Antoine Lavoisier

• Born: 26 August 1743
• Birthplace: Paris, France
• Died: 8 May 1794 (beheading)
• Best Known As: French chemist who proved the law of conservation of mass

Antoine Laurent Lavoisier was a French chemist whose persistence in precise experiments led to the law of conservation of mass. A Parisian aristocrat, Lavoisier studied law but went into science. He was the first to announce that air was made up of two gases -- oxygen and what he called azote (now called nitrogen) -- and by the 1780s Lavoisier was a well-known member of Europe's scientific community and a public-minded citizen of Paris. He collaborated on the influential Methods of Chemical Nomenclature (1787) and published what many consider to be the first modern chemistry textbook (1789). He also made money as an investor in a tax collecting firm, and during the French Revolution's Reign of Terror he was beheaded by anti-monarchists. Because of his achievements he is sometimes called the father of modern chemistry.

His wife, Marie-Anne Pierrette Paulze (m. 1771), was his assistant, translator and illustrator.

For more information on Antoine-Laurent Lavoisier, visit Britannica.com.

Antoine-Laurent Lavoisier

Library of Congress

[b. Paris, August 26, 1743, d. Paris, May 8, 1794]

Lavoisier used careful measurement and thoughtful experiments to turn chemistry into a science. He also explained the experiments of others, such as Joseph Priestley's discovery of oxygen and Henry Cavendish's production of water from hydrogen and oxygen. Lavoisier used the results of other chemists and his own experiments to create the modern theory of fire and to explain the role of air in combustion and respiration. He was the among the first to have a clear concept of a chemical element and the first to list the known elements. He also developed the idea of naming compounds from elements. In addition, Lavoisier was the first to use and to state clearly a conservation law for mass. For these reasons, he is known as the father of modern chemistry.

(1743-94) French chemist, performed the first studies of heat output, consumption of oxygen (which he named), and production of carbon dioxide, creating the basis of calorimetry.

The French chemist Antoine Laurent Lavoisier (1743-1794) was the founder of the modern science of chemistry and the author of the oxygen theory of combustion.

Antoine Laurent Lavoisier was born in Paris on Aug. 26, 1743, the son of an attorney at the Parlement of Paris. Lavoisier began his schooling at the Collège Mazarin in Paris at the age of 11. In his last two years (1760-1761) at the college his scientific interests were aroused. In the philosophy class he came under the tutelage of Abbé Nicolas Louis de Lacaille, a distinguished mathematician and observational astronomer who imbued the young Lavoisier with an interest in meteorological observation, an enthusiasm which never left him.

Lavoisier entered the school of law, where he received a bachelor's degree in 1763 and a licentiate in 1764. However, he continued his scientific education in his spare time. In 1764 he read his first paper to the French Academy of Sciences, on the chemical and physical properties of gypsum (hydrated calcium sulfate), and in 1766 he was awarded a gold medal by the King for an essay on the problems of urban street lighting.

In 1768 Lavoisier received a provisional appointment to the Academy of Sciences. About the same time he bought a share in the Tax Farm, a financial company which advanced the estimated tax revenue to the royal government in return for the right to collect the taxes. It was to prove a fateful step. Lavoisier consolidated his social and economic position when, in 1771, he married Marie Anne Pierrette Paulze, the 14-year-old daughter of a senior member of the Tax Farm. She was to play an important part in Lavoisier's scientific career, translating English chemical works into French for him, assisting in the laboratory, and drawing diagrams for his scientific works.

For 3 years following his entry into the Tax Farm, Lavoisier's scientific activity diminished somewhat, for much of his time was taken up with official Tax Farm business. He did, however, present one important memoir to the Academy of Sciences during this period, on the supposed conversion of water into earth by evaporation. By a very precise quantitative experiment Lavoisier showed that the "earthy" sediment produced after long-continued reflux heating of water in a glass vessel was not due to a conversion of the water into earth but rather to the gradual disintegration of the inside of the glass vessel produced by the boiling water.

