December 9, 1748, Talloires (Duchy of Savoy) – November 6, 1822, Arcueil (France)
In 1770, he graduated in Medicine in Turin (Italy) and, two years later, he moved to Paris, where he studied Chemistry. Being the apprentice of Theodore Tronchin, a teacher in medical practices well recognized by the upper classes, and with friends such as Voltaire, Rousseau, and Diderot, he earns significant income that allows him to continue studying Chemistry.
In 1778, he obtained a second doctorate, in this case, in Medicine. Also, that year he received his French citizenship through his marriage to Margurite de Baur.
In 1780, with a career full of publications, he was elected a member of the Académie des Sciences. That same year, his investigations with hydrocyanic (prussic) acid and hydrocyanic acid led him to disagree with Antoine Lavoisier on the question that oxygen is essential in all acids.
Four years later, he served as director of the Manufacture des Gobelins, the famous royal tapestry-making workshops. It is here that he discovers the bleaching properties of chlorine and designs a procedure for whitening fabrics using a solution of sodium hypochlorite, "L'eau de Javel" also known as bleach.
In 1786, based on Antoine Lavoisier's theory, he carried out chemical pneumatics experiments and, a year later, together with Louis-Bernard Guyton de Morveau, Antoine Lavoisier, and Antoine-François de Fourcroy, published "Méthode de Nomenclature Chimique" (Method of Chemical Nomenclature), which laid the foundations for modern chemical nomenclature.
In 1789, together with Fourcroy and Guyton de Moreau, he created the journal "Annales de Chimie" (Annals of Chemistry) and the committee in charge of revising chemical nomenclature.
In 1791, he published “Éléments de l'Art de la Teinture” (Elements of the Art of Dyeing), with the results of his research during his time at the “Manufacture des Gobelins”. At the same time, he became Professor of Chemistry at the École Normale Supérieure, and, after 1794, at the École Polytechnique.
On the other hand, accompanied by his friend Gaspard Monge, he will be one of the government commissioners for the search for objects of science and art from the countries conquered by the armies of the Republic.
In Italy, he meets the young general Bonaparte and becomes part of the team of scientists who, in 1798, accompanied Napoleon to Egypt, where he studied the properties of natural hydrated sodium carbonate. That same year, on August 20, he is elected vice president of the Physics Section of the Egypt Institute and, in June of the following year, he will become president. It is during his stay that he elaborates his theory on chemical affinities as a result of an exploration of the Natron lakes. In 1799, he left Egypt and regained his chair at the National Institute in Paris.
In 1802, he became the president of the commission in charge of organizing "Description de L'Egypte" (Description of Egypt).
In 1803, he published "Recherche sur les lois des affinités chimiques" (Research on the laws of chemical affinities) and "Essai de statistique chimique" (Essays on Chemical Statistics). In this last book, he first defined the concept of "chemical equilibrium" by proposing a law of indefinite proportions for chemical combinations, as opposed to Joseph Proust's law of definite proportions.
In this regard, his discussion for 9 years (1799-1808) on this subject is well known, which ended up proving Lavoisier right by demonstrating that the combination ratios between the components do not depend on their masses but rather are constant.
His contributions to science are massive and he had a great influence on another scientist, his disciple and protégé, Louis Joseph Gay-Lussac.
He received the title of Count, was made a Grand Officer of the Legion of Honor, and elected a Senator.
