French chemist, born in Paris on August 27, 1743 and died, in the same city, in the middle of the revolutionary fever, guillotined on 8 May 1794.
Member of a well-to-do family, studied at the College Mazarin, and by paternal influence holds a PhD in law in 1764. He soon demonstrated their skills for natural sciences: unveiled with some work on public lighting and the preparation of a mineralogical atlas of France. In 1768, at just 25 years old, he was admitted to the Academy of Sciences as chemical Assistant. Man ambitious, he realized that their scientific skills could bring him a position of favor at the French court. He was later named little asentista, Member of the Ferme Générale, corporation that provided money to the Crown in Exchange for tax citizens. In 1771 he married the daughter of the director of the company of Indies Jaime Paulze, who had 14 years of age.
In 1775 he was appointed inspector of the manufacture of gunpowder and set up his laboratory at the Arsenal, a building that became the first Science Center in Paris (which was burned during the Paris commune), and which was attended by numerous scientists foreigners such as Franklin, Priestley and Watt. He was also a member of the Committee of agriculture and director of the Academy of Sciences in 1785, Member of the House of Orléans in 1787 and alternate Deputy to the States-General in 1789. In 1791 he was appointed Treasurer of the Academy and Secretary of the Committee for the unification of weights and measures, which gave birth to the metric system.
On August 8, 1793, the Revolutionary National Convention ordered the removal of all the academies and literary societies of the State, and on 24 November the same year moved the fermiers were arrested. On May 8, 1894 he was sentenced to death, and executed on the guillotine that same day. His friend and collaborator Lagrange said: "enough time to make this head, and maybe they will not suffice a hundred years to look for other similar".
The greatest achievement of Lavoisier was the systematic introduction in the chemistry of the quantitative method, i.e., weigh it and measure it all, so it is considered founded as the father of modern chemistry.
One of his first experiments was to introduce a certain amount of water in a very large glass sealed container and subjecting it to boiling for several days. The steam produced is condensed in the upper part of the container and fell towards the bottom, where went to a boil. When the bottle is finally cooled, it found that there was a small amount of earthy posed in the background. The experiment had been undertaken many times from century XVI, and the scientists who had done it concluded invariably that water had been transformed on Earth by condensation. Lavoisier was able to separate the land of water and showed that the amount of water from the container had not changed, so that the sediment could only come from the walls of the container. Indeed, once heavy bottle found a decrease in your weight equivalent to the grounds, which showed, on the one hand, that there was no land of water, and on the other the law of conservation of matter.
The best discovery of this scientist was the theory of the oxidation. The theory then current, due to Stahl and known as the Phlogiston theory, supposed that when a metal is oxidized or calcining it loses some of its weight, which corresponds to the Phlogiston, transferable reagent principle whose loss produces the limes. Lavoisier introduced in 1781 a piece of Tin in an airtight container and submitted it to the action of the fire, after which found that the weight of the set had not changed, but metal had won it. The increase in weight could only come from the air in the bottle, which rightly identified with air desflogisticado newly discovered by Priestley and who baptized as oxigenium, according to the - mistaken - belief that this element interfered in the formation of acids (oxys genea). A similar experiment carried out with mercury led him to conclude that the metals were simple elements and the limes or oxide compounds of metal and oxygen, which showed years later H. Davy. In addition, managed to separate the two main components of air, thus concluding that "air is a mixture of two different gases: the vital air (oxygen) and the Skunk or Azot (nitrogen), without having nothing to do with the Phlogiston in its composition".
Another chemical element which gave name was hydrogen, name that you verify that the water (hydros) was composed of oxygen and fuel gas discovered by Cavendish.
It also showed that animal respiration involves the absorption of oxygen in the lungs and the release of carbon dioxide, i.e., a slow food oxidation. He identified the composition of the diamond as pure carbon and established the composition of the carbon dioxide. It showed that with the reduction of metal oxides oxygen, and established the law of thermodynamics chemical that says that the heat of formation of a compound is exactly the same as the heat of decomposition, except for the fact that in one case is absorbed and the other follows along with Laplace. It also showed that sulfuric and phosphoric acids were the Union of sulfur and phosphorus with oxygen, and that their weights were the same of their components.
His wife, possessing great intelligence, was strongly interested in the work of Lavoisier, for translating several works of English scholars, some of them published in French, the Kirwan on the Phlogiston, accompanied by a refutation of his theories by Lavoisier.
He was accused after his death have made his many discoveries due to other scientists, without even citing its origin. However, there is no doubt that it was he who knew how to make a coherent scientific theory of all data.
In addition to the usual publications in journals and proceedings of the scientific societies of the time, published Opuscules physiques et chimiques (Paris, 1774), Nouvelles recherches sur l'existence d' a fluide elastique (Paris, 1775), Instruction sur l' établissement des nitrieres sur et fabrication du salpetre, etc. (Paris, 1777); RapPort des commissaires charges par le Roi de l' test du magnetisme animal (Paris, 1784); Méthode de nomenclature chimique, etc. (Paris, 1787, in collaboration with other scientists). After his death, his wife published traité elemetaire de chimie (Paris, 1805).