Oxygen Theory of Combustion

During the summer and fall of 1772 Lavoisier turned his attention to the phenomenon of combustion, the topic on which he was to make his most significant contribution to science. He reported the results of his first experiments on combustion in a note to the academy on October 20 in which he reported that when phosphorus burned it combined with a large quantity of air to produce acid spirit of phosphorus (phosphoric acid) and that the phosphorus increased in weight on burning. In a second sealed note deposited with the academy a few weeks later (November 1) Lavoisier extended his observations and conclusions to the burning of sulfur and went on to add that "what is observed in the combustion of sulfur and phosphorus may well take place in the case of all substances that gain in weight by combustion and calcination: and I am persuaded that the increase in weight of metallic calces is due to the same cause."

During 1773 Lavoisier determined to review thoroughly the literature on air, particularly "fixed air," and to repeat many of the experiments of other workers in the field. He published an account of this review in 1774 in a book entitled Opuscules physiques et chimiques (Physical and Chemical Essays). In the course of this review he made his first full study of the work of Joseph Black, the Scottish chemist who had carried out a series of classic quantitative experiments on the mild and caustic alkalies. Black had shown that the difference between a mild alkali, for example, chalk (CaCO₃), and the caustic form, for example, quicklime (CaO), lay in the fact that the former contained "fixed air," not common air fixed in the chalk, but a distinct chemical species, carbon dioxide (CO₂), which was a constituent of the atmosphere. Lavoisier recognized that Black's fixed air was identical with the air evolved when metal calces were reduced with the charcoal and even suggested that the air which combined with metals on calcination and increased the weight might be Black's fixed air, that is, CO₂.

In the spring of 1774 Lavoisier carried out experiments on the calcination of tin and lead in sealed vessels which conclusively confirmed that the increase in weight of metals on calcination was due to combination with air. But was it combination with common atmospheric air or with only a part of atmospheric air? In October the English chemist Joseph Priestley visited Paris, where he met Lavoisier and told him of the air which he had produced by heating the red calx of mercury with a burning glass and which had supported combustion with extreme vigor. Priestley at this time was unsure of the nature of this gas, but he felt that it was an especially pure form of common air. Lavoisier carried out his own researches on this peculiar substance. The result was his famous memoir "On the Nature of the Principle Which Combines with Metals during Their Calcination and Increases Their Weight," read to the academy on April 26, 1775 (commonly referred to as the Easter Memoir). In the original memoir Lavoisier showed that the mercury calx was a true metallic calx in that it could be reduced with charcoal, giving off Black's fixed air in the process. When reduced without charcoal, it gave off an air which supported respiration and combustion in an enhanced way. He concluded that this was just a pure form of common air, and that it was the air itself "undivided, without alteration, without decomposition" which combined with metals on calcination.

After returning from Paris, Priestley took up once again his investigation of the air from mercury calx. His results now showed that this air was not just an especially pure form of common air but was "five or six times better than common air, for the purpose of respiration, inflammation, and … every other use of common air." He called the air dephlogisticated air, as he thought it was common air deprived of its phlogiston. Since it was therefore in a state to absorb a much greater quantity of phlogiston given off by burning bodies and respiring animals, the greatly enhanced combustion of substances and the greater ease of breathing in this air were explained.

The "official" version of Lavoisier's Easter Memoir did not appear until 1778. In the intervening period Lavoisier had ample time to repeat some of Priestley's latest experiments and perform some new ones of his own. In addition to studying Priestley's dephlogisticated air, he studied more thoroughly the residual air after metals had been calcined. He showed that this residual air supported neither combustion nor respiration and that approximately five volumes of this air added to one volume of the dephlogisticated air gave common atmospheric air. Common air was then a mixture of two distinct chemical species with quite different properties. Thus when the revised version of the Easter Memoir was published in 1778, Lavoisier no longer stated that the principle which combined with metals on calcination was just common air but "nothing else than the healthiest and purest part of the air" or the "eminently respirable part of the air." In the following year Lavoisier coined the name oxygen for this constituent of the air, from the Greek words meaning "acid former." He was struck by the fact that the combustion products of such nonmetals as sulfur, phosphorus, charcoal, and nitrogen were acidic. He held that all acids contained oxygen and that oxygen was therefore the acidifying principle.

Lavoisier's new theory of combustion was virtually complete. He was now ready to mount a wholesale attack on the current phlogiston theory.

