Antoine-Laurent de Lavoisier ( / l ə ˈ v w ɑː z i eɪ / lə- VWAH -zee-ay ; French: [ɑ̃twan lɔʁɑ̃ də lavwazje] ; 26 August 1743 – 8 May 1794), also known as Antoine Lavoisier after the French Revolution, was a French nobleman and chemist. He played a major role in the chemical revolution of the 18th century and greatly influenced the history of chemistry and biology.

It is widely believed that Lavoisier’s major achievements in chemistry came from shifting the science from describing things to using numbers for precise measurements.

Lavoisier is known for discovering how oxygen works in combustion, which challenged the earlier phlogiston theory. He named oxygen (1778) and recognized it as an element. He also identified hydrogen as an element (1783). Using more accurate measurements, he supported the idea that matter in a closed system may change form but always keeps the same mass (now called the law of conservation of mass). This led to the creation of balanced chemical equations still used today.

Lavoisier helped develop the metric system, created the first detailed list of elements, and predicted the existence of silicon. He also worked to improve chemical naming systems.

His wife and laboratory assistant, Marie-Anne Paulze Lavoisier, became a respected chemist and helped develop the metric system.

Lavoisier was a powerful member of aristocratic councils and managed the Ferme générale, a tax collection system. The Ferme générale was widely disliked because it took profits from the state, kept contracts secret, and used violent enforcement. These roles allowed him to fund his scientific work. During the French Revolution, he was accused of tax fraud and selling poor-quality tobacco. Despite pleas to save his life due to his scientific contributions, he was executed by guillotine. A year and a half later, the French government cleared him of guilt.

Biography

Antoine-Laurent Lavoisier was born on August 26, 1743, in Paris, France. He was the son of an attorney who worked for the Parlement of Paris. When Lavoisier was five years old, his mother died, and he inherited a large fortune. He began his education at the Collège des Quatre-Nations, also known as the Collège Mazarin, in Paris in 1754 when he was 11 years old. During his final two years at the school (1760–1761), he became interested in science and studied subjects such as chemistry, botany, astronomy, and mathematics. He also studied under Abbé Nicolas Louis de Lacaille, a respected mathematician and astronomer who taught him about weather observation.

Lavoisier later studied law and earned a bachelor’s degree in 1763 and a licentiate in 1764. Although he received a law degree and was admitted to the bar, he never practiced as a lawyer. Instead, he continued studying science in his free time. His education was influenced by the ideas of the French Enlightenment, and he was especially interested in a chemistry dictionary written by Pierre Macquer. He attended science lectures and was inspired by Étienne Condillac, a well-known French scholar. Lavoisier published his first scientific paper in 1764. From 1763 to 1767, he studied geology with Jean-Étienne Guettard and worked with him on a geological survey of Alsace-Lorraine in 1767. In 1764, he presented a paper to the French Academy of Sciences about the properties of gypsum. In 1766, he received a gold medal from the king for an essay about improving street lighting in cities. In 1768, he was given a provisional position at the Academy of Sciences and worked on creating the first geological map of France.

Lavoisier is best known for his scientific achievements, but he also used his wealth and skills to help improve public life. In 1765, he submitted an essay to the French Academy of Sciences about improving street lighting. In 1768, he planned to build an aqueduct to bring clean water from the Yvette River to Paris. When that project did not start, he focused on purifying water from the Seine River, which led him to study water chemistry and public health. He also studied how gunpowder affected air quality and worked on redesigning the Hôtel-Dieu hospital in 1772 to improve ventilation and air quality.

In the late 1770s, Lavoisier investigated the poor conditions in Parisian prisons and suggested ways to improve them, though his ideas were not widely accepted. He also held competitions to encourage scientific research that could benefit society. Lavoisier believed that public education should be based on scientific knowledge and charity.

Most of Lavoisier’s income came from buying stock in the General Farm, a tax collection company. This allowed him to work on science full-time and support public projects. However, his involvement with the General Farm later harmed his reputation during the French Revolution.

In 1771, when he was 28 years old, Lavoisier married Marie-Anne Pierrette Paulze, the 13-year-old daughter of a senior member of the General Farm. She helped with his scientific work by translating documents, drawing laboratory instruments, and editing his writings. She also hosted gatherings where scientists discussed their research.

