Passage: Newton died in his sleep in London on 20 March 1727 (OS 20 March 1726; NS 31 March 1727). His body was buried in Westminster Abbey. Voltaire may have been present at his funeral. A bachelor, he had divested much of his estate to relatives during his last years, and died intestate. His papers went to John Conduitt and Catherine Barton. After his death, Newton's hair was examined and found to contain mercury, probably resulting from his alchemical pursuits. Mercury poisoning could explain Newton's eccentricity in late life.

Question: What kind of poisoning helped explain Newton's later life?
Mercury