The Reign of Terror destroyed thousands of lives, but in the scientific community, Antoine Lavoisier's death was arguably the most devastating. Known for revolutionizing chemistry and conducting groundbreaking experiments during the Enlightenment, Lavoisier's aristocratic status eventually condemned him. Lavoisier and his wife, Marie-Anne, worked together as the father and mother of modern chemistry, designing and carrying out experiments. Together, they built an international reputation.
Like most 18th-century scientists, the Lavoisiers were aristocrats. But unlike aristocrats ridiculed for their extravagant tastes, the Lavoisiers spent their money on things like diamonds for scientific experiments. Antoine also revolutionized French gunpowder, helping his country win wars. But during the bloodiest days of the French Revolution, high status meant the opposite of protection.
When the guillotine took off Antoine's head, a famous mathematician declared, "It took them only an instant to cut off that head, and a hundred years may not produce another like it."
Antoine and Marie-Anne Lavoisier were a chemistry power couple in the 18th century. Antoine led the chemical revolution, established the law of conservation of mass, and named several elements, including oxygen, hydrogen, and carbon. Together, the Lavoisiers battled Joseph Priestley's research on oxygen and promoted a lab-based approach to chemistry.
The Lavoisiers were also aristocrats and Antoine, a former tax collector during the French Revolution. When the Reign of Terror turned its sights on Antoine, his groundbreaking scientific achievements couldn't protect him.
During the 1700s, most scientists believed in the phlogiston theory, which supposedly explained why things burn. Antoine Lavoisier disagreed with the concept and argued that the "dephlogisticated air" his rival Joseph Priestley had identified was oxygen. The friendly rivalry between Priestley and Lavoisier produced volumes of correspondence detailing their findings.
History credits both Priestley and Lavoisier for discovering oxygen, though Priestly believed he had found dephlogisticated air, a gas that Antoine named oxygen.
Antoine Lavoisier is most renowned for the law of conservation of mass and the elements he named. During the chemical revolution, Antoine argued that elements of set weights comprise the world. He tested that theory in 1772 by burning a diamond.
During the experiment, Antoine placed a diamond in a sealed jar and shined an enormous magnifying glass on it. The diamond burned and seemed to disappear completely, yet Antoine found the jar's weight had not changed. He used this result to demonstrate how mass conservation is a law of nature.
In later tests, Antoine determined that a burning diamond and charcoal produced the same gas: carbon dioxide. The discovery convinced him that both diamond and charcoal contained the same element, which he named carbon.
Through years of research on respiration and combustion, the Lavoisiers proved that, from a chemical standpoint, the two processes were identical. The Lavoisiers designed several tests to measure breathing and understand the heat given off during respiration.
In one experiment, Antoine used his laboratory tools to measure the heat and carbon dioxide emitted from a guinea pig's exhalation. He then burned carbon to produce an equal amount of carbon dioxide to prove it created the same amount of heat.
The groundbreaking research explained why mammals have a body temperature higher than room temperature.