A famous painting of Lavoisier and his wife was created by artist Jacques-Louis David in 1788. It was not displayed publicly because of fears it might anger people who opposed the aristocracy.

After joining the General Farm, Lavoisier’s scientific work slowed for a time because he spent much of his time on business. However, he still presented a paper to the Academy of Sciences about an experiment showing that sediment in boiled water came from the glass container, not from the water itself. He also tried to improve France’s tax and money systems to help farmers.

The General Farm controlled tobacco production and sales in France, earning 30 million livres a year in taxes. However, smuggling and mixing tobacco with ash and water reduced these earnings. Lavoisier developed a method to test for ash in tobacco using acid, which caused a strong reaction.

Contributions to chemistry

Lavoisier had a different idea than most people thought at the time. He believed that common air, or one of its parts, combined with substances when they burned. He proved this through experiments.

In late 1772, Lavoisier studied combustion, which would become his most important scientific work. He shared his findings with the Academy in a note on October 20, explaining that when phosphorus burned, it combined with a large amount of air to form a substance called acid spirit of phosphorus. He also noted that the phosphorus gained weight after burning. In another note on November 1, he expanded his findings to sulfur, suggesting that the same process might occur with other substances that gain weight when burned or calcined. He believed the weight increase in metals was caused by the same reason.

In 1773, Lavoisier reviewed research on air, especially "fixed air," and repeated experiments by other scientists. He published his findings in a book called Opuscules physiques et chimiques in 1774. During this work, he studied Joseph Black’s research on chalk and quicklime. Black showed that chalk contained a substance now known as carbon dioxide, which was different from common air. Lavoisier realized that this "fixed air" was the same gas released when metals were reduced with charcoal. He suggested that the air combining with metals during calcination might be Black’s fixed air, or carbon dioxide.

In spring 1774, Lavoisier tested the calcination of tin and lead in sealed containers. His results showed that the weight increase in metals during combustion was due to combining with air. However, he still needed to determine whether this was common air or only a part of it. In October 1774, Joseph Priestley visited Paris and told Lavoisier about a gas he produced by heating mercury calx with a burning glass. This gas supported combustion very strongly. Priestley thought it was a pure form of common air, but he was unsure of its exact nature. Lavoisier studied the gas and concluded in a report read to the Academy in 1775 that it was a pure form of common air. He showed that mercury calx could be reduced with charcoal, releasing Black’s fixed air. When reduced without charcoal, it released a gas that supported respiration and combustion more effectively. He concluded that this gas was pure common air.

After returning to England, Priestley tested the gas again and found it was not just pure air but much better for respiration and combustion. He called it "dephlogisticated air," thinking it was common air without phlogiston. He believed this gas could absorb more phlogiston from burning materials and living things, explaining why combustion and breathing were easier in this gas.

Lavoisier conducted some of the first chemical experiments that measured reactants and products carefully. He sealed reactions in glass containers to prevent gas loss, which was a major step in chemistry. In 1774, he showed that even though matter changes form during a chemical reaction, the total mass stays the same. For example, burning wood to ashes keeps the total mass unchanged if all gases are included. His experiments supported the law of conservation of mass, which states that matter is neither created nor destroyed, only transformed. In France, this law is called Lavoisier’s Law, based on his book Traité Élémentaire de Chimie, which says, "Nothing is lost, nothing is created, everything is transformed." Earlier scientists like Mikhail Lomonosov, Jean Rey, Joseph Black, and Henry Cavendish had similar ideas, but Lavoisier’s work was the first widely accepted proof.

In 1787, Lavoisier and others proposed a new system for naming chemical substances to the Academy. At the time, there was no clear way to name chemicals. Their work, Méthode de nomenclature chimique, tied the new system to Lavoisier’s oxygen theory of chemistry.

The old idea of earth, air, fire, and water as elements was replaced. Instead, 33 substances that could not be broken down further were listed as elements. These included light, caloric (heat), oxygen, hydrogen, nitrogen, carbon, sulfur, phosphorus, and others. The names of acids were based on the elements they contained and their oxygen levels. For example, sulfuric acid has more oxygen than sulfurous acid. Salts from "ic" acids ended with "ate," like copper sulfate, while salts from "ous" acids ended with "ite," like copper sulfite.

