Antoine Laurent de Lavoisier

Antoine Lavoisier

Antoine Laurent de Lavoisier [ lavwaˈzje ] (born August 26, 1743 in Paris ; † May 8, 1794 ibid) was a French chemist and scientist, lawyer , principal tenant , economist and head of the French powder administration. He introduced quantitative measuring methods into chemistry , recognized the role of oxygen in combustion and thus refuted the then prevailing phlogiston theory . Lavoisier created many of the foundations of modern chemistry. He is considered the founder and father of the first chemical revolution. Despite his high academic reputation and his commitment to reforms, his role in the Ancien Régime made him a victim of the reign of terror during the French Revolution .

Live and act

Lavoisier and his wife Marie , Jacques-Louis David (1788), Metropolitan Museum of Art

origin

His ancestors came from Villers-Cotterêts , a small town in a large wooded area north of Paris; they rose from the peasant class (one of his ancestors was a postmaster in the city in the 17th century). Antoine Laurent de Lavoisier was the eldest son of the doctor and lawyer Jean Antoine Lavoisier (1715-1775) and his wife Émilie Punctis (approx. 1729-1748), who was the daughter of a lawyer. While still a law student in Paris in 1741, his father inherited the post of lawyer at the Parlement , the highest court in Paris, from his uncle Waroquier . His parents married on May 28, 1742 and lived in Paris on Cul-de-sac Pecquet (quartier des Blancs-Manteaux) in their uncle's old house. His sister, two years younger than him, was Marie Marguerite Émilie Lavoisier (1745-1760). After the mother's early death, the family with the half-orphans moved to the house of their maternal grandmother, Madame Punctis, on Rue de Four St. Eustache. Lavoisier lived there until his marriage in 1771. His aunt Constance Punctis took his mother's place in upbringing. Lavoisier's father bought a post in 1775, which gave him a hereditary title of nobility and which Lavoisier inherited on his death.

Studies, geology and first experiments

Lavoisier was interested in the natural sciences from a young age. From 1754 he attended the Collège Mazarin (Collège des Quatre Nations) as a day pupil, where, in addition to a thorough classical education (he won prizes for Greek and Latin translations), he also enjoyed the best education in natural sciences and mathematics possible in Paris at the time. He attended lectures by the chemist Guillaume-François Rouelle (1703–1770), the experimental physicist Jean-Antoine Nollet (1700–1770), the mathematician Nicolas Louis de Lacaille (1713–1762) and the botanist Bernard de Jussieu (1699–1777), where in particular Lacaille taught and encouraged him in the natural sciences. Instead of the bachelor's degree he started in 1761 at the request of his father with the law degree . In 1764 he received his doctorate in law and was enrolled on the Paris bar list.

At that time he was particularly interested in meteorology (in this area he made observations again and again later), geology, mineralogy, and chemistry. A family friend, Jean-Étienne Guettard (1715–1786), encouraged him early on to occupy himself with geology and mineralogy, and since this also required knowledge of chemistry, including this science. So he attended further lectures at the Jardin du roi with Guillaume-François Rouelle and attended his laboratory courses in his pharmacy. He put on a rock and mineral collection and explored in 1763 the area around his hometown with Guettard. He planned a geological mapping of France, which was approved for him in 1766, and took Lavoisier on his exploratory trips in northern France and Normandy in preparation.

Lavoisier set up a small research laboratory and began the first experiments. At the age of 22 he published his first work, a treatise on gypsum , Analyze du gypse (1765), the first of a planned series of studies on mineral analysis. In contrast to his predecessors, he examined these with wet chemical methods (as observed in nature through the action of water). Gypsum, as found in the pavement of Paris, was after him a neutral salt based on a sulphurous acid and lime that released water when heated (crystal water according to Rouelle). Marggraf had already come to these findings , and Étienne Mignot de Montigny , who examined the work for the academy, had already published it, even if he did not treat it as thoroughly as Lavoisier. He gave a lecture about it before the academy (1765), which published it in 1768 in their Mémoir series, in which mainly non-members published. Even then, he tried to be accepted into the Académie des sciences, initially as an adjoint as the youngest candidate at the time. Initially, however, the older Cadet de Gassicourt was preferred in the chemistry section . Lavoisier saw himself then and later primarily as an experimental physicist, for whom at that time no section existed (it was only set up in 1785 on Lavoisier's initiative) and only in analytical work such as the one on gypsum as a chemist.

In 1764 he took part in the competition with a thorough, exhaustive price publication that the lieutenant general of the Paris police had launched for a work on the best street lighting. Although none won the award, he received a gold medal from the academy on behalf of the king in 1766. With Guettard he made a study trip to the Vosges, Alsace and Lorraine in 1767, as part of the work on a mineralogical-geological atlas of France. Until 1770 he worked with Guettard on a total of 16 regional geological-mineralogical maps (with symbols for rock and mineral deposits) and was connected to the project until 1777 when Antoine Monnet took over. Lavoisier was responsible for barometric altitude measurements, inclination measurements, water and mineral analyzes. Lavoisier also began a research program for a theory of geology, where he went from Rouelle, Guettard and Buffon (Théorie de la terre 1749). Guettard assumed two formations, a crystalline basement (terre ancienne) and the sediment deposit from a sea flood (terre nouvelle). Lavoisier soon recognized in the Terre nouvelle a sequence of several sea advances with alternating deposits of fine and coarse material. The Terre ancienne did not consist of a single layer, but, according to Lavoisier, probably of a sequence of older coastal deposits. His interest in geology did not wane later, but he did not publish his thoughts on it until 1788.

