Question: Lucium was confimed to be an impure sample of yttrium by an English chemist who became the president of what?

Context articles: Thulium(III) oxide
Fructose
Victorium
Lucium
William Worrall Mayo
William Crookes
John Amyatt
Wollastonite
Hazel Alden Reason
Arthur Aikin

Thulium (III) oxide is a pale green solid compound, with the formula TmO.
 It was first isolated in 1879 from an impure sample of erbia by Per Teodor Cleve, who named it "thulia".
Fructose, or fruit sugar, is a simple ketonic monosaccharide found in many plants, where it is often bonded to glucose to form the disaccharide sucrose.
 It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion.
 Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847.
 The name "fructose" was coined in 1857 by the English chemist William Miller.
 Pure, dry fructose is a very sweet, white, odorless, crystalline solid and is the most water-soluble of all the sugars.
Victorium, originally named monium, is a mixture of gadolinium and terbium.
 In 1898, English chemist William Crookes reported his discovery of it in his inaugural address as president of the British Association for the Advancement of Science.
 He identified the new substance, based on an analysis of the unique phosphorescence and other ultraviolet-visible spectral phenomena, as a new chemical element, although this was later shown to be false.
 The name monium means "alone", because its spectral lines stood alone at the end of the ultraviolet spectrum.
 In 1899 Crookes renamed the purported element "victorium" in honor of Queen Victoria's recent diamond jubilee.
 He assigned it the symbol Vc.
 By 1905, however, French chemist Georges Urbain had proven that victorium was not a distinct element but rather an impurity of gadolinium.
Lucium was the proposed name for an alleged new element found by chemist Prosper Barrière in 1896 in the mineral monazite.
 Later, William Crookes confirmed that the new element was actually an impure sample of yttrium.
William Worrall Mayo ( ; May 31, 1819 – March 6, 1911) was a British-American medical doctor and chemist.
 He is best known for establishing the private medical practice that later evolved into the Mayo Clinic.
 He was a descendant of a famous English chemist, John Mayow.
 His sons, William James Mayo and Charles Horace Mayo, established a joint medical practice in Rochester in the U.S. state of Minnesota in the 1880s.
Sir William Crookes {'1': ", '2': ", '3': ", '4': "} ( ; 17 June 1832 – 4 April 1919) was an English chemist and physicist who attended the Royal College of Chemistry in London, and worked on spectroscopy.
 He was a pioneer of vacuum tubes, inventing the Crookes tube which was made in 1875.
 Crookes was the inventor of the Crookes radiometer, which today is made and sold as a novelty item.
 Late in life, he became interested in spiritualism, and became the president of the Society for Psychical Research.
John Amyatt FRSE was an English chemist.
 He was appointed King's Chemist on 24 October 1776 and the office was abolished on 14 November 1782.
Wollastonite is a calcium inosilicate mineral (CaSiO) that may contain small amounts of iron, magnesium, and manganese substituting for calcium.
 It is usually white.
 It forms when impure limestone or dolostone is subjected to high temperature and pressure sometimes in the presence of silica-bearing fluids as in skarns or contact metamorphic rocks.
 Associated minerals include garnets, vesuvianite, diopside, tremolite, epidote, plagioclase feldspar, pyroxene and calcite.
 It is named after the English chemist and mineralogist William Hyde Wollaston (1766–1828).
Hazel Alden Reason (April 1901 – 1976) was an English chemist who became a schoolteacher and wrote a popular book on the history of science for young people.
Arthur Aikin, FLS, FGS (19 May 177315 April 1854) was an English chemist, mineralogist and scientific writer, and was a founding member of the Chemical Society (now the Royal Society of Chemistry).
 He first became its Treasurer in 1841, and later became the Society's second President.