The new system changed how chemicals were named. For example, "copper sulfate" replaced the old term "vitriol of Venus." Lavoisier’s naming system spread across Europe and the United States, becoming standard in chemistry. This marked the start of the anti-phlogistic approach to chemistry.

Lavoisier is often seen as a key figure in the chemical revolution. His precise measurements and detailed records helped prove the law of conservation of mass. His new chemical terms, inspired by Linnaeus’s binomial system, also marked major changes in the field.

Notable works

The formal version of Lavoisier's Easter Memoir was published in 1778. Between the time it was first written and its publication, Lavoisier had time to repeat some of Priestley's recent experiments and conduct new ones. He studied Priestley's dephlogisticated air and also examined the air left after metals were calcined. He found that this leftover air did not support burning or breathing. He showed that mixing five parts of this air with one part of dephlogisticated air created common atmospheric air. This meant that common air was a mixture of two different chemical substances with unique properties. When the revised Easter Memoir was published in 1778, Lavoisier no longer said that the substance combining with metals during calcination was common air. Instead, he called it "the healthiest and purest part of the air" or "the eminently respirable part of the air." That same year, he named this substance "oxygen," derived from Greek words meaning "acid former." He noticed that burning nonmetals like sulfur, phosphorus, charcoal, and nitrogen produced acidic substances. He believed all acids contained oxygen, making oxygen the acidifying element.

Between 1772 and 1778, Lavoisier focused on developing a new theory of combustion. In 1783, he presented a paper titled Réflexions sur le phlogistique (Reflections on Phlogiston) to the academy, which strongly criticized the phlogiston theory of combustion. That year, he also began experiments on the composition of water, which became a key part of his combustion theory and helped many scientists accept his ideas. Researchers had been testing mixtures of hydrogen (called "inflammable air") and "dephlogisticated air" (now known as oxygen) by using electric sparks. All observed that burning hydrogen in oxygen produced pure water, but they interpreted the reaction differently within the phlogiston framework. Lavoisier learned of Cavendish's experiment in June 1783 through Charles Blagden (before the results were published in 1784) and quickly recognized water as the oxide of a "hydrogenerative" gas.

Working with Laplace, Lavoisier created water by burning hydrogen and oxygen in a bell jar over mercury. His precise measurements supported the idea that water was not an element, as previously believed, but a compound of two gases: hydrogen and oxygen. This explained the production of inflammable air when metals dissolved in acids (hydrogen from water breaking down) and the reduction of calces by inflammable air (gas from calx combining with oxygen to form water).

Despite these findings, many chemists still rejected Lavoisier's antiphlogistic approach. He worked to prove water's composition, using experiments to support his theory. With Jean-Baptiste Meusnier, he passed water through a red-hot iron gun barrel, allowing oxygen to combine with iron and hydrogen to exit. He reported his results to eight decimal places to the Académie des Sciences in April 1784. Some opponents claimed his experiments showed phlogiston was displaced from iron by water combining with the metal. Lavoisier created a new apparatus using a pneumatic trough, balances, a thermometer, and a barometer, all carefully calibrated. Thirty scientists observed the decomposition and synthesis of water with this setup, convincing many of the accuracy of his theories. However, the experiment's details were not fully explained, and the paper ended with a brief statement that the results "more than sufficiently proved" water's composition. It also claimed the methods used would unite chemistry with other sciences and advance discoveries.

Lavoisier used his new naming system in his Traité élémentaire de chimie (Elementary Treatise on Chemistry), published in 1789. This work summarized his contributions to chemistry and is considered the first modern chemistry textbook. It centered on the oxygen theory, presented the law of conservation of mass, and rejected the phlogiston theory. It defined an element as a substance that could not be broken down by known chemical methods and described how chemical compounds form from elements. The book became a classic in science history. Though many chemists resisted his ideas, demand for the Traité élémentaire in Edinburgh led to its translation into English within a year of its French publication. Regardless, the work was strong enough to influence the next generation of scientists.