Thanks to support from his family, he did not give up his plans for admission to the academy. In 1768 he published a paper on analysis of water samples that he had made on his travels with Guettard. In addition to mineral water, he also examined drinking water samples, which he considered to be much more socially important. In addition to determining salts after evaporation, he also used a newly developed hydrometer to determine the specific gravity of the samples. In 1768 he was then elected to the Académie des sciences as a chemistry assistant (chimiste-adjoint) . The direct choice fell on the older metallurgist and mining engineer Gabriel Jars , but he was adjoint chimiste surnuméraire with special permission and when Jars died in 1769 he moved to his post.

Barrière des Vertus as part of the wall of the general tenants

Lavoisier and the Ferme générale

In 1768 Lavoisier joined the Ferme générale , the organization of the main customs tenants. The number of these main customs tenants (fermiers) was initially limited to 40, from 1775 to 60 people. The contractor, i.e. the fermier, undertakes to pay a rent to the treasury and in return received a surplus from the customs revenue, for example for the trade in salt and tobacco and the import of goods into Paris. Tariffs were levied not only at the external borders, but also between the provinces in the country, where there were significant price differences, for example for salt. Smuggling flourished and the tax collectors had their own armed officials who fought it and had the right to search anyone's property and property. The penalties for smuggling salt were draconian (galley) and the tax farmers were hated by the common people. For the lease from around 1768 to 1774, the farm had to pay 90 million livres per annum . Thus a tenant had to advance 2.25 million livres. In order to be able to present such high sums , several people hid behind a ferme , who were referred to as assistants. Lavoisier was initially an assistant to Fermier François Baudon (* 1686).

Lavoisier's first activities in the Ferme générale consisted of inspection trips; so he stayed in Picardy for about a few months in 1768 . The next year he was busy checking the tobacco factories and customs offices in northern France. His supervisor was his future father-in-law, and the reports were addressed to him. In 1779 he became a full member of the Ferme. From 1780, half of its profits were transferred to the state by Finance Minister Jacques Necker , and the farm's interest claims for its advanced capital were limited.

After becoming head of the Paris customs in 1782, Lavoisier was the initiator of the construction of the Wall of the Tenants General (Mur des Fermiers généraux), which began in 1785 , the purpose of which was to prevent smuggling when the import tax was levied on goods to Paris. Paris hadn't had a wall since the 16th century and the building, for which land was expropriated, aroused much displeasure. A 1787 pamphlet picked up Lavoisier's work on breathing and said it would suffocate the city in its own bad air. Over the years of his activity as a member of the corporation of tax tenants Ferme générale , Lavoisier was able to acquire a large fortune, from which he used considerable sums to finance his research. He also pushed through some reforms, such as the abolition of the anti-Semitic hoof tax (Droit de pied fourchu) of 30 pieces of silver for Jews traveling through Clermontoise (the same tax was levied on pigs). Jews therefore avoided the district and the economy suffered.

The Fermiers also had the tobacco monopoly (import, production, sale to dealers) with significant tax revenues (30 million livres per year) and Lavoisier's work in tobacco improvement later played a role in his trial, accused of adulteration of tobacco. But it was mainly the smugglers who, for example, stretched the tobacco with ashes. Lavoisier found a simple way of determining this by adding acid. Lavoisier observed that small amounts of ash improved the taste and he also found that the product quality was improved by small amounts of water, so that 6.3 percent by volume of water was systematically added. But he took this into account in the resale price. Its dense system of controls made it unpopular not only with smugglers, but also with tobacco sellers.

Arsenal of Paris near the Bastille, plan by Turgot. Lavoisier's official residence was in the home of the directors in the Petit Arsenal near the Bastille.

Wedding and laboratory on rue Neuve des Bons Enfants

Lavoisier, then 28 years old, married Marie Anne Pierette Paulze, who was only 13 years old, on December 16, 1771, later Marie Lavoisier (1758–1836). She was the daughter of Jacques Paulze (1723–1794) and Claudine Catherine Thoynet de Rozières. As a general tax collector (main customs leaseholder) in the agricultural sector, Jacques Paulze acted as Lavoisier's superior in the Ferme générale and was one of its most influential members. He was also director of the French East India Company, Directeur de la Compagnie des Indes, and his brother-in-law was Finance Minister Joseph Marie Terray .

The young couple moved into a house on rue Neuve des Bons Enfants (now rue Radziwill), which was surrounded by a garden. This house was a wedding present from Lavoisier's father, who retired to an estate near Paris, in Le Bourget . There, in the rue Neuve des Bons Enfants, and from 1776 in their apartment in the arsenal, it was now possible for the two of them to set up a large laboratory in which his wife, who also enjoyed experimenting under the guidance of Lavoisier, kept the laboratory notebook, among other things ( usually she was present at the experiments). She also translated scientific works from English (Lavoisier's language skills were limited) and was a good draftsman ( David's pupil ) and contributed illustrations, for example for Lavoisier's main work, Traité de la chimie . One of Lavoisier's greatest merits was to precisely note, measure, and weigh everything in his experiments. He had apparatuses and instruments constructed with which gases in particular could be measured and weighed more precisely than before. Later he was able to store larger masses of gas and to weigh gases to an accuracy of 50 milligrams. The methodical three-way division of the representation of chemical experiments, which has been preserved to this day, was also valuable for later natural scientists. He divided the test descriptions into:

1. Experiment ( preparation de l'expérience, today: description of the experiment, materials and methods)
2. Result ( effet, today: test result, results)
3. Reflections ( réflexions, today: conclusions, discussion).

Lavoisier had an extensive correspondence with scholars all over Europe and had a large library with the most important scientific journals. He divided his time strictly and tried, in addition to his other obligations, to be able to experiment up to six hours a day, from 6 to 9 a.m. and 7 to 10 p.m. as well as one day of the week (Saturday) all day (his Jour de bonheur, as his wife wrote in her biographical note), which he was particularly looking forward to and excited about. Guests were often present at the experiments and Lavoisier talked to them about the experiments. The foreign guests included Benjamin Franklin , Arthur Young , Martinus van Marum and James Watt . He also enjoyed working with other scientists. His laboratory in the arsenal, in particular, was one of the best equipped in Europe; in France only Guyton de Morveau's was anywhere near comparable.

