff, and de Boisbaudran the honor of establishing the science of spectroscopic analysis. Using this method Crookes identified thallium and proved that certain solar spectral lines were identical with those of terrestrial helium, thus establishing the practicality of stellar spectral analysis. He also realized that certain atoms had identical chemical properties but different atomic weights (as early as 1886), and thus anticipated the concept of isotopes.
	Photographs of Goslar-Oker, Germany Photographs of Tilkerode-Mansfeld-East Harz, Germany Photographs of Geneva, Switzerland Photographs of London, England (Notting Hill)