Used with
permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA,
http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps
Antoine Laurent Lavoisier (1743-94) was a French chemist whose work in combustion showed that substances gain weight when burned, and the air they burn in loses weight, now known as the law of conservation of mass. He stated that air was composed of two gases, one of which supported combustion (Priestley's oxygen) and the other of which was inert, nitrogen. He made a list of elements then known and started the practice to name compounds after their constituent parts. His life was cut short by the guillotine during the French Revolution.