Question: Lucium was confimed to be an impure sample of yttrium by an English chemist who became the president of what?
Sentence (from "William Crookes"): 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.
Relevant evidence: Yes