User:Yottie/Antoine Lavoisier

Antoine Lavoisier
"Father of modern chemistry"
Born(1743-08-26)26 August 1743
Paris, France
Died8 May 1794(1794-05-08) (aged 50)
Paris, France
Scientific career
Fieldsbiologist, chemist
InfluencesGuillaume-François Rouelle
InfluencedAsfandyar Quereshi

Antoine-Laurent de Lavoisier (August 26, 1743 – May 8, 1794; pronounced [ɑ̃ˈtwan lɔˈʁɑ̃ də la.vwaˈzje]), was a French nobleman famous for his work in chemistry, finance, biology, and economics. He is sometimes called the father of modern chemistry. He created the first version of the law of conservation of mass. He found and named oxygen (1778) and hydrogen (1783). He demonstrated the phlogiston theory was wrong, he established the metric system, he wrote the first long list of elements, and he helped to change chemical nomenclature. He was also an investor and administrator of a private tax collection company called the Ferme Générale. He was chairman of the board of the Discount Bank (which became the Banque de France). He was a powerful member of many other aristocratic administrative councils. These political and economic activities helped him pay for his scientific research. However, as he was important in the French government before the revolution, he was beheaded in 1794.

Early life change

 
Portrait of Antoine-Laurent Lavoisier and his wife by Jacques-Louis David, around 1788

Antoine Laurent Lavoisier was born in a rich family in Paris. He inherited a lot of money when he was five, when his mother died. He went to Collège Mazarin between 1754 and 1761. He studied chemistry, botany, astronomy, and mathematics. The ideas of French Enlightenment were important in his education. Maquois' dictionary fascinated him. Between 1761 and 1763, he studied law at the University of Paris. He received his Bachelor of Law in 1763. At the same time, he also attended lectures in the natural sciences. Étienne Condillac, an important French scholar of the 18th century, influenced Lavoisier's devotion and passion for chemistry. His first chemical publication was in 1764. Lavoisier did a geological survey of Alsace-Lorraine with Jean-Étienne Guettard in 1767. When he was 25, he became a member of the French Academy of Sciences, the most important scientific society in France. He wrote an essay on street lighting and the academy also recognised his earlier research. In 1769, he worked on the first geological map of France.

In 1771, Lavoisier married Marie-Anne Pierrette Paulze, the daughter of a co-owner of the Ferme Générale. She was only 13 years old. Eventually, she became a scientific colleague to her husband. She translated English documents for him such as Richard Kirwan's Essay on Phlogiston and Joseph Priestley's research. She made many sketches and carved engravings of the laboratory instruments used by Lavoisier and his colleagues. She also edited and published Lavoisier’s memoirs.

Contributions to chemistry change

Research on gases, water, and combustion change

 
Antoine Lavoisier's famous phlogiston experiment. Engraving by Mme Lavoisier in the 1780s taken from Traité élémentaire de chimie (Elementary treatise on chemistry)
 
The work of Lavoisier was translated in Japan in the 1840s, through the process of Rangaku. Page from Udagawa Yōan's 1840 Seimi Kaisō

Lavoisier did many important experiments in thermodynamics and the nature of combustion, or burning. With these experiments, he showed that burning something needs oxygen. (He called the gas Oxygen. This means "acid former", as he believed that all acids had to contain oxygen, but this isn't true). Lavoisier also showed the role of oxygen in the rusting of metal, and oxygen's role in the respiration of animals and plants. Lavoisier worked with Pierre-Simon Laplace; with experiments they showed that respiration was simply a slow combustion of organic material by using inhaled oxygen. By explaining combustion, Lavoisier showed the phlogiston theory was wrong (the theory said that everything released a substance called phlogiston when they burned).

Lavoisier also discovered that Henry Cavendish's "inflammable air" with oxygen produced a dew Joseph Priestley said it seemed to be water. Lavoisier called the 'inflammable air" hydrogen (Greek for "water-former"). Lavoisier's used Priestley's research to do his own experiments. He told people he had made the discoveries before Priestley. He often used the results of others without acknowledgment and he published his own results. This is a notorious characteristic of Lavoisier. In Sur la combustion en général ("On Combustion in general," 1777) and Considérations Générales sur la Nature des Acides ("General Considerations on the Nature of Acids," 1778), he showed that the air that caused combustion was also the source of acidity. In 1779, he called this part of the air "oxygen" (Greek for "becoming sharp". He said that the sharp taste of acids came from oxygen), He called the other part azote (Greek for "no life" - Nitrogen in English). In Réflexions sur la Phlogistique ("Reflections on Phlogiston," 1783), Lavoisier showed inconsistencies in the phlogiston theory.

Pioneer of stoichiometry change

Lavoisier's did some of the first quantitative chemical experiments. He carefully weighed products in chemical reactions. This was an important part of the advancement of chemistry. He showed that there is as much matter before and after a chemical change even if matter can change state in a reaction. These experiments meant the law of conservation of mass was correct (Lavoisier was the first to say this, but Mikhail Lomonosov (1711-1765) had similar ideas before him, in 1748. He even proved them in experiments).

Analytical chemistry and chemical nomenclature change

Lavoisier investigated the composition of water and air, which at the time were considered elements. He determined that the components of water were oxygen and hydrogen, and that air was a mixture of gases, primarily nitrogen and oxygen. With the French chemists Claude-Louis Berthollet, Antoine Fourcroy and Guyton de Morveau, Lavoisier devised a systematic chemical nomenclature. He described it in Méthode de nomenclature chimique (Method of Chemical Nomenclature, 1787). This system facilitated communication of discoveries between chemists of different backgrounds and is still largely in use today, including names such as sulfuric acid, sulfates, and sulfites.

