ABSTRACT
Young Antoine Lavoisier showed mathematical ability, but his chief interest lay in chemistry, especially in applied chemistry. Later on he became Director of the nitre and gunpowder factories, a post for which he was eminently qualified by his knowledge of chemistry and his insight into practical affairs. Lavoisier's methods and views exercised a potent influence, and helped to bring chemical science to something like a position of equal rank with physics. This was largely due to the extension of exact quantitative methods, which chemistry owes to him and to his predecessor, Black. For quantitative chemistry would be impossible without the postulate that matter is neither created nor annihilated, but remains constant in quantity, throughout all processes of chemical change. The first chemist of distinction who definitely sided with Lavoisier in the campaign against the phlogiston theory was Berthollet, whose researches on chemical affinity were of great importance in the subsequent development of chemistry.
