Isaac Newton (1642–1726) was an English
physicist and mathematician, one of the most influential
scientists of all time and a key figure in the scientific
revolution. Newton made seminal contributions to optics,
gravity, mechanics and calculus.
He died of mercury poisoning as a result of his alchemical
Newton had a breakdown which included sending a wild accusatory letter to his friends, John Locke, whom he claimed had "endeavoured to embroil me with woemen." The French philosopher Voltaire said that Newton "was never sensible to any passion, was not subject to the common frailties of mankind, nor had any commerce with women—a circumstance which was assured me by the physician and surgeon who attended him in his last moments."