French chemist.

Elected to the Academy of Sciences at the age of 25, Lavoisier played a large part in the establishment of the metric system. He discovered, through a series of experiments, what happened during combustion. He concluded that air is made up of a mixture of gases and realised that combustion is a process in which the burning substance combines with a component of the air, a gas, which he termed 'oxygine'.

In 1783 he showed that water was not an element, as was commonly thought, but was in fact a compound consisting of hydrogen and oxygen. He was the first person to make a clear distinction between an element and a compound. Through his work Lavoisier laid the foundations for modern day quantitative organic chemistry.

In 1787 he collaborated on the introduction of a new system of chemical nomenclature, a system still in use today. He was guillotined in Paris on 8 May 1794 at the height of the French Revolution's Reign of Terror.