[4] His interests, ranging over pure and applied science, economic and practical problems, and psychic research, made him a well-known personality and earned him a substantial income.

At the end of his second year, Crookes became a junior assistant to August Wilhelm von Hofmann, doing laboratory demonstrations and helping with research and commercial analysis.

He worked with Manuel Johnson at the Radcliffe Observatory in Oxford in 1854, where he adapted the recent innovation of wax paper photography to machines built by Francis Ronalds to continuously record meteorological parameters.

Their first child, Alice Mary (born 1857, later Mrs. Cowland) remained unmarried for forty years, living with her parents and working as an assistant to her father.

[3] Married and living in London, Crookes sought to support his new family through independent work as a photographic chemist.

[3] In 1859, he founded the Chemical News, a science magazine which he edited for many years and conducted on much less formal lines than was usual for the journals of scientific societies.

[3][10][11][12][13][14][15] 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.

[3][22][23][24] 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.

It remained for Sir J. J. Thomson to expound on the subatomic nature of cathode rays (consisting of streams of negative electrons[27]).

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.

It comprised an entire floor of the house and included three interconnected laboratory rooms, for chemistry, physics, and mechanical construction, and a library.

He was also helped by his daughter Alice, who was "adept at fractionating rare earth elements" and "no mean interpreter of spectra".

[3] His daily routine was to manage his commercial affairs in the morning, do further business or go to scientific meetings in the afternoon, eat dinner at 7, work in his library from 8 to 9, and then in the laboratory until after midnight.

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.

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.

[37] In 1903[contradictory], 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).

[38] Crookes observed the gradual decay of the separated transformation product, and the simultaneous reproduction of a fresh supply in the original uranium.

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.

Eric Deeson notes that Crookes's studies of the occult are related to his scientific work on radiometry in that both involved the detection of previously undiscovered forces.

[50] 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.

[55][56] Psychologists Leonard Zusne and Warren H. Jones have described Crookes as gullible as he endorsed fraudulent mediums as genuine.

"[58] Biographer William Hodson Brock wrote that Crookes was "evidently short-sighted, but did not wear spectacles until the 1890s.

Regarding Crookes, Lyons wrote, "Here was a man with a flawless scientific reputation, who discovered a new element, but could not detect a real live maiden who was masquerading as a ghost".

[67] 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.

"[68] 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.

[3]: 474 The physiologist Gordon Stein suspected that Crookes was too ashamed to admit he had been duped by the medium Florence Cook or that he conspired with her for sexual favors.

[70] In a review, biographer William Brock wrote that Stein made his "case against Crookes and Home clearly and logically.