Lavoisier's Traité Élémentaire de Chimie (Treatise of Elementary Chemistry, 1789, translated into English by Scotsman Robert Kerr) is considered to be the first modern chemistry textbook. It presented a unified view of new theories of chemistry, contained a clear statement of the law of conservation of mass, and denied the existence of phlogiston. This text clarified the concept of an element as a substance that could not be broken down by any known method of chemical analysis, and presented Lavoisier's theory of the formation of chemical compounds from elements.

His Traité Élémentaire contained a list of elements that included oxygen, nitrogen, hydrogen, phosphorus, mercury, zinc, and sulfur. His list, however, also included light and caloric, which he incorrectly believed to be material substances.

While many leading chemists of the time refused to accept Lavoisier's new ideas, the Traité Élémentaire was sufficiently sound to convince the next generation.

Legacy change

Lavoisier's fundamental contributions to chemistry were a result of a conscious effort to fit all experiments into the framework of a single theory. He established the consistent use of the chemical balance, used oxygen to overthrow the phlogiston theory, and developed a new system of chemical nomenclature which held that oxygen was an essential constituent of all acids (which later turned out to be erroneous). Lavoisier also did early research in physical chemistry and thermodynamics in joint experiments with Laplace. They used a calorimeter to estimate the heat evolved per unit of carbon dioxide produced, eventually finding the same ratio for a flame and animals, indicating that animals produced energy by a type of combustion reaction.

Lavoisier also contributed to early ideas on composition and chemical changes by stating the radical theory, believing that radicals, which function as a single group in a chemical process, combine with oxygen in reactions. He also introduced the possibility of allotropy in chemical elements when he discovered that diamond is a crystalline form of carbon.

However, much to his professional detriment, Lavoisier actually discovered no new substances, devised no really novel apparatus, and worked out no improved methods of preparation. He was essentially a theorist, and his great merit lay in the capacity of taking over experimental work that others had carried out--without always, unfortunately, adequately recognizing their claims--and by a rigorous logical procedure, reinforced by his own quantitative experiments, of expounding the true explanation of the results. He completed the work of Black, Priestley and Cavendish, and gave a correct explanation of their experiments.

Overall, his contributions are considered the most important in advancing chemistry to the level reached in physics and mathematics during 18th century.


Contributions to biology change

 
Lavoisier conducting an experiment on respiration in the 1770s

Lavoisier used a calorimeter to measure heat production as a result of respiration in a guinea pig. The outer shell of the calorimeter was packed with snow, which melted to maintain a constant temperature of 0 °C around an inner shell filled with ice. The guinea pig in the centre of the chamber produced heat which melted the ice. The water that flowed out of the calorimeter was collected and weighed. Lavoisier found that 1 kg of melted ice corresponded to 80 kcal of heat production by the guinea pig. Lavoisier concluded, "la respiration est donc une combustion", that is, respiratory gas exchange is a combustion, like that of a candle burning.

Law and politics change

Lavoisier received a law degree and was admitted to the bar, but never practiced as a lawyer. He did become interested in French politics, and at the age of 26 he obtained a position as a tax collector in the Ferme Générale, a tax farming company, where he attempted to introduce reforms in the French monetary and taxation system to help the peasants. While in government work, he helped develop the metric system to secure uniformity of weights and measures throughout France.

Final days, execution, and aftermath change

 
Statue of Lavoisier, at Hôtel de Ville, Paris

As one of twenty-eight French tax collectors and a powerful figure in the unpopular Ferme Générale, Lavoisier was branded a traitor during the Reign of Terror by French Revolutionists in 1794. Lavoisier had also intervened on behalf of a number of foreign-born scientists including mathematician Joseph Louis Lagrange, granting them exception to a mandate stripping all foreigners of possessions and freedom. Lavoisier was tried, convicted, and guillotined on May 8 in Paris, at the age of 50.

Lavoisier was actually one of the few liberals in his position. One of his actions that might have sealed his fate was a clash a few years earlier with the young Jean-Paul Marat whom he dismissed curtly after being presented with a preposterous 'scientific invention', but who subsequently became a leading revolutionary and one of the French Revolution's more extreme "professional common men."

An appeal to spare his life so that he could continue his experiments was cut short by the judge: "The Republic needs neither scientists nor chemists; the trial can not be restrained."

Lavoisier's importance to science was expressed by Lagrange who lamented the beheading by saying: "Cela leur a pris seulement un instant pour lui couper la tête, mais la France pourrait ne pas en produire un autre pareil en un siècle." ("It took them only an instant to cut off his head, but France may not produce another like it in a century.")

One and a half years following his death, Lavoisier was exonerated by the French government. When his private belongings were delivered to his widow, a brief note was included reading "To the widow of Lavoisier, who was falsely convicted."

About a century after his death, a statue of Lavoisier was erected in Paris. It was later discovered that the sculptor had not actually copied Lavoisier's head for the statue, but used a spare head of the Marquis de Condorcet, the Secretary of the Academy of Sciences during Lavoisier's last years. Lack of money prevented alterations being made. The statue was melted down during the Second World War and has not since been replaced. However, one of the main " lycées" (highschools) in Paris and a street in the 8th arrondissement are named after Lavoisier, and statues of him are found on the Hôtel de Ville (illustration, right) and on the façade of the Cour Napoléon of the Louvre.

Selected writings change

  • Lavoisier, Antoine (1789). Traité élémentaire de chimie, présenté dans un ordre nouveau et d'après les découvertes modernes. Paris: Chez Cuchet. - Reprinted 1965, Bruxelles: Cultures et Civilisations
  • Lavoisier, Antoine (1965). Elements of Chemistry. New York: Dover. - Reprint of Robert Kerr's English translation of 1790