The couple enjoyed going to the opera and had their own box. The marriage was harmonious and happy, but they had no children.

Académie des sciences and other societies

Lavoisier had already been accepted into the select circle of scientists of the French Academy , Académie des Sciences , as the youngest full member in 1768 at the age of only 25 . In 1772 he became an associate member and in 1778 a pensionnaire (the highest rank). He regularly took part in the academy's twice-weekly meetings. Later, meetings of various committees of the Academy took place, often under his chairmanship, in his private house, accompanied by experiments and banquets, the good reputation of which his wife ensured. A committee, in which Lavoisier was a member, examined the condition of the prisons and hospitals, another, in which Benjamin Franklin was also a member, examined the animal magnetism of Franz Anton Mesmer .

In 1782 he became a member of the Société royale de médecine , in 1783 in the Société royale d'agriculture and in 1785 in the Comité d'agriculture, where he also lectured on his agricultural experiments. One goal of his efforts was to improve the yields in Sologne, which is known for its poor soils .

Lavoisier, a well-known scientist, was appointed director of the French Academy of Sciences in 1784 . In this function he also had access to the king, among other things it was his job to introduce the members to the king. In 1788 he was elected a member ( Fellow ) of the Royal Society .

Gunpowder Factory Inspector and Businessman

Eleuthère Irénée du Pont (1771–1834) and Antoine Laurent de Lavoisier (1743–1794) in the laboratory

In 1775 he and three other people were appointed by Jacques Turgot (1727–1781) to inspect the gunpowder factories (Comité des Poudres et Salpêtres). In order to create uniform conditions, he wrote a small book with regulations on powder production in 1777, which was reprinted in large numbers during the Revolutionary Wars in 1794, without naming Lavoisier. Lavoisier's increase in the quality of powder production was an important factor in the success of the French armies during the Revolutionary Wars. In his leading role in the state powder administration, he was able to increase production significantly and achieved significant savings in production costs. During this time he also met Eleuthère Irénée du Pont de Nemours (1771–1834). In the old powder mill in Corbeil-Essonnes , which was closed in 1822 , Du Pont worked for Lavoisier as a chemical technician . He also came into friendly contact with Benjamin Franklin , then Paris representative of the rebellious Americans during the War of Independence , and was later in contact with him by letters; the Americans obtained powder from France. Eleuthère Irénée du Pont later set up their powder production in the USA and was the founder of the US chemical dynasty DuPont .

In the arsenal of Paris , an extensive ammunition depot and arms depot on the right bank of the Seine , Lavoisier had an official apartment with a well-equipped laboratory in the so-called Petit Arsenal (Hôtel des Régisseurs) not far from the Bastille from 1776 . As one of the directors (régisseurs) of the Régie de Poudre (powder administration) in the arsenal, Lavoisier received 2,400 livres a year and a small percentage for every pound of powder produced. His fortune increased and in 1778 he bought the Fréchines estate near Blois , which over time grew to 200 hectares. He leased the property he had inherited from his father in 1778. Lavoisier began to deal scientifically with agriculture on his estate, tried to implement many ideas, but his "experiments" were less successful there and he made losses because he stubbornly stuck to them, even though he was the overall production on his estate increased. As a landlord he built a school and after the bad harvest of 1787 he supported the people in Blois and Romorantin , who could no longer pay the grain prices.

Lavoisier belonged to the wealthiest class in France. According to Claude Viel, the chemicals and instruments in his estate were worth 3.8 to 4.3 million francs from 1993, and his experiments on water synthesis alone cost him 10 million francs (in 1993 monetary value). He could not finance this from his salary alone, but only from the income as a general tenant. As a businessman he was a supporter of free trade and the physiocrats , recognized the deficiencies in the system and criticized the exploitation of the peasants in the form of labor, high lease fees and serfdom. When the forerunner of the National Bank, the Caisse d'escompte , was founded by Turgot in 1776, he became one of the directors and played an important role in it.

French Revolution, Execution and Aftermath

Lavoisier was a member of the Assembly of Estates in the province of Orléans, where his estate was located , at the 1787/88 session . He campaigned for reforms in the assembly, but it did not come to any significant resolutions. He also ran for the Estates General convened in 1789 , but was only a substitute member.

At the beginning of the French Revolution he was still in charge of the powder administration and directly involved in events as bank director. He came under pressure as the revolutionary masses suspiciously watched every delivery of powder from the arsenal and was also temporarily arrested in July 1789 until Lafayette and Lavoisier's friend, Mayor Jean-Sylvain Bailly, resolved the situation. Other officials at the time had been hanged from lanterns by the mob on such occasions. He signed up for the vigilante group and was elected to the parish council of Paris, but also immediately felt how unpopular he was (the picture of David of him and his wife had to be removed from an art exhibition for this reason). The tax farmers were not initially deposed because they were dependent on their income, which made them safe (none of them left the country). Lavoisier also saw in a letter to Joseph Black in 1790 that his days in public office were numbered, but still not an immediate threat, but rather an opportunity for more free time, which he wanted to use to travel to England. Lavoisier also continued his research on breathing, collaborating with Armand-Jean-François Seguin , and preparing even larger publications. He was politically active in the moderate but short-lived Club of the Friends of the Constitution, which also included the physiocrat Pierre Samuel du Pont de Nemours, as well as Condorcet and Abbé Sieyes . In September 1790 he was no longer elected to the local council. The academy suffered from a lack of funding, but in 1790 initiated a program for the uniform introduction of measurements ( metric system ) and weights, which was officially approved in 1791 and in whose commission Lavoisier was secretary and treasurer and who he and Laplace until his dismissal belonged to others in December 1793. With Haüy , he was also responsible for determining the density of the water there. In March 1791, the tax farmers' contract was terminated and their task was taken over by the state customs administration, which began a long drawn-out settlement process. Lavoisier tried in vain to become a member of the Customs Committee. In the summer of 1791 he lost his post as one of the directors of the powder administration as part of a restructuring. However, he was allowed to continue living in the apartment and laboratory in the arsenal after his protest. In June 1791 he loaned Pierre Samuel du Pont de Nemours 70,000 livres so that he could buy a printing company that would not only print his magazine, but also works from the academy and thus Lavoisier's own chemical works. This was soon taken over by his son Eleuthère Irénée du Pont. In autumn 1791, in times of financial need, he became treasurer of the academy and partially supported needy colleagues out of his own pocket. In the eyes of the revolutionaries, the academy was an institution of the king and the nobility. In the same year, the National Assembly set up a consultation office for scientific and technical problems, whose chemistry committee Lavoisier belonged and for which he suggested material for paper money as the first task. In 1791 he published a comprehensive report on the financial situation of the state and a study on the situation of agriculture.