Lavoisier the Public Servant

Lavoisier's researches on combustion were carried out in the midst of a very busy schedule of public and private duties, especially in connection with the Tax Farm. There were also innumerable reports for and committees of the Academy of Sciences to investigate specific problems on order of the royal government. Lavoisier, whose organizing skills were outstanding, frequently landed the task of writing up such official reports. In 1775 he was made one of four commissioners of gunpowder appointed to replace a private company, similar to the Tax Farm, which had proved unsatisfactory in supplying France with its munitions requirements. As a result of his efforts, both the quantity and quality of French gunpowder greatly improved, and it became a source of revenue for the government. His appointment to the Gunpowder Commission brought one great benefit to Lavoisier's scientific career as well. As a commissioner, he enjoyed both a house and a laboratory in the Royal Arsenal. Here he lived and worked between 1775 and 1792.

Consolidation of the New Theory

Lavoisier's chemical research between 1772 and 1778 was largely concerned with developing his own new theory of combustion. In 1783 he read to the academy his famous paper entitled "Reflections of Phlogiston," a full-scale attack on the current phlogiston theory of combustion. That year Lavoisier also began a series of experiments on the composition of water which were to prove an important capstone to his combustion theory and win many converts to it. Many investigators had been experimenting with the combination of inflammable air (hydrogen) with dephlogisticated air (oxygen) by electrically sparking mixtures of the gases. All of the researchers noted the production of water, but all interpreted the reaction in varying ways within the framework of the phlogiston theory. In cooperation with mathematician Pierre Simon de Laplace, Lavoisier synthesized water by burning jets of hydrogen and oxygen in a bell jar over mercury. The quantitative results were good enough to support the contention that water was not an element, as had been thought for over 2,000 years, but a compound of two gases, hydrogen and oxygen.

Lavoisier, together with L. B. Guyton de Morveau, Claude Louis Berthollet, and Antoine François de Fourcroy, submitted a new program for the reforms of chemical nomenclature to the academy in 1787, for there was virtually no rational system of chemical nomenclature at this time. The new system was tied inextricably to Lavoisier's new oxygen theory of chemistry. The Aristotelian elements of earth, air, fire, and water were discarded, and instead some 55 substances which could not be decomposed into simpler substances by any known chemical means were provisionally listed as elements. The elements included light; caloric (matter of heat); the principles of oxygen, hydrogen, and azote (nitrogen); carbon; sulfur; phosphorus; the yet unknown "radicals" of muriatic acid (hydrochloric acid), boracic acid, and "fluoric" acid; 17 metals; 5 earths (mainly oxides of yet unknown metals such as magnesia, barite, and strontia); three alkalies (potash, soda, and ammonia); and the "radicals" of 19 organic acids. The acids, regarded in the new system as compounds of various elements with oxygen, were given names which indicated the element involved together with the degree of oxygenation of that element, for example sulfuric and sulfurous acids, phosphoric and phosphorus acids, nitric and nitrous acids, the "ic" termination indicating acids with a higher proportion of oxygen than those with the "ous" ending. Similarly, salts of the "ic" acids were given the terminal letters "ate," as in copper sulfate, whereas the salts of the"ous" acids terminated with the suffix "ite," as in copper sulfite. The total effect of the new nomenclature can be gauged by comparing the new name "copper sulfate" with the old term "vitriol of Venus."

Lavoisier employed the new nomenclature in his Elements of Chemistry, published in 1789. This work represents the synthesis of Lavoisier's contribution to chemistry and can be considered the first modern text-book on the subject. The core of the Elements of Chemistry was the oxygen theory, and the work became a most effective vehicle for the transmission of the new doctrines. It remains a classic in the history of science.

His Physiological Studies

The relationship between combustion and respiration had long been recognized from the essential role which air played in both processes. Lavoisier was almost obliged, therefore, to extend his new theory of combustion to include the area of respiration physiology. His first memoirs on this topic were read to the Academy of Sciences in 1777, but his most significant contribution to this field was made in the winter of 1782/1783 in association with Laplace. The result of this work was published in a famous memoir, "On Heat." Lavoisier and Laplace designed an ice calorimeter apparatus for measuring the amount of heat given off during combustion or respiration. By measuring the quantity of carbon dioxide and heat produced by confining a live guinea pig in this apparatus, and by comparing the amount of heat produced when sufficient carbon was burned in the ice calorimeter to produce the same amount of carbon dioxide as that which the guinea pig exhaled, they concluded that respiration was in fact a slow combustion process. This continuous slow combustion, which they supposed took place in the lungs, enabled the living animal to maintain its body temperature above that of its surroundings, thus accounting for the puzzling phenomenon of animal heat.

