Calorimeter

Not to be confused with Colorimeter.

A calorimeter is a tool that measures the amount of thermal energy contained in a substance, or released in a reaction. A commonplace use is to measure heat of combustion.

The world’s first ice-calorimeter, used in1782-83, by Antoine Lavoisier and Pierre-Simon Laplace, to measure the heat generated by chemical changes. The calculations were based on Joseph Black’s discovery of latent heat. These experiments started thermochemistry.