From 1791 Lavoisier was exposed to violent and foul attacks on the part of the doctor and revolutionary publicist Jean Paul Marat , whom he had made an enemy in 1780 when he disapproved of his erroneous writing on burning. In 1792 the situation in Paris worsened with the beginning of the Revolutionary War and after the storming of the Tuileries, Lavoisier also left his apartment in the Arsenal and rented a house on Boulevard de la Madeleine. In autumn he had lost all offices and was considering opening a pharmacy. However, he was still involved in matters relating to the Academy, which was finally dissolved after the Jacobins came to power in the summer of 1793. As a member of the Consultation Bureau, he was involved in proposals to reform public education, including the establishment of new elite universities such as the École Polytechnique, which were implemented in late 1793. The revolutionaries also decided to take a closer look at the delayed settlement of the Fermiers' financial management and to speed it up. In this context, Lavoisier's apartment was searched and sealed, which was soon partially repealed so that Lavoisier could continue his commission work.

Trial and Execution

Execution on the Place de la Concorde

As a member of the hated Fermiers généraux , he was imprisoned together with 28 colleagues (former tax farmers) in November 1793, initially on the pretext of speeding up their accounting, for which they were brought from the prison to the former palace of the tax farmers, where the conditions of detention were worse. Her property was confiscated and the Lavoisier estate and house were resealed. At the end of January, the Fermiers submitted their final accounts. At the same time, however, a control commission had been formed which came to the conclusion that the Fermiers had cheated the state out of 130 million livres (rumor has it that considerably higher sums were being discussed beforehand). The reports were discussed in secret in the Finance Committee. In particular, a former tax administration employee who was prosecuted for embezzlement, Antoine Dupin, stood out as a driving force in the prosecution and control of the accounting. On May 5, 1794, the convention decided to hand over the tax tenant case to the Revolutionary Tribunal . Actually, this was not responsible. In the meantime, further charges against Lavoisier himself had been added, such as adulteration of tobacco (addition of water, which increased the weight and thus the price), and in the process (without any proof) money was allocated to enemies of the republic abroad, which resulted in the death penalty . The public prosecutor was not Antoine Quentin Fouquier-Tinville , but Liéndon. They did not receive the indictment until late at night on the evening before the trial and they were only able to confer with the four defense lawyers for 15 minutes on the day of the trial. The public trial was a farce and a show trial , they were unanimously sentenced to death and their property was confiscated. That same Thursday, May 8, 1794, they were guillotined on the Place de la Révolution (now Place de la Concorde ) in the afternoon . The guillotine was an invention of Joseph-Ignace Guillotin , who worked with Lavoisier on a commission of inquiry into mesmerism . Lavoisier is said to have walked up the steps to the guillotine without being noticed. In a farewell letter to a cousin written the night before, he wrote: My life has been reasonably long and happy and: The events I got caught up in will probably save me the inconveniences of old age. I will die indifferently. He was fourth on the scaffold, his father-in-law was beheaded before him and the execution lasted only 35 minutes. The fanatical presiding judge of the Revolutionary Tribunal Jean-Baptiste Coffinhal (1762–1794) is often put in the mouth: La république n'a pas besoin de savants et de chimistes, le cours de la justice ne peut être suspendu. ("The republic needs neither scientists nor chemists. The course of justice must not be stopped.") According to Guerlac, however, history is apocryphal. The biographer Grimaux states that the sources contradict each other in terms of wording, circumstances and author of the quote and that no direct witness statements are known. In his funeral address for Lavoisier in 1795, Fourcroy gave the judge a slightly different wording: La republique n'avant plus besoin de savants, un seul homme d'esprit suffisait à la tete des affaires (The republic does not need scientists, one man of spirit at the head of the state is enough). Since the incident was also taken up in the article about Lavoisier by Georges Cuvier in the biography Michaud , which goes back to unpublished biographical notes of Madame Lavoisier (which in the surviving manuscript only go to 1793), Grimaux nevertheless considered such a statement by the judge to be likely .

Like the others guillotined that day, Lavoisier lies in a mass grave on the Cimetière des Errancis .

After the execution

Lavoisier's friend, the Italian mathematician and astronomer Joseph-Louis Lagrange (1736–1813) summed up bitterly one day after the execution:

«Il ne leur a fallu qu'un moment pour faire tomber cette tête, et cent années peut-être ne suffiront pas pour en reproduire une semblable. »

"It only took you a moment to cut off that head, but a hundred years may not be enough to produce a similar one."