Lavoisier continued these respiration experiments in 1789-1790 in cooperation with Armand Seguin. They designed an ambitious set of experiments to study the whole process of body metabolism and respiration using Seguin as a human guinea pig in the experiments. Their work was only partially completed and published because of the disruption of the Revolution; but Lavoisier's pioneering work in this field served to inspire similar research on physiological processes for generations to come.

Last Years

As the Revolution gained momentum from 1789 on, Lavoisier's world inexorably collapsed around him. Attacks mounted on the Tax Farm, and it was eventually suppressed in 1791. In 1792 Lavoisier was forced to resign from his post on the Gunpowder Commission and to move from his house and laboratory at the Royal Arsenal. On Aug. 8, 1793, all the learned societies, including the Academy of Sciences, were suppressed.

It is difficult to assess Lavoisier's own attitude to the political turmoil. Like so many intellectual liberals, he felt that the Old Regime could be reformed from the inside if only reason and moderation prevailed. Characteristically, one of his last major works was a proposal to the National Convention for the reform of French education. He tried to remain aloof from the political cockpit, no doubt fearful and uncomprehending of the violence he saw therein. However, on Nov. 24, 1793, the arrest of all the former tax gatherers was ordered. They were formally brought to trial on May 8, 1794, and convicted with summary justice of having plundered the people and the treasury of France, of having adulterated the nation's tobacco with water, and of having supplied the enemies of France with huge sums of money from the national treasury. Lavoisier, along with 27 of his former colleagues, was guillotined on the same day.

Further Reading

The best source for a study of Lavoisier is the translation of his Traité elémentaire de chimie, printed as Elements of Chemistry with an introduction by Douglas McKie, in 1965. The most comprehensive biography of Lavoisier in English is Douglas McKie, Antoine Lavoisier: Scientist, Economist, Social Reformer (1952). Henry Guerlac, Lavoisier: The Crucial Years (1961), deals with the factors which led Lavoisier to study the combustion problem. See also Sidney J. French, Torch and Crucible: The Life and Death of Antoine Lavoisier (1941). James Bryant Conant, ed., The Overthrow of the Phlogiston Theory (1955), is a clear and valuable study of this aspect of the chemical revolution.

Lavoisier, Antoine-Laurent de (1743-94). One of the founders of modern chemistry. His most important discoveries concern oxygen and the composition of air and water (see his Traité élémentaire de chimie, 1789). His many scientific and practical interests included the manufacture of gunpowder and a scheme for gas lighting. He held a post of taxfarmer, as a result of which—in spite of his liberal views—he was guillotined under the Revolution.

[Peter France]

Lavoisier, Antoine (Antoine-Laurent Lavoisier; 1743–1794), considered the father of modern French chemistry and the discoverer of oxygen. Born to a family of notaries and lawyers, Lavoisier was raised in the comfort of bourgeois Paris and attended the Collège Mazarin, where he studied literature, rhetoric, and the natural sciences. Intended for a legal career (he received his law degree in 1763 and several prizes for rhetoric), he early on moved first into mineralogy, traveling with Jean Étienne Guettard of the Academy of Sciences, and then into chemistry, following especially the public courses of the controversial Guillaume-François Rouelle at the Jardin du Roi. He was accepted at a very early on into the Academy of Sciences, of which he would be a lifelong and tireless member.

At a young age, Lavoisier felt that chemistry was a science filled with unclear names and confused theories, and he was committed to resolving it into a science as systematic as Newton's physics. From 1763 to about 1770, he slowly elaborated his famous principle that "nothing is gained and nothing is lost" in chemical reactions, that is, that conservation of mass defines the conceptual closure of chemical experiments. He also demonstrated that water is not an element by separating it into hydrogen and oxygen and then reversing the process. During the "crucial year," 1772–1773, he identified oxygen (and hydrogen) as elements and set the stage for the chemical revolution that disproved the phlogiston, or fixed-fire, theory of chemistry. In 1787 he and his disciples sealed their success with the Method of Chemical Nomenclature, a controversial reform of the field of chemistry based on Condillac's definition of a science as a perfect analytic language. Lavoisier's Elements of Chemistry of 1789 united the reformed nomenclature with the principles of closure-determined experimental observation and his definition of the chemical element. From the early 1780s he also worked with Laplace (1749–1827), studying the chemistry of respiration and theorizing that metabolism is a form of combustion. In this way he prepared the way for much of nineteenth-century biochemistry.

