Lavoisier weighed his way to modern chemistry, and tax farming cost him his life
Antoine Lavoisier named oxygen, showed that mass survives every chemical change, and helped design the metric system. He paid for it all with money from the Ferme générale, France's detested private tax company. During the Revolution that connection sent him to the guillotine, and France exonerated him only a year and a half later.
Born into a wealthy noble family in Paris on 26 August 1743, Lavoisier inherited a fortune at five when his mother died. At the Collège Mazarin the astronomer Nicolas Louis de Lacaille gave him a lifelong love of weather observation. He qualified as a lawyer but never practised, instead studying geology with Jean-Étienne Guettard and presenting his first paper to the Academy of Sciences in 1764, on gypsum. In 1766 the King awarded him a gold medal for an essay on lighting city streets.
His great shift was making chemistry quantitative. With careful weighing he showed that sediment from long-boiled water came from the glass vessel dissolving, not water turning into earth. He overturned the phlogiston theory by showing oxygen's role in burning, named oxygen in 1778, recognized hydrogen as an element in 1783, and confirmed that matter in a closed system keeps the same mass while changing form. He also drew up the first extensive list of elements, predicting silicon, and helped reform chemical names in 1787.
Marie-Anne Paulze, whom he married in 1771 when she was 13, became a chemist in her own right: she translated English research for him, including work by Joseph Priestley, drew and engraved his instruments, and hosted scientific salons. Jacques-Louis David painted the couple in 1788, but the portrait was kept out of the Salon for fear it would inflame anti-aristocratic anger. Lavoisier also spent his wealth on public projects, from clean water for Paris and ventilation for the fire-damaged Hôtel-Dieu hospital to prison reform proposals that were largely ignored.
The tax work shaped his fate. For the Ferme générale he had a customs wall built around Paris. He also devised an acid test for tobacco cut with ash, which fizzes audibly, then noticed a little moisture improved the leaf. The company's factories began adding 6.3 percent water, delivering seventeen ounces for the price of sixteen, and Lavoisier enforced tight inspections that made retailers across France resent him. In the Revolution he was accused of tax fraud and selling adulterated tobacco, and was executed on 8 May 1794 despite appeals citing his science.
Source: Antoine Lavoisier
