Categories: Biographical notes
Sir William Crookes (1832 – 1919) was a British chemist and physicist. He developed vacuum tubes, inventing the Crookes tube which was named affer him (and still used in school physics today). He undertook pioneering research in spectroscopy – and through this discovered a new element: thallium. He also invented the Crookes' radiometer which is an object often bought today as curiosity (it is like a tiny windmill inside a glass vessel that rotates when placed in strong sunlight). He was also a spiritualist.
