Background

Antoine-Laurent Lavoisier was born into a privileged family on August 26, 1743, in France’s capital city, Paris.

His father was Jean-Antoine Lavoisier, a lawyer in the Paris Parliament.

His mother was Émilie Punctis, whose family wealth had come from a butchery business. She died when Antoine was five years old, leaving him a large amount of money.

Education

Between the ages of 11 and 18, Antoine was educated at Collège des Quatre-Nations, a college of the University of Paris. He studied general subjects there, including the sciences in his final two years.

Although he was very attracted to the sciences, he enrolled in the college’s law school at age 18, aiming to pursue the same career as his father. His father had encouraged him to believe that science was merely a hobby, not a serious profession.

After two years of studying law, Antoine Lavoisier was awarded a bachelor’s degree. A year later, in 1764, he obtained a license to practice as a lawyer but decided against this.

Career

While studying for his law degree Lavoisier maintained his interest in science, attending science lectures in addition to law lectures. In 1764, the year he obtained his license to practice law, he also published his first scientific paper. In the same year, he read a paper to the elite French Academy of Sciences.

In 1765 Lavoisier published a paper on how to improve the street lighting of a large city like Paris. For this paper he received a Gold Medal from the Royal Academy of Sciences in 1766. He was elected to the French Academy of Sciences in 1769, aged just 26.

In 1772 Lavoisier and other chemists bought a diamond and placed it in a closed glass jar. They used a remarkable giant magnifying glass to focus the sun’s rays on the diamond. The diamond burned and disappeared. Lavoisier noted the overall weight of the jar was unchanged, even though all of the diamond had disappeared. This observation would later be part of the evidence convincing him that his law of mass conservation was correct.

Whether diamond or charcoal was burned by the giant lens, the same gas was produced – carbon dioxide. Lavoisier realized that diamond and charcoal are different forms of the same element. He gave this element the name carbon.

In 1772 people did not understand the process of burning. They had inconsistent and confused theories, chief of which was the theory of phlogiston, an undetectable substance that sometimes had negative mass. In 1772, however, when Lavoisier began working in this field, oxygen’s discovery by Joseph Priestley that combustion happens when substances react with oxygen at high temperatures still lay two years in the future. Lavoisier’s work enjoyed a great advantage over many other scientists, namely his great passion for making accurate measurements. He pursued quantitative rather than qualitative science.

That same year Lavoisier discovered that when phosphorus or sulfur are burned in air the products are acidic. The products also weigh more than the original phosphorus or sulfur, suggesting the elements combine with something in the air to produce acids.

In 1774 Joseph Priestley visited Paris. He told Lavoisier about the gas produced when he decomposed the compound we now called mercury oxide. This gas supported combustion much more powerfully than normal air. Priestley believed the gas was a particularly pure version of air. He started calling it dephlogisticated air, believing its unusual properties were caused by the absence of phlogiston. Lavoisier did not believe it was dephlogisticated anything, because he did not believe in phlogiston.

In 1777 Lavoisier correctly identified sulfur as an element. He had carried out extensive experiments involving this substance and observed that it could not be broken down into any simpler substances.

In 1778 Lavoisier found that when mercury oxide is heated its weight decreases. The oxygen gas it releases has exactly the same weight as the weight lost by the mercury oxide. After carrying out work with a number of different substances, and recalling earlier work such as his work in 1772 with carbon, Lavoisier announced a new fundamental law of nature - the law of conservation of mass: matter is conserved in chemical reactions or the total mass of a chemical reaction’s products is identical to the total mass of the starting materials.

In 1779 Lavoisier coined the name oxygen for the element released by mercury oxide. He found oxygen made up 20 percent of air and was vital for combustion and respiration. He also concluded that when phosphorus or sulfur are burned in air, the products are formed by the reaction of these elements with oxygen.

Lavoisier suspected that combustion and respiration are chemically the same. He demonstrated this with the help of Pierre-Simon Laplace. The pair measured the amount of carbon dioxide and heat given off by a guinea pig as it breathed. They compared this to the amount of heat produced when they burned carbon to produce the same amount of carbon dioxide as had been exhaled by the guinea pig. The results allowed Lavoisier to conclude that respiration is a form of combustion. The heat produced by mammals during respiration keeps their bodies above room temperature.

In 1783 Lavoisier coined the name "hydrogen" for the gas which Henry Cavendish had recognized as a new element in 1766; Cavendish had called the gas inflammable air.

Working again with Pierre-Simon Laplace, Lavoisier burned hydrogen with oxygen and found that water was produced, establishing that water is not an element, but is actually a compound made from the elements hydrogen and oxygen. This result astonished many people, because at that time "everyone knew" that water was itself one of the "indivisible" elements. Hydrogen means water former in Greek.

