negative electrons). Nevertheless, Crookes's experimental work in this field was the foundation of discoveries which eventually changed the whole of chemistry and physics. Crookes' attention had been attracted to the vacuum balance in the course of his research into thallium. 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. Crookes did not, however, provide the true explanation of this apparent "attraction and repulsion resulting from radiation". After 1880, Crookes lived at 7 Kensington Park Gardens in the fashionable area of Notting Hill. His household included a large multigenerational family and a number of servants. There all his later work was done, in what was then "the finest private laboratory in Britain". It comprised an entire floor of the house and included three interconnected laboratory rooms, for chemistry, physics, and mechanical construction, and a library. Crookes was able to purchase the house and build the laboratory because of his income from the National Guano Company and from various patents. By 1880 Crookes employed a paid full-time scientific assistant (first Charles Gimingham and after 1883 James Gardiner). He was also helped by his daughter Alice, who was "adept at fractionating rare earth elements" and "no mean interpreter of spectra". 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. From his home, Crookes could easily reach the Chemical News offices, the Royal Society, the Chemica Society, and the Athenaeum Club. On 16 January 1884, Crookes' father died. Crookes' daughter Florence died of scarlet fever in the same week. Joseph Crookes' estate was left in trust, divided between his three surviving sons, Alfred, William and Frank. Combined with his previous income, this ensured that Crookes was very well off. In 1886, Crookes was elected as a member to the American Philosophical Society. Later years On 13 August 1894, John William Strutt, 3rd Baron Rayleigh and William Ramsay announced the detection of a new gas in the atmosphere. On 31 January 1895 they made a full report to the Royal Society on the new gas, argon. In addition, William Crookes, who had been asked to