Lavoisier's life was not limited to chemistry, however. Although he had inherited a fortune sufficient for financial independence, he was a shy, serious young man, not given to public displays of brilliance or adept at social climbing. His marriage to the fourteen-year-old Marie Paulze, daughter of one of the members of the infamous General Farm, a quasi-governmental organization that collected the taxes from the French subjects for the crown, provided him with the social connections and the additional financial resources needed to join the oligarchy of Enlightenment meritocrats attempting to reform the French state under Louis XV (ruled 1715–1774) and Louis XVI (ruled 1774–1792). Lavoisier's training as a lawyer served him well at the tax farm and as a collaborator with Turgot (1727–1781) on proposals to reform the French economy. Dupont de Nemours (1739–1817) introduced him to the Physiocrats, and Lavoisier applied his scientific and economic theories to real-world experiments in agriculture (using experimental farms in his tax region to test the utility of crop rotation), prison reforms, analyses of the quality of the water of Paris, proposals for lighting Paris, and comparisons of hot-air versus hydrogen balloons for military observations and scientific investigations.

During the French Revolution and until the 1793 abolition of the Academy of Sciences, Lavoisier turned the sciences to the service of the republic. He was tireless in establishing a Bureau of Weights and Measures and the adoption of the metric system. He ran the in-town saltpeter factory that provided France (but only after his chemical improvements) with sufficient gunpowder to fight the counterrevolutionaries. With Condorcet (1743–1794) he proposed a structure for a secular public education, in part based on his experience of the reform of chemistry through its nomenclature: He believed that a French language freed from the confusion, superstition, and historical connotations of ancien régime ideology would create a new type of republican citizen and guarantee the economic security of the modern technological state.

He was, nonetheless, sent to the guillotine with the other fermiers généraux on 8 May 1794. His wife and chemical disciples had circulated letters and petitions to show how much the "father of French chemistry," as he was called, had been useful to the Revolution. The answer given them is famous: "the Revolution has no need of scientists." The Reign of Terror fell only three months later, and the posthumous rehabilitation of Lavoisier as the ideal citizen-scientist went hand-in-hand with the dismantling of Robespierre's (1758–1794) terrorist state.

Bibliography

Primary Sources

Lavoisier, Antoine Laurent. Elements of Chemistry. Translated by Robert Kerr. Introduction by Douglas Mc Kie. New York, 1965. This is the standard English translation of the Traitéélémentaire de chimie, 1789.

——. Oeuvres de Lavoisier. Paris, 1862. The editing of his correspondence is still not finished. This same edition is also available online at the Sorbonne's http://histsciences.univ-paris1.fr/i-corpus/lavoisier/index.php, and many of the manuscripts as well as a good overview of the location of unpublished manuscripts held around the world can be found at the Panopticon Lavoisier, established by Marco Beretta and Andrea Scotti at http://moro.imss.fi.it/lavoisier/.

Secondary Sources

Guerlac, Henry. Lavoisier: The Crucial Year. Ithaca, N.Y., 1961. The classic reading of Lavoisier's invention of modern chemistry.

Holmes, Frederic Lawrence. Lavoisier and the Chemistry of Life. Madison, Wisc., 1985. The best analysis of Lavoisier's work on animal respiration and metabolism.

Poirier, Pierre-Jean. Lavoisier, Chemist, Biologist, Economist. Translated by Rebecca Balinski. Philadelphia, 1996. Translation of Antoine Laurent de Lavoisier, 1743–1794, Paris, 1993. The best modern biography of Lavoisier in that it deals with the full scope of his scientific, technical, and public activities.

—WILDA CHRISTINE ANDERSON

A French scientist of the eighteenth century, Lavoisier was one of the founders of modern chemistry. He discovered the role of oxygen in chemical reactions.

