Republic needs neither scientists nor chemists

Lavoisier’s tragedy was rooted in how he funded his scientific pursuits. To afford his state-of-the-art laboratory and equipment, he bought a share in the Ferme Générale (the General Farm), a private company that collected taxes on behalf of the French monarchy.

While Lavoisier used his wealth to advance human knowledge—often out of his own pocket—the tax farmers were deeply despised by the French public. They enforced high tariffs on basic goods and built a wall around Paris to collect tolls, a project Lavoisier himself helped design to prevent smuggling. When the French Revolution erupted, this association proved deadly.

All of these political and economic activities enabled him to fund his scientific research. As the French Revolution gained momentum from 1789 on, Lavoisier's world inescapably collapsed around him. In 1792 Lavoisier was forced to resign from his post on the Gunpowder Commission and to move from his house and laboratory at the Royal Arsenal. On 8 August 1793, all the learned societies, including the Academy of Sciences, were suppressed. It is difficult to assess Lavoisier's own attitude to the political turmoil. On 24 Nov. 1793, the arrest of all the former tax gatherers was ordered. Lavoisier was branded a traitor by the Convention under Maximilien Robespierre during the Reign of Terror, in 1794.

Lavoisier and the other former tax gatherers were formally brought to trial on 8 May 1794. According to a story, the appeal to spare his life so that he could continue his experiments was cut short by the judge: "The Republic needs neither scientists nor chemists; the course of justice cannot be delayed." Lavoisier was convicted with summary justice of having plundered the people and the treasury of France, of having adulterated the nation's tobacco with water, and of having supplied the enemies of France with huge sums of money from the national treasury. Lavoisier was tried, convicted, and guillotined on 8 May 1794 in Paris, at the age of 50. 27 of his former colleagues, were also guillotined on the same day.

Lavoisier's importance to science was expressed by Joseph Louis Lagrange who lamented the beheading by saying: "It took them only an instant to cut off this head, and one hundred years might not suffice to reproduce its like."

A year and a half after his death, Lavoisier was exonerated by the French government. When his private belongings were delivered to his widow, a brief note was included, reading "To the widow of Lavoisier, who was falsely convicted".