Antoine Laurent Lavoisier 1743-1794

French Chemist

Lavoisier is best known for his revolutionary theory of oxidation -- the now accepted theory that when substances burn, they combine with oxygen. This theory replaced earlier theories, such as the Phlogiston theory, which held that substances lost something when they burned. Lavoisier also championed the principle of conservation of matter -- that matter may be recombined in chemical reactions but it is never created or destroyed. Thus, the weight of substance going into a chemical reaction always equal the weight of the substances coming out.

Lavoisier worked on a number of practical projects including improvements in the manufacture of gun powder. In fact, it was his work that made it possible for France to sell gun powder to the American colonies in the quantities needed for their war of independence.

Lavoisier entertained visitors such as the British chemist, Jospeh Priestley, and the American scientist and diplomat, Benjamin Franklin. Lavoisier made a dangerous enemy in the French revolutionist, Marat, who had Lavoisier guillotined during the French Revolution. Lagrange said, "It took but a moment to cut off his head but it will take a century to produce another like it."