Chemist and physicist Antoine-Laurent Lavoisier (1743–1794) was one of the most distinguished French scientists of the eighteenth century. He is credited with discovering the elements hydrogen and oxygen, formulating the law of the conservation of mass, and introducing the metric system.
But Lavoisier also made the fateful mistake of working for the unpopular government of King Louis XVI (1754–1793). After the French Revolution toppled the monarchy, the scientist was arrested, convicted of treason, and beheaded. A colleague, Joseph-Louis Lagrange (1736–1813), famously lamented after the execution: “It took them only an instant to cut off that head, and a hundred years may not produce another like it.”
Lavoisier was born in Paris to a wealthy family and educated at the Sorbonne. He received a law degree, but defied his father’s wishes by abandoning law to study chemistry beginning in the 1760s. He later joined a private tax collection firm that handled customs and levies on behalf of the king, and he married the thirteen-year-old daughter of one of France’s chief tax collectors.
Chemists were valuable to the French government, and Lavoisier was named commissioner of the Royal Gunpowder and Saltpeter Administration in 1775. One of his missions was to arrange, along with Benjamin Franklin (1706–1790), the shipment of saltpeter to the American rebels after France entered the American Revolution on the side of the colonists.
Meanwhile, he continued his experiments. Lavoisier identified oxygen in 1779 and hydrogen in 1783, naming both elements. He published his Elementary Treatise on Chemistry—considered the first chemistry textbook—in 1789. The book summarized his earlier findings and also introduced the law of the conservation of mass, the concept that in a chemical reaction the total mass will always remain the same.
Because of his service to the king and status as a tax collector, Lavoisier lost much influence after the Revolution in 1789 and the king’s execution in 1793. His scientific preeminence protected him until the next year, when he was tried, convicted, and guillotined all in one day, May 8, 1794, despite protests from other French chemists. He was fifty.
ADDITIONAL FACTS
- Combining the French passions for snails and beheadings, Lavoisier conducted a series of experiments in 1768 that proved that certain species of snails would regrow their heads after they were chopped off.
- Lavoisier borrowed the names oxygen and hydrogen from the Greek terms meaning “acid-former” and “water-former,” respectively. (Oxys means “acid”; hydro means “water.”)
- Less than two years after his execution, the French government overturned Lavoisier’s conviction and apologized to his widow.