Lavoisier’s work with oxygen and his demonstration of mass conservation had made it absolutely clear to him that phlogiston was fictitious. In 1783 his paper Reflections on Phlogiston marked the beginning of the end for phlogiston and a triumph for Lavoisier's oxygen theory and quantitative chemistry.

In 1789 Lavoisier published his groundbreaking Elementary Treatise on Chemistry. Aristotle's elements of earth, water, air, fire, and quintessence had been abandoned by medieval alchemists, and Lavoisier now abandoned their tria prima of sulfur, mercury, and salt.

Elementary Treatise on Chemistry detailed his oxygen theory of chemistry (banishing phlogiston), made clear the difference between a compound and an element, and contained a list of chemical elements. The list included oxygen, nitrogen, hydrogen, sulfur, phosphorus, carbon, antimony, cobalt, copper, gold, iron, manganese, molybdenum, nickel, platinum, silver, tin, tungsten, and zinc.

Starting in 1791, Lavoisier served on the committee of the French Academy of Sciences which developed the metric system of measurement. Other members of the committee included the well-known mathematicians Pierre-Simon Laplace and Adrien-Marie Legendre.

In addition to his scientific research, Lavoisier was industrious in other fields. At the age of 26, he bought into a company that gathered tax for the French government, Ferme générale. Having done this, he tried to reform tax law to help poorer taxpayers. He also served on the government’s gunpowder commission, improving the quality of French gunpowder considerably.

During the French Revolution, which began in 1789, wealthy people and anyone who had worked for the government were under threat. In 1793 the revolutionaries put an end to the French Academy of Sciences and other academic societies.

In 1794 Lavoisier was branded a traitor because of his involvement with taxation. He was also unpopular with revolutionaries because he had supported foreign scientists whom the revolutionaries wished to strip of their assets.

Lavoisier was sentenced to death by the revolutionaries. Trumped-up charges against him included stealing money from France's Treasury and giving it to France's enemies. Antoine Lavoisier died by the guillotine at the age of 50 on May 8, 1794, in Paris.

Achievements

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  Antoine Lavoisier was a famous chemist and scientist who published a new nomenclature for chemistry, gave oxygen its name, discovered the composition of water, clarified oxygen's role in combustion and oxidation, explored the mechanisms of acid formation and water decomposition, and established a metric system of weights and measures.
  
  Lavoisier was a member of the French Academy of Sciences. In 1766 he received a Gold Medal from the Royal Academy of Sciences.
  
  There is a crater on the Moon named for Lavoisier. In 1989, the asteroid 6826 Lavoisier was discovered.

Works

More photos

• book

  • Elements of Chemistry, In a New Systematic Order, Containing all the Modern Discoveries 1789
  • Essays Physical and Chemical 1776
  • Oeuvres De Lavoisier 1986
  • Essays on the Effects Produced by Various Processes on Atmospheric Air: With a Particular View to an Investigation of the Constitution of the Acids 1783

Religion

Antoine Lavoisier was a Catholic.

Raised in a pious family that had given many priests to the Church, he had held to his beliefs. To Edward King, an English author who had sent him a controversial work, he wrote, "You have done a noble thing in upholding revelation and the authenticity of the Holy Scripture, and it is remarkable that you are using for the defence precisely the same weapons which were once used for the attack."

Politics

A political and social liberal, Lavoisier took an active part in the events leading to the French Revolution, and in its early years he drew up plans and reports advocating many reforms, including the establishment of the metric system of weights and measures.

Views

Antoine Lavoisier was the architect of the chemical revolution. Lavoisier believed that weight was conserved through the course of chemical reactions - even those involving gases. He explained combustion (and respiration) in terms of chemical reactions that involve a component of air which he called oxygen. His venue for the chemical revolution came in 1775, when he was appointed Commissioner of the Royal Gunpowder and Saltpeter Administration. As such, he was able to build a fine laboratory at the Paris Arsenal and make important connections to the scientific community of all of Europe.

In 1774, Lavoisier was repeating Robert Boyle's tin calx experiments from the previous century. Boyle knew the tin gained weight as the calx was formed. The doctrine of Phlogiston explained that phlogiston was released upon calx formation. While modern scientists recognize the implication that this: phlogiston must have a negative weight, early phlogistonists (Becker, Stahl) were not bothered as they considered phlogiston to be something of a philosophical concept. Later phlogistonists such as Priestley did consider phlogiston to be a material substance (Cavendish believed it to be his inflammable air, now H2) but because the theory explained so many chemical phenomena, they were able to overlook its shortcomings. But not Lavoisier.

