Memoires de Physique et de Chimie

Born in Paris of a well-to-do family, Antoine Lavoisier received a good education, and, at an early age, became interested in science. He had an extraordinary ability to make accurate measurements and conduct careful experiments. Lavoisier made the measurement that Robert Boyle had neglected by weighing the tin oxide and the retort (particularly the air inside the retort), and noted that the total system did not gain or lose weight; he then concluded that during the calcination the metal received a substance from the air. Lavoisier realized that the true state of Joseph Priestley's "dephlogistonated air" consists of at least two substances---one that supports combustion, oxygen; and another, nitrogen. On May 8, 1794, Lavoisier was sent to the guillotine because he was part owner of a tax-collecting firm. According to tradition, the presiding judge responded to a plea on Lavoisier's behalf by saying, "The Republic has no need for scientists. Let justice take its course." 020