- Joseph-Louis Lagrange

As chairman of the Scientific and Technical Consultation Office, Lagrange had previously issued an opinion in which Lavoisier (who had requested this) was certified to be one of Europe's leading scientists. Jean Noël Hallé brought it to the court on the day of the trial. The Committee for Weights and Measures had also campaigned in vain for him ( René-Just Haüy and Jean-Charles de Borda , who were themselves at risk as clergymen and former nobles) with the argument that Lavoisier's investigations into thermal expansion were essential for their work. Other close collaborators, some of whom were well networked with the revolutionaries or even belonged to the Jacobins ( Morveau , Hassenfratz , Gaspard Monge , Fourcroy), on the other hand, did not make any public statements during the time of terror, which later angered Madame Lavoisier. Fourcroy, however, had apparently pleaded personally with Robespierre on behalf of Lavoisier before the trial and had advanced to a meeting of the public security committee, which Robespierre passed in cold silence, whereupon no one else dared to speak. Claude-Antoine Prieur hurried after Fourcroy and warned him urgently to make further advances if he wanted to keep his head. Grimaux accused Fourcroy of unfair motives in his Lavoisier biography. After Grimaux he was an excellent speaker and populator, but a second-rate chemist, and when he spoke of the victory of French chemists on the triumph of the chemical nomenclature in which he was involved, Lavoisier firmly rejected this and claimed the successes for himself. Morveau later justified himself to the editor of the Annals of Chemistry Lorenz von Crell that he was not in Paris at the time, but tested an aerostatic machine on behalf of the War Ministry in Meudon .

The widow Marie Lavoisier was upset about what she saw as the lack of support for her husband from French scientists and other high-ranking people. From June to August 1794 she was imprisoned herself. After the end of the reign of terror, Lavoisier was rehabilitated like the other tax farmers and the widow Lavoisier, who played a leading role in the campaign to restore the Fermiers' confiscated property, got the confiscated property back. It now turned out that the Fermiers owed the state no money at all, but on the contrary still had claims. Madame Lavoisier also urged Dupin's conviction in 1795 for his defamatory and active role in the prosecution of the Fermiers. Before the trial of the Fermiers, she tried to persuade Dupin to keep her husband out of the indictment, but lost her composure in the process. At a memorial service on August 2, 1795, Lavoisier was solemnly honored in the Lycée des Arts (in the Palais Royal) founded in 1792, which Lavoisier co-founded and whose representatives had the courage to present him with an honor before the trial in prison. Fourcroy made one of the speeches, recalling the time of terror that paralyzed many of his friends and prevented them from standing up for him. The widow wasn't there. In a biographical note about her husband, she wrote: Il fut persecuté par les hommes qu'il avait le plus servi (He was persecuted by the people he had served most).

From 1791 Lavoisier worked on a larger work, the Mémoires de physique et chimie, laid out in five or more volumes , with which he wanted to advance his plan to make chemistry as precise as physics. Printing of the first volume had already started in 1793 when it was interrupted by the closure of the academy. In total, the first two volumes (each around 410 pages) and 40 pages of the fourth volume existed as manuscripts. Marie Lavoisier only had them printed in 1805 and then only distributed privately to selected scholars. They provide significantly new insights into Lavoisier's research in recent years, including revisions of already published works, but were not included in the collected works that appeared from 1862 onwards. Some of the reports collected there are also from Séguin (who offered to write the preface to Marie Lavoisier, which she refused), Fourcroy and his assistant Louis-Nicolas Vauquelin and Louis Charles Henri Macquart , because Lavoisier also took on chemists whose work his system close ones. He also planned a textbook on agronomy and a revision of his Traité de Chimie.

Scientific work

Collection of equipment from Lavoisier's laboratory. Musée des arts et métiers Paris

Lavoisier was a skilful experimenter and his systematic separation of conjectures and speculations into a clearly structured argumentation gave scientific chemistry the tools it needed to make further progress.

One of the main phases of his research began in 1772, the crucial year (Crucial year) according to his biographer Guerlac , in which he began to develop his theory of combustion, which was directed against the phlogiston theory , and which brought it into connection with the oxygen in the air discovered by Joseph Priestley . He substantiated this quantitatively with weighings based on the law of conservation of mass explicitly formulated and highlighted by him for the first time for chemical reactions , developed a theory of acids based on oxygen and clarified the composition of carbon dioxide ( fixed air according to Joseph Black ) and other air components. In addition, he began to investigate breathing, which then occupied him particularly in his last creative phase. Another highlight was his proof, after Henry Cavendish's discovery of hydrogen , that water was not an element, which received a great deal of attention and also completed his preparation for a general attack on the phlogiston theory, which began in 1785. He presented his findings in his textbook in 1789 and published a new, rational chemical nomenclature with colleagues in 1787, which quickly spread internationally. In the last phase he dealt with the research of life processes (respiration, fermentation, metabolism) and quantitative heat theory.

His main work is the two-volume Traité élémentaire de la chimie from 1789, in which he deals in the first volume with his systematics of chemical substances, thermodynamics, analysis of air gases, fermentation, organic analysis and theory of acids, in the second volume with chemical investigation methods and instruments detailed descriptions and illustrations.

Early work

The work on mineralogy and gypsum as well as its water analyzes have already been mentioned above.

In 1770 he published his treatise on the nature of water (Mémoire sur al nature de l'Eau et sur lés Expériences par les quelles on a prétendu prouver la possibilité de son changement en terre), which demonstrated his analytical and experimental skills. Lavoisier wanted to refute the claim made by some chemists that water could be converted to earth. He heated distilled water several times over a period of several months in a closed, gas-free vessel (pelican), found no gain in weight and traced the observed impurities back to the glass envelope through precise weighing.

