Carl Wilhelm Scheele

Carl Wilhelm Scheele was a Swedish-German pharmaceutical chemist who produced the gas later called oxygen by heating red mercuric oxide and other compounds as early as 1771 to 1772, before Joseph Priestley's better-known 1774 experiment, and named it fire air. His account was delayed in publication: a manuscript sent to the printer in 1775 did not appear in print until 1777, two years after Priestley had already published, which is the main reason Priestley rather than Scheele is usually credited with the discovery. Scheele wrote to Lavoisier in September 1774 describing his method, but the letter went missing for more than two centuries and was not made public until 1992, too late to affect the credit already settled by publication order. Working largely alone with limited means, he also discovered or co-discovered chlorine, manganese, barium and molybdenum and tungsten compounds, and identified glycerol. He died in 1786 at forty-three, an early death sometimes attributed to the era's routine unprotected handling of toxic compounds including arsenic and mercury, though the exact cause is not established.