Lavoisier, Antoine-Laurent de

The French Antoine-Laurent de Lavoisier (1743 - 1794), son from a wealthy family of the nobility, was a chemist.

His researches included some of the first truly quantitative chemical experiments. In 1774, he showed that the total mass of matter is the same at the end as at the beginning of every chemical change.

In his first experiments on combustion he showed that phosphorus increased in weight on burning. He found that oxygen plays a role in combustion, opposing the prior phlogiston theory of combustion. He named oxygen, recognizing it as an element, and also recognized hydrogen as an element.

In cooperation with Pierre-Simon de Laplace, Lavoisier synthesized water by burning hydrogen and oxygen in a bell jar, thus proving that water was not an element, but a compound of hydrogen and oxygen.

Experiments on respiration physiology led him to conclude that respiratory gas exchange is a combustion, like that of a candle burning.