Lavoisier proved that diamond is made of carbon

In 1772 Lavoisier published a sensational work (Sur la destruction du diamant par le feu) in the Mémoirs of the Academy in which he burned a diamond with a burning glass under an airtight glass hood. It was fixed air (carbon dioxide) and Lavoisier was able to prove that the diamond was pure carbon. He repeated the experiment by varying the atmosphere under the glass hood, but with fixed air and in a vacuum no combustion took place. The first experiments took place in the laboratory of Rouelle in 1771, on a larger scale he carried them out with Pierre Joseph Macquer , Mathurin Brisson and Louis Claude Cadet de Gassicourt . The experiment proved that chemical elements could appear in very different forms ( allotropy ).

Lavoisier (with protective goggles) experiments with his large mobile magnifying glass

The principle of oxidation, role of oxygen and theory of acids

Prehistory and influences on Lavoisier

In experiments on incineration, it was found that typical substances such as wood, coal and paper found that the residue from the incineration was lighter than the initial product. It was concluded that a substance escapes from the original material when it is burned. This substance, although invisible, must have weight . Since this phenomenon was observed in almost every combustion, it was assumed that it must be one and the same substance. Georg Ernst Stahl (1659–1734) gave this substance the name phlogiston . This phlogiston theory was then paradigmatic well into the 18th century . In England, Robert Boyle (1626–1692) also carried out combustion experiments. He stated that the combustion residue (formation of a stone or salt-like substance, calcification ) was heavier than the starting material in some experiments with metals . This was also observed in the 17th century by Jean Rey , Ole Borch and John Mayow ( Tractus de sal-nitro et spiritu nitro-aereo, Oxford 1669), the latter blaming a proportion of the air that he called saltpeter air and also for blamed respiration and the formation of acids. Boyle attributed the weight gain to fire particles that combined with the metal, and the supporters of the phlogiston theory also resorted to these or other ad hoc explanations, for them the burning of metals with weight gain was an exception to the much more frequently observed case of weight loss in coal, wood, and paper. In 1772 a book by Guyton de Morveau was published which showed this increase in weight also when other metals besides lead and tin were burned.

Giambatista Beccaria in Turin (which Lavoisier knew) recognized as early as 1774 the important point that the increase in weight when incinerated in a closed room was dependent on the amount of air . Beccaria influenced Lavoisier, like other chemists in Europe, with his experiments on the effect of electrical discharges on metal limes, which created a connection between phlogiston and electricity (published 1772).

Lavoisier's apparatus for the decomposition of red mercury oxide. The famous phlogiston experiment. Drawing by Marie Lavoisier from the Traité élémentaire de chimie (1789)

Traité élémentaire de chimie (1789)

Stephen Hale's empirical research on the elasticity of air, but also its fixability in solid bodies, was found in the translation of his work Vegetable staticks, or an account of some static experiments on the sap of vegetables. (1727) by Georges-Louis Leclerc de Buffon from 1735 entered the French scholarly world and also influenced Lavoisier. Lavoisier probably knew it from the lectures at Rouelle. Another source for the idea of ​​the fixation of components of air was the anonymously published encyclopedia article by Turgot on the expandability of gases and vapors, which also contained ideas of the phase transformation of substances from solid to liquid to gaseous.

In the 1750s, while heating limestone , Joseph Black discovered carbon dioxide (fixed air) and found it was heavier than air, extinguishing the combustion flame, breathing and killing animals. In addition, dissolved in water, passed through milk of lime, it could in turn precipitate limestone. Much of the findings of Hales and Black were known in France through the translation of Experimental Essays on Medical and Philosophical Subjects (1766) by David Macbride . However, being a medical writer, he mainly dealt with possible uses in medicine.

In 1774, Pierre Bayen published on the release of a gas, which he mistakenly believed to be Joseph Black's fixed air, when red mercury oxide (mercury lime) was heated . This happened without the presence of a phlogiston- rich substance such as coal. Bayen was also able to reverse this with the same gas, increasing the weight. Thereupon he renounced the phlogiston theory. Lavoisier was part of a commission in the autumn of 1774 to investigate this. Priestley also reported on a similar experiment in 1775 and reported the observation of 1774 to Lavoisier and other French scientists during a stay in Paris in October of the same year. A little later he called the gas (oxygen) dephlogized air. Priestley found that the gas made flames brighter. Priestley discovered other gases (he reports about them in his Experiments and Observations on Different Kinds of Air , published from 1774 ) and remained a supporter of the phlogiston theory or an extension he created. Another independent discoverer of oxygen was Carl Wilhelm Scheele in Sweden, but he did not publish it until 1777.

In this context there were quite controversial questions of priority which Lavoisier skilfully avoided. The fact is, however, that he substantiated his findings quantitatively and checked them with many other experiments, where he typically followed an analysis with the inversion in a synthesis.

Experiments by Lavoisier

After Guerlac, 1772 was the decisive year in which Lavoisier began to deal with cremation, after Beretta this happened a lot earlier. In 1766 he became acquainted with the theory of Johann Friedrich Meyer , who attributed the corrosive effect of slaked lime and similar alkaline substances to an acidum pingue (and also the increase in weight when burning metals to metal lime). In the same year he acquired books from Jean Hellot's library , including an annotated edition of Stahl's book on Sulfur, and his experiments probably began then.

Lavoisier observed in 1772 that phosphorus and sulfur increased in weight when they were burned (which produced acids) and thereby absorbed constituents from the air. He wondered whether the previously observed weight increase in metals did not come about in the same way. On November 1st, as is customary for particularly important discoveries, he deposited his observations in a sealed envelope at the Academy of Sciences, in which he wrote:

“About eight days ago I discovered that when sulfur is burned, it does not lose weight, on the contrary, it gains weight. The same thing happens with phosphorus: the weight gain comes from a significant amount of air that is fixed during combustion and that combines with the vapors. This discovery led me to believe that what one observes when sulfur and phosphorus are burned could also occur in all other bodies whose weight increases when burned. "

- Antoine Laurent de Lavoisier

The experiments also convinced him that the air components played a major role in the formation of acids. According to Lavoisier, they were created by burning non-metals.