The connection between combustion and respiration had long been noted because air played a role in both. Lavoisier was therefore required to expand his combustion theory to include respiration. His first papers on this topic were read to the Academy of Sciences in 1777, but his most important work was done in 1782–1783 with Laplace. Their findings were published in a memoir titled On Heat. Lavoisier and Laplace designed an ice calorimeter to measure heat released during combustion or respiration. The calorimeter's outer shell was filled with snow, which melted to keep the inner shell at 0°C. By measuring carbon dioxide and heat produced when a guinea pig was confined in the device, and comparing it to the heat from burning carbon to produce the same amount of carbon dioxide, they concluded that respiration was a slow combustion process. Lavoisier stated, "la respiration est donc une combustion," meaning respiratory gas exchange is a type of burning, like a candle.

This slow combustion in the lungs allowed animals to maintain body heat above their surroundings,

Legacy

Lavoisier made important contributions to chemistry by deliberately working to connect all his experiments to one scientific theory. He regularly used a chemical balance, used oxygen to disprove the phlogiston theory, and created a new system for naming chemical substances. His system stated that oxygen was a necessary part of all acids, although this was later found to be incorrect.

Lavoisier also worked with Laplace on early studies in physical chemistry and thermodynamics. They used a calorimeter to measure the amount of heat produced for each unit of carbon dioxide released. Their experiments showed that both flames and animals released the same amount of heat, suggesting that animals generate energy through a type of burning process.

Lavoisier helped develop early ideas about chemical composition and changes. He proposed the radical theory, which suggested that certain groups of atoms act as a single unit during chemical reactions and combine with oxygen. He also discovered that diamond is a crystalline form of carbon, introducing the idea that elements can exist in different forms.

He designed a gasometer, a costly tool used in his demonstrations. Although he used it only for these purposes, he also created smaller, less expensive versions that were accurate enough for other chemists to use.

His work is seen as the most significant in helping chemistry reach the same level of understanding as physics and mathematics in the 18th century.

After his death, many of his scientific writings and instruments were collected by his family and placed at the Château de la Canière in Puy-de-Dôme.

Mount Lavoisier in New Zealand's Paparoa Range was named in his honor in 1970 by the Department of Scientific and Industrial Research.

In popular culture

In the Breaking Bad season 5 episode "Say My Name" (episode 7), Walter White says to Todd Alquist, "I don’t need you to be Antoine Lavoisier." This means Todd does not need to be an expert to help with making methamphetamine.

Awards and honours

During his lifetime, Lavoisier received a gold medal from the King of France for his work on urban street lighting in 1766. He was also appointed to the French Academy of Sciences in 1768 and elected as a member of the American Philosophical Society in 1775.

In 1999, Lavoisier’s contributions were recognized as an International Historic Chemical Landmark by the American Chemical Society, the Académie des sciences de L'institut de France, and the Société Chimique de France. In 2015, his 1788 publication, Méthode de Nomenclature Chimique, co-authored with Louis-Bernard Guyton de Morveau, Claude Louis Berthollet, and Antoine François, comte de Fourcroy, was honored with a Citation for Chemical Breakthrough Award by the Division of History of Chemistry of the American Chemical Society. The award ceremony took place at the Académie des Sciences in Paris.

Several medals named after Lavoisier have been created by organizations such as the Société chimique de France, the International Society for Biological Calorimetry, and the DuPont company. He is also remembered through the Franklin-Lavoisier Prize, which celebrates the friendship between Antoine-Laurent Lavoisier and Benjamin Franklin. This prize, which includes a medal, is awarded jointly by the Fondation de la Maison de la Chimie in Paris, France, and the Science History Institute in Philadelphia, PA, USA.

Selected writings

• Physical and Chemical Essays (Paris: Chez Durand, Didot, Esprit, 1774). (Second edition, 1801)
• The Art of Manufacturing Alkali Salts and Potash, Published by Order of the King, by the General Managers of Gunpowder and Saltpeter (Paris, 1779).
• Instruction on Methods to Compensate for Fodder Shortages and Increase Animal Feed, Supplement to the Instruction on Methods to Address Fodder Shortages, Published by Order of the King on May 31, 1785.
• (with Guyton de Morveau, Claude-Louis Berthollet, Antoine Fourcroy) Chemical Nomenclature Method (Paris: Chez Cuchet, 1787)
• (with Fourcroy, Morveau, Cadet, Baumé, d'Arcet, and Sage) Chemical Nomenclature, or Ancient and Modern Synonyms, to Aid in Understanding Authors (Paris: Chez Cuchet, 1789)
• Elementary Treatise on Chemistry, Presented in a New Order and Based on Modern Discoveries (Paris: Chez Cuchet, 1789; Brussels: Cultures et Civilisations, 1965)
• (with Pierre-Simon Laplace) "Memoir on Heat," Memoirs of the Academy of Sciences (1780), pages 355–408.
• Memoir Containing Experiments on Heat Conducted During the Winter of 1783–1784, by P.S. de Laplace and A. K. Lavoisier (1792)
• Memoirs of Physics and Chemistry, from the Arcueil Society (1805: published after death)

