Dimethylmercury (9.1) was †rst synthesized in 1858 by George Buckton, who worked at the Royal College of Chemistry (now Imperial College) as assistant to A. W. von Hofmann. (CH3)2Hg was soon known to be poisonous. Two English chemists were fatally poisoned by it in 1865; in 1943, two Canadian secretaries were killed by fumes of the similar diethylmercury and, in 1971, a Czech chemist who had been making dimethylmercury died within a month. But no one knew quite how toxic this colourless, volatile liquid (b.p. 92°C) was until 1997.