"Lavoisier" redirects here. For other uses, see Lavoisier (disambiguation).

Antoine Lavoisier
Portrait of Monsieur Lavoisier and his Wife by Jacques-Louis David (ca. 1788)
Born	26 August 1743(1743-08-26) Paris, France
Died	8 May 1794 (aged 50) Paris, France
Influences	Guillaume-François Rouelle
Religious stance	Roman Catholic

Antoine-Laurent de Lavoisier (26 August 1743 – 8 May 1794); French pronunciation: [ɑ̃ˈtwan lɔˈʁɑ̃ də la.vwaˈzje]), the father of modern chemistry,^[1] was a French noble prominent in the histories of chemistry and biology. He stated the first version of the law of conservation of mass,^[2] recognized and named oxygen (1778) and hydrogen (1783), abolished the phlogiston theory, helped construct the metric system, wrote the first extensive list of elements, and helped to reform chemical nomenclature. He discovered that, although matter may change its form or shape, its mass always remains the same. Thus, for instance, if water is heated to steam, if salt is dissolved in water or if a piece of wood is burned to ashes, the total mass remains unchanged. He was also an investor and administrator of the "Ferme Générale" a private tax collection company; chairman of the board of the Discount Bank (later the Banque de France); and a powerful member of a number of other aristocratic administrative councils. All of these political and economic activities enabled him to fund his scientific research. At the height of the French Revolution he was accused by Marat of selling watered-down tobacco, and of other crimes, and was beheaded.^[3][4]

Contents 1 Early life 2 Contributions to chemistry 2.1 Research on gases, water, and combustion 2.2 Pioneer of stoichiometry 2.3 Analytical chemistry and chemical nomenclature 2.4 Legacy 3 Contributions to biology 4 Law and politics 5 Final days, execution, and aftermath 6 Selected writings 7 See also 8 References 9 Further reading 10 External links

Early life

Antoine Lavoisier

Born to a wealthy family in Paris, Antoine Laurent Lavoisier inherited a large fortune at the age of five with the passing of his mother.^[5] He attended the College Mazarin in 1754 to 1761, studying chemistry, botany, astronomy, and mathematics. His education was filled with the ideals of the French Enlightenment of the time, and he felt fascination for Maquois's dictionary. He attended lectures in the natural sciences. Lavoisier's devotion and passion for chemistry was largely influenced by Étienne Condillac, a prominent French scholar of the 18th century. His first chemical publication appeared in 1764. In collaboration with Jean-Étienne Guettard, Lavoisier worked on a geological survey of Alsace-Lorraine in June 1767. At the age of 25, he was elected a member of the French Academy of Sciences, France's most elite scientific society, for an essay on street lighting and in recognition for his earlier research. In 1769, he worked on the first geological map of France.

In 1771, Lavoisier at age 28, married the 13-year-old Marie-Anne Pierrette Paulze, the daughter of a co-owner of the Ferme. Over time, she proved to be a scientific colleague to her husband. She translated documents from English for him, including Richard Kirwan's Essay on Phlogiston and Joseph Priestley's research. She created many sketches and carved engravings of the laboratory instruments used by Lavoisier and his colleagues. She also edited and published Lavoisier’s memoirs (whether any English translations of those memoirs have survived is unknown as of today) and hosted parties at which eminent scientists discussed ideas and problems related to chemistry.^[6]

Contributions to chemistry

Research on gases, water, and combustion

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 also demonstrated the role of oxygen in the rusting of metal, as well as oxygen's role in animal and plant respiration. Working with Pierre-Simon Laplace, Lavoisier conducted experiments that showed that respiration was essentially a slow combustion of organic material using inhaled oxygen. Lavoisier's explanation of combustion disproved the phlogiston theory, which postulated that materials released a substance called phlogiston when they burned.

Lavoisier also discovered that Henry Cavendish's "inflammable air", which Lavoisier had termed hydrogen (Greek for "water-former"), combined with oxygen to produce a dew which, as Joseph Priestley had reported, appeared to be water. Lavoisier's work was partly based on the research of Priestley. However, he tried to take credit for Priestley's discoveries. This tendency to use the results of others without acknowledgment, then draw conclusions of his own, is said to be 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 demonstrated that the "air" responsible for combustion was also the source of acidity. In 1779, he named this part of the air "oxygen" (Greek for "becoming sharp" because he claimed that the sharp taste of acids came from oxygen), and the other "azote" (Greek for "no life"). In "Réflexions sur le Phlogistique" ("Reflections on Phlogiston," 1783), Lavoisier showed the phlogiston theory to be inconsistent.