• Essays Physical and Chemical (London: for Joseph Johnson, 1776; London: Frank Cass and Company Ltd., 1970) translation by Thomas Henry of Physical and Chemical Essays
• The Art of Manufacturing Alkaline Salts and Potash, Published by Order of His Most Christian Majesty, and Approved by the Royal Academy of Sciences (1784) translated by Charles Williamos of The Art of Manufacturing Alkali Salts and Potash
• (with Pierre-Simon Laplace) Memoir on Heat: Read to the Royal Academy of Sciences, June 28, 1783, by Messrs. Lavoisier and De La Place of the Same Academy (New York: Neale Watson Academic Publications, 1982) translated by Henry Guerlac of Memoir on Heat
• Essays on the Effects of Various Processes on Atmospheric Air; With a Particular Focus on the Constitution of Acids, translated by Thomas Henry (London: Warrington, 1783) includes these essays:

• "Experiments on Animal Respiration and the Changes in Air Passing Through Their Lungs" (Read to the Académie des Sciences, May 3, 1777)
• "On the Combustion of Candles in Atmospheric Air and in Dephlogistated Air" (Communicated to the Académie des Sciences, 1777)
• "On the Combustion of Kunckel's Phosphorus"
• "On the Existence of Air in Nitrous Acid and the Means to Decompose and Recompose That Acid"
• "On the Solution of Mercury in Vitriolic Acid"
• "Experiments on the Combustion of Alum with Phlogistic Substances and the Changes in Air Where Pyrophorus Was Burned"
• "On the Vitriolisation of Martial Pyrites"
• "General Considerations on the Nature of Acids and the Principles They Are Composed Of"
• "On the Combination of the Matter of Fire with Evaporable Fluids and the Formation of Elastic Aëriform Fluids"

• "Reflections on Phlogiston," translated by Nicholas W. Best of "Réflexions sur le phlogistique, pour servir de suite à la théorie de la combustion et de la calcination" (Read to the Académie Royale des Sciences over two nights, June 28 and July 13, 1783). Published in two parts:

• Best, Nicholas W. (2015). "Lavoisier's 'Reflections on Phlogiston' I: Against Phlogiston Theory." Foundations of Chemistry. 17 (2): 361–378. doi: 10.1007/s10698-015-9220-5. S2CID 170422925.
• Best, Nicholas W. (2016). "Lavoisier's 'Reflections on Phlogiston' II: On the Nature of Heat." Foundations of Chemistry. 18 (1): 3–13. doi: 10.1007/s10698-015-9236-x. S2CID 94677080.

• Method of Chemical Nomenclature: Proposed by Messrs. De Moreau, Lavoisier, Bertholet, and De Fourcroy (1788) Dictionary
• Elements of Chemistry, in a New Systematic Order, Containing All the Modern Discoveries (Edinburgh: William Creech, 1790; New York: Dover, 1965) translated by Robert Kerr of Elementary Treatise on Chemistry. ISBN 978-0-486-64624-4 (Dover). 1799 edition, 1802 edition: Volume 1, Volume 2. Some illustrations from the 1793 edition. Additional illustrations from the Science History Institute. More illustrations (from Collected Works) from the Science History Institute.

• 1790 copy of "Elements of Chemistry in a Systematic Order Containing All the Modern Discoveries"
• Title page to "Elements of Chemistry in a Systematic Order Containing All the Modern Discoveries" (1790)
• Preface to "Elements of Chemistry in a Systematic Order Containing All the Modern Discoveries" (1790)
• First page of "Elements of Chemistry in a Systematic Order Containing All the Modern Discoveries" (1790)