In February 1773 he began a new laboratory book for a long series of experiments which, according to Lavoisier, would bring about a revolution in physics and chemistry. All elastic fluids that escaped from bodies during various chemical reactions and through the air absorbed during combustion should be examined. To this end, he also undertook a literature search and wanted to repeat all known experiments himself and expand his own. He presented his results to the Academy in 1773 and published a book on this in January 1774 (Opuscules physiques et chimiques). That same year he learned of Bayen and Priestley's observations. He examined the dephlogized air of Priestley (oxygen) and found that it extended the life of birds in locked containers. With carbon it formed fixed air (carbon dioxide), with which he clarified its composition. The remaining air after the combustion of the mercury (mainly nitrogen) caused flames to go out like Black's fixed air (carbon dioxide), but did not produce any precipitation in the lime water.

He also repeated the burning of metals (lead, tin) in closed containers and found that only part of the air (around a fifth) contributed to the increase in weight, which was dependent on the volume of the enclosed air. He also found a mistake in Robert Boyle's earlier attempts. He had claimed to be able to observe an increase in weight in closed vessels, which he attributed to fire particles, but which Lavoisier proved to be a measurement error. He also found that the amount of air (oxygen) absorbed by the metal was heavier than the air and the residual air left over after calcination was lighter. In 1774 he presented his results to the Academy, a first essay (Sur la calcination des metaux dans les vaisseaux fermes et sur la cause de l'augmentation de poids qu'ils acquirent pendant cette operation) appeared in Rozier's Observations sur la physique in 1774 and the essay appeared more fully in the Academy's memoirs in 1777. Even more important was his essay (Memoire sur la nature du principe qui se combine avec les metaux pendant leur calcination, et qui en augmente le poids), which appeared in April 1775 in the journal Observations sur la physique and more fully in 1778 in the Academy's treatises . Since the publications in the Academy's Mémoirs were too slow with years of delay, Lavoisier first published in the Observations. In both cases, however, what was typical for him, he changed the content and updated it to reflect the knowledge he had gained in the meantime. There was no mention of Priestley or Bayen.

In 1776 his essay Sur l'existence de l'air dans l'acide nitreux (On the existence of air in nitric acid) appeared, in which he presented his theory of the role of oxygen in acids. For him, the oxygen was the decisive element that determined the nature of the acids, which most chemists took over (until the discovery of hydrogen chloride by Humphry Davy in 1808). In 1779 he put these findings down in his text Considérations générales sur la nature des acides (General considerations on the nature of acids), which did not appear until 1781. For oxygen, instead of the purest component of air (air pur), vital air (air vital) or very breathable air (air éminemment respirable) , he now used the term oxygen, that is, he spoke of the acid-forming principle as the principle oxigine, from which in his Nomenclature chimique 1787 became oxygène ( acid-forming from the Greek). According to Lavoisier, the strength of the acids was determined by the degree of oxidation, but this led to a number of complications. It started with the fact that, according to his theory, water should actually be an acid, from which Lavoisier helped himself by assigning the lowest oxidation level to the oxygen in it. In 1785 he showed that the dissolution of metals in acids led to similar metal limes as with calcination in air, which he called wet calcination .

During this time he partly worked with the chemist Jean-Baptiste-Michel Bucquet , who, however, died in 1780.

Lavoisier's laboratory in the Musée des arts et métiers

Fight against the phlogiston followers

Lavoisier's chemistry soon became known as anti-inflammatory chemistry (the word comes from Richard Kirwan in 1787). He propagated it in his Reflexions sur la phlogistique of 1786, which his biographer Douglas McKie called one of the most remarkable writings in the history of chemistry in 1935. and Henry Guerlac a brilliant dialectical achievement. He not only dealt with steel, but also with his more modern followers such as Pierre-Joseph Macquer , Priestley or Antoine Baumé (without being able to convince Priestley or Baumé). His most ardent and influential opponent was Jean-Claude Delamétherie , who was the editor of the journal Observation sur la physique and made it the mouthpiece of his opponents, in which Lavoisier had previously published. On his side were the chemists Claude-Louis Berthollet , Antoine de Fourcroy and Guyton de Morveau , with whom he wrote the nomenclature chimique (1787), which became very influential internationally and in which they built their new combustion theory in such a way that Joseph Black complained that with the new chemical nomenclature one is also forced to adopt its theory. The group also published a critically commented translation of the book of Essay on Phlogiston by Richard Kirwan (translation by Marie Lavoisier) in 1788 and founded a new journal, the Annales de Chimie (1789). Finally, Lavoisier propagated his theory in his textbook Traité élémentaire de la chimie from 1789 and Fourcroy in his also very influential textbook Élemens d'histoire naturelle et de chimie from the third edition of 1788 (4th edition 1791, 5th edition 1793). With a few exceptions, the followers of the old doctrine of phlogiston transferred to the new camp one after the other, including Joseph Black, who communicated this to Lavoisier in a letter in 1790, and Kirwan, one of its main representatives. In 1791 he surrendered to Berthollet in a letter to the French chemists, which in turn annoyed Lavoisier, who felt compelled to point out publicly that this was his theory and not that of the French chemists. Lavoisier also used his weight in the academy after becoming president of the Academy of Sciences in 1784, for example with new appointments in the spirit of the anti-inflammatory campaign.