Lavoisier heated tin in air in a closed vessel. The tin increased in mass upon forming the calx (now SnO) and air rushed into the vessel as it was opened. At about the same time, in October 1774 Priestley visited Paris and met with Lavoisier and told him at a dinner party of his discovery of dephlogisticated air. By coincidence, Lavoisier also received a letter from Scheele (dated September 30, 1774) asking him to repeat one of his experiments that produced oxygen. In November 1774, Lavoisier repeated Priestley's experiment.

By this time Lavoisier was an affirmed anti-phlogistonist. In 1777, Lavoisier conducted an experiment that established a fatal shortcoming of the phlogiston theory. He heated mercury and air using a bell-jar for 12 days. Red mercury calx (now HgO) formed and the volume of air decreased from 50 to 42 in3. The remaining air was determined to be atmospheric mofette, and later renamed azote (now nitrogen). The red (HgO) was heated in a retort producing 8 in3 of dephlogisticated air (O2). The sequence of experiments established that heat caused formation of a calx (the doctrine of phlogiston explained phlogiston was released): Hg(l) + O2(g) → HgO(s).

And then stronger heating reverted the calx back to the original substances which the doctrine of phlogiston would predict to be impossible: HgO(s) → Hg(l) + O2(g).

Proof of the validity of Lavoisier's Oxygen Theory came when Lavoisier (a) decomposed water into two gases, which he named hydrogen and oxygen, and then reformed them into water as had been previously done by Priestley (1781) and then quantitatively by Cavendish.

To spread his ideas and the Oxygen Theory, Lavoisier published "Traité élémentaire de chemie" in 1789. In his book, Lavoisier named a total of 33 elements, most of which are still in use today. It has been said that the book would be recognizable to a student of chemistry as is reads "like a rather old edition of a modern textbook."

Antoine-Laurent Lavoisier discovered no new substances. He made a few new improvements to laboratory methods. Yet he will be remembered to the end of time as the father of modern chemistry. He took the works of others, most notably that of Priestley, Black, Cavendish, and Scheele, and explained it.

Curiously, and consistent with chemistry's infancy, Lavoisier included light as one of the chemical elements. He also included a substance called caloric like phlogiston, to be fictitious. In fact, so much of Elementary Treatise on Chemistry involves caloric in explanations that it slightly spoils the work. Again though, chemistry was still in its infancy, and Lavoisier was largely responsible for pulling it up on to firmer ground.

Quotations: "In nature nothing is created, nothing is lost, everything changes."

"We must trust to nothing but facts: These are presented to us by Nature, and cannot deceive. We ought, in every instance, to submit our reasoning to the test of experiment, and never to search for truth but by the natural road of experiment and observation."

"Life is a chemical process."

"The human mind adjusts itself to a certain point of view, and those who have regarded nature from one angle, during a portion of their life, can adopt new ideas only with difficulty."

Membership

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  French Academy of Sciences

  1769

Personality

Some people say that Lavoisier had an annoying tendency to use other people's results without acknowledgment and draw conclusions of his own.

Quotes from others about the person

• Joseph-Louis Lagrange: "A moment was all that was necessary in which to strike off this head, and probably a hundred years will not be sufficient to produce another like it."
  
  Justus Liebig: "He discovered no new body, no new property, no natural phenomenon previously unknown; but all the facts established by him were the necessary consequences of the labors of those who preceded him. His merit, his immortal glory, consists in this - that he infused into the body of the science a new spirit; but all the members of that body were already in existence, and rightly joined together."

Interests

• reading

Connections

In 1771, Lavoisier married Marie-Anne Paulze (1758-1836). She was 14 at the time of her marriage with Lavoisier.

Her father was a colleague of Lavoisier in the Farmers General. Marie Paulze's mother was a niece of Abbe Terray, France's Controller-General of Finances and one of the most influential men of the French kingdom.

Lavoisier's marriage with Marie Paulze proved to be very successful. She was a skilled artist, engraver, and painter. She kept laboratory records and made sketches of her husband's experiments. She learned English and Latin. She translated the new chemical treatises from England, which included the works of Priestley and Cavendish.

Father:

Jean-Antoine Lavoisier

Mother:

Émilie Punctis

Wife:

Marie-Anne Paulze Lavoisier

friend, colleague:

Pierre-Simon Laplace

Pierre-Simon Laplace and Antoine Lavoisier carried out together several experiments. The two also designed an ice calorimeter to measure the heat released during various chemical reactions.

colleague:

Joseph Priestley

References

• Eureka!: 50 Scientists Who Shaped Human History
  2016
• The Chemist Who Lost His Head: The Story of Antoine Laurent Lavoisier
  1982
• Lavoisier in the Year One: The Birth of a New Science in an Age of Revolution
  2005