Pioneer of stoichiometry

Laboratory instruments used by Lavoisier circa 1780s

Lavoisier's researches included some of the first truly quantitative chemical experiments. He carefully weighed the reactants and products in a chemical reaction, which was a crucial step in the advancement of chemistry. He showed that, although matter can change its state in a chemical reaction, the total mass of matter is the same at the end as at the beginning of every chemical change. These experiments supported the law of conservation of mass, which Lavoisier was the first to state,^[2] although Mikhail Lomonosov (1711-1765) had previously expressed similar ideas in 1748 and proved them in experiments. Others who anticipated the work of Lavoisier include Joseph Black (1728-1799), Henry Cavendish (1731-1810), and Jean Rey (1583-1645).

Analytical chemistry and chemical nomenclature

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 (Elementary Treatise on 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.

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.

Combustion generated by focusing sunlight over flammable materials using lenses, an experiment conducted by Lavoisier in the 1770s

Detail of picture of a combustion experiment

Legacy

Constant pressure calorimeter , engraving made by madame Lavoisier for thermochemistry experiments.

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 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 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 the 18th century.^[7]

Lavoisier conducting an experiment on respiration in the 1770s.

Contributions to biology

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 center 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.^[8]

Law and politics

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

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.^[9] Lavoisier was tried, convicted, and guillotined on 8 May in Paris, at the age of 50.

Lavoisier was actually one of the few liberals in his position. One of his actions that may 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." Marat 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 course of justice can not be delayed."^[10]

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 une autre pareille 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.")^[11][12]

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 (photograph, right) and on the façade of the Cour Napoléon of the Louvre.

Selected writings

• 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

See also

• Caloric theory
• List of independent discoveries#18th century
• Timeline of hydrogen technologies

References

1. ^ "Lavoisier, Antoine." Encyclopædia Britannica. 2007. Encyclopædia Britannica Online. 24 July 2007.
2. ^ ^{a b} Schwinger, Julian (1986). Einstein's Legacy. New York: Scientific American Library. pp. 93. ISBN 0-7167-5011-2. 
3. ^ Ihde, Aaron (1964). The Development of Modern Chemistry. Harper & Row. p. 86. 
4. ^ Moore, F. J. (1918). A History of Chemistry. New York: McGraw-Hill. p. 47. http://books.google.com/books?id=ROQIAAAAIAAJ&pg=PA47&dq=history+chemistry+moore+lavoisier. 
5. ^  "Antoine-Laurent Lavoisier". Catholic Encyclopedia. New York: Robert Appleton Company. 1913. http://en.wikisource.org/wiki/Catholic_Encyclopedia_(1913)/Antoine-Laurent_Lavoisier. 
6. ^ Eagle, Cassandra T.; Jennifer Sloan (1998). "Marie Anne Paulze Lavoisier: The Mother of Modern Chemistry" (PDF). The Chemical Educator 3 (5): 1 – 18. doi:10.1007/s00897980249a. http://www.springerlink.com/content/x14v35m5n8822v42/fulltext.pdf. Retrieved 2007-12-14. 
7. ^ Charles C. Gillespie, Foreword to Lavoisier by Jean-Pierre Poirier, University of Pennsylvania Press, English Edition, 1996.
8. ^ Is a Calorie a Calorie? American Journal of Clinical Nutrition, Vol. 79, No. 5, 899S–906S, May 2004
9. ^ O'Connor, J. J.; Robertson, E. F. (2006-09-26). "Lagrange Biography". http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Lagrange.html. Retrieved 2006-04-20. "In September 1793 a law was passed ordering the arrest of all foreigners born in enemy countries and all their property to be confiscated. Lavoisier intervened on behalf of Lagrange, who certainly fell under the terms of the law, and he was granted an exception. On 8 May 1794, after a trial that lasted less than a day, a revolutionary tribunal condemned Lavoisier, who had saved Lagrange from arrest, and 27 others to death. Lagrange said on the death of Lavoisier, who was guillotined on the afternoon of the day of his trial" 
10. ^ Commenting on this quotation, Denis Duveen, an English expert on Lavoiser and a collector of his works, wrote that "it is pretty certain that it was never uttered." For Duveen's evidence, see the following: Duveen, Denis I. (February 1954). "Antoine Laurent Lavoisier and the French Revolution". Journal of Chemical Education 31: 60 – 65. .
11. ^ Delambre, Jean-Baptiste (1867). "Notice sur la vie et les ouvrages de M. le Comte J.-L. Lagrange". in Serret, J. A.. Oeuvres de Lagrande. 1. pp. xl. 
12. ^ Guerlac, Henry (1973). Antoine-Laurent Lavoisier - Chemist and Revolutionary. New York: Charles Scribner's Sons. pp. 130. 

