The Weight of Heat

The chemist Lavoisier actually tried to weigh heat; he found it was weightless.

Lavoisier on Constant Mass

In 1789, Lavoisier showed that the total mass during the course of a chemical reaction is unchanged. Rather the atoms simply “reorganize” themselves, kind of like the reshuffling of deck or cards.

Lavoisier’s 33 Elements

In 1789, Lavoisier published An Elementary Treatise on Chemistry where he describes 33 elements. The list begins with caloric and continues with light, oxygen, nitrogen and hydrogen.

Heat as “Caloric”

Pierre-Simon Laplace (1749-1827) imagined heat to be a fluid composed of particles, deemed by Antoine Lavoisier (1743-1794) as “caloric”.