Public money for science was scarce, so I used my own wealth to open a sophisticated laboratory for aspiring scientists, and pushed for public science education through the Lycée and the Musée des Arts et Métiers.
In 1773 I reviewed the whole literature on air and repeated others' experiments, publishing the study in 1774 as Opuscules physiques et chimiques — where I first studied Joseph Black's fixed air in full.
As Secretary of the Royal Commission on Agriculture I ran an experimental farm in the Sologne for ten years, introducing new crops and livestock, and reported in 1788 that the tax system blocked reform.
I put science to work for the city: an essay on street lighting (gold medal, 1766), an aqueduct and Seine water purification, ventilation for the rebuilt Hôtel-Dieu hospital, and prison hygiene investigations.
From 1775 I served as one of four commissioners of gunpowder, replacing a failing private company; French gunpowder improved in quantity and quality and became a revenue source for the state.
My research method was to make every experiment answer to one framework and to keep balance sheets for all of it — accuracy in experiment tied to rigour of reasoning, which is what turned chemistry into a science.
In 1789 I published the Traité élémentaire de chimie, which brought my oxygen theory, the conservation of mass and the new nomenclature into one book for teaching and learning the new chemistry.
In 1787, with Guyton de Morveau, Berthollet and Fourcroy, I gave chemistry a rational naming system: elements listed by what cannot be decomposed, and compounds named by their composition and degree of oxygenation.
In the winter of 1782–1783 Laplace and I designed an ice calorimeter and used it to measure the heat given off by combustion and by a living animal, published in our memoir "On Heat".
From my calorimeter research with Laplace I concluded that breathing is a slow combustion — the same chemistry as a burning candle — which explained how animals keep their bodies warmer than their surroundings.