Further reading

Lavoisier, by Jacques-Léonard Maillet, ca 1853, among culture heroes in the Louvre's Cour Napoléon

• Berthelot, M. (1890). La révolution chimique: Lavoisier. Paris: Alcan. 

• Daumas, M. (1955). Lavoisier, théoricien et expérimentateur. Paris: Presses Universitaires de France. 

• Donovan, Arthur (1993). Antoine Lavoisier: Science, Administration, and Revolution. Cambridge, England: Cambridge University Press. 

• Grey, Vivian (1982). The Chemist Who Lost His Head: The Story of Antoine Lavoisier. Coward, McCann & Geoghegan, Inc.. 

• Guerlac, Henry (1961). Lavoisier - The Crucial Year. Ithaca, New York: Cornell University Press. 

• Holmes, Frederic Lawrence (1985). Lavoisier and the Chemistry of Life. Madison, Wisconsin: University of Wisconsin Press. 

• Holmes, Frederic Lawrence (1998). Antoine Lavoisier - The Next Crucial Year, or the Sources of his Quantitative Method in Chemistry. Princeton University Press. 

• Jackson, Joe (2005). A World on Fire: A Heretic, An Aristocrat And The Race to Discover Oxygen. Viking. 

• Johnson, Horton A. (2008). "Revolutionary Instruments, Lavoisier's Tools as Objets d'Art". Chemical Heritage 26 (1): 30 – 35. 

• Kelly, Jack (2004). Gunpowder: Alchemy, Bombards, & Pyrotechnics. Basic Books. ISBN 0-465-03718-6. 

• McKie, Douglas (1935). Antoine Lavoisier: The Father of Modern Chemistry. Philadelphia: J. P. Lippincott Company. 

• McKie, Douglas (1952). Antoine Lavoisier: Scientist, Economist, Social Reformer. New York: Henry Schuman. 

• Poirier, Jean-Pierre (1996, English edition). Lavoisier. University of Pennsylvania Press. 

• Scerri, Eric (2007). The Periodic Table: Its Story and Its Significance. Oxford University Press. 

• Smartt Bell, Madison (2005). Lavoisier in the Year One: The Birth of a New Science in an Age of Revolution. Atlas Books, W. W. Norton. 

External links

Wikiquote has a collection of quotations related to: Antoine Lavoisier

Wikimedia Commons has media related to: Antoine Lavoisier

Wikisource has the text of the 1911 Encyclopædia Britannica article Lavoisier, Antoine Laurent.

• Antoine Laurent Lavoisier
• A virtual museum of Antoine Lavoisier
• Antoine Lavoisier - Chemical Achievers profile.
• Who was the first to classify materials as "compounds"? - Fred Senese
• (French) The Complete Works of Lavoisier edited by Pietro Corsi (Oxford University) and Patrice Bret (CNRS)
• Radio 4 program on the discovery of oxygen by the BBC
• Location of Lavoisier's laboratory in Paris

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This article incorporates text from the public-domain Catholic Encyclopedia of 1913.

Persondata
NAME	Lavoisier, Antoine
ALTERNATIVE NAMES	de Lavoisier, Antoine-Laurent
SHORT DESCRIPTION	chemist, economist and nobleman.
DATE OF BIRTH	26 August 1743(1743-08-26)
PLACE OF BIRTH	Paris, France
DATE OF DEATH	8 May 1794
PLACE OF DEATH	Paris, France

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