At the beginning of his campaign in the 1780s, he had few followers. The English phlogiston followers gathered around Richard Kirwan. He explained the increase in weight during calcination as follows: Phlogiston escaped when burned, combined with the dephlogized air of Priestley and formed fixed air, which formed the metal lime. Lavoisier's argument that his theory followed directly from precision measurements, the English chemists countered that precision in measurements (a main argument of Lavoisier) does not necessarily imply precision in the conclusions drawn. The constructions of the phlogiston pendants became more and more complicated and the connection of Lavoisier's theory of oxygen with the extremely useful new nomenclature ultimately led to the victory of Lavoisier's followers. Jean-Antoine Chaptal took over Lavoisier's teaching in 1784 and taught it in his courses and Martinus van Marum was one of the first foreign scholars to take over his teaching in 1787. Other chemists like Macquer, Priestley, and Baumé never followed the new chemistry. In Germany, the Traité appeared in a German translation in 1792 (System der Antiphlogistische Chemie) by Sigismund Friedrich Hermbstädt , who also made a name for himself in spreading the nomenclature of the Lavoisier School in German-speaking countries.

To promote the breakthrough of his oxidation theory, Lavoisier put on a stage play in June 1789, which he performed in the Arsenal. The flammable phlogiston appeared on the stage, it was accused of serious crimes by Oxygène. The lawyer, Professor Stahl, defended the phlogiston. Eventually Phlogiston was sentenced to death by fire. Madame Lavoisier was the sacrificial priestess. Lorenz von Crell was present and, as a German, in whose country the phlogiston theory was still predominant, found this surprising and shocking. Justus von Liebig, on the other hand, wrote in the following century: The same spirit which at the end of the last century aroused the insane endeavor in a highly civilized people to destroy the monuments of its fame and its history, to build altars for the goddess of reason and to introduce a new calendar, gave rise to the strange feast in which Madame Lavoisier in the robe of a priestess gave the phlogistic system to the flames on an altar, while solemn music played a requiem. At that time the French chemists united to change all names and designations of chemical processes and chemical compounds that had been in use up to that point; a new nomenclature was introduced which, in the wake of a new system that was completed, forced its acceptance in all countries. Hence the apparent gap between present and past chemistry.

Elements and connections

Lavoisier used the term Substances simples for that which is partly close to today's concept of element. According to Lavoisier, they cannot be further broken down by chemical means, at least according to the current state of knowledge, because the list changed, for example, from his nomenclature chimique to the Traité élémentaire de la chimie, published two years later , because some substances have now been recognized as composed, such as ammonia ( Berthollet). The list in the Traité contained only 33 compared to 55 in the nomenclature simple substances, including light, caloric (calorique, heat substance), oxygen (oxygéne), hydrogen (hydrogène) and nitrogen (azote), which he again highlighted separately as simple substances, which occur in all three realms and can be regarded as elements of the body. In the nomenclature, nitrogen was still missing among these elements . The reason for this emphasis on the five elements was that Lavoisier demanded a wide distribution in nature for it and they took on a role in which remnants of the teaching of the principles (means of transformation) of older alchemy can still be recognized. Lavoisier was never sure about the classification of light, but he knew from the work of Jean Senebier and Jan Ingenhousz that it played an important role in plant physiology. According to Guerlac, perhaps after Berthollet's successful analysis of ammonia, he saw nitrogen as an alkali principle. This was followed by the non-metals ( sulfur (soufre), phosphorus (phosphore), carbon (carbone) and the radicals (acid components) of hydrochloric acid (radical muriatique), hydrofluoric acid (radical fluorique), boric acid (radical borique)) and metals ( Antimony , silver , arsenic , bismuth , cobalt , copper , tin , silver, gold , iron , manganese , mercury , molybdenum , nickel , platinum , lead , tungsten , zinc ). He classifies both groups as oxidizable and acid-forming (non-metals) or attackable by acids (metals). This is followed by the alkaline earths calcium (chalk, chaux), magnesium (magnésie), aluminum (alumine), barite (barite, barium sulfate) and silicon (silice). Today's correspondences are given, as Lavoisier noted, the classification was only provisional and some of the specified metals (except gold, silver) and earths were mixed with oxides or other or even oxides themselves (for example, according to Lavoisier very likely barite, which is in behaved like a metal in some experiments). In the case of silicon (quartz and others) and aluminum (aluminum earth) from the list, Humphry Davy demonstrated this in 1807 using electrochemical methods. Compared to the nomenclature, he had eliminated the alkaline substances potash , soda , ammonia and nineteen organic radicals (like that of acetic acid).

Méthode de Nomenclature Chimique. Paris (1787) by de Morveau , Antoine Lavoisier, Berthollet and de Fourcroy .

In the second order of substances, he classified those in his nomenclature that went into the gaseous state through the action of caloric (heat), and in further orders (three to seven) substances that were formed through the action of oxygen, with several oxidation states difference (a precursor to the concept of valence). Oxygen was of central importance in the system. Lavoisier also originated the different endings of acids and salts, which are still in use today, depending on the oxygen content, such as sulfuric acid (acidic sulfurique), sulphurous acid (acidic sulphureux, with less oxygen), sulphate (salt of sulfuric acid), sulphite (salt of sulphurous acid) .

Lavoisier was fundamentally averse to speculations that could not be verified by the experiment; in a well-known passage in the Discours préliminaire of his Traité of 1789, which he also understood as his contribution to the logic and philosophy of science, he described further hypotheses about the nature of the Elements like the existence of atoms and molecules as metaphysical with a multitude of possibilities that cannot be decided with the current state of science:

“Everything that can be said about the number and nature of the elements is, in my opinion, purely metaphysical: these are unsolvable problems for which there are infinitely many solutions, none of which very likely correspond to nature. So I am content to say that when we use the name elements to mean the simple and indivisible molecules that make up bodies, we probably don't know them. If, on the other hand, we associate the name element or the principles of the body with the idea of ​​the last point up to which we can analyze substances, then all substances that we cannot further break down by whatever means are the elements. While we cannot guarantee that these bodies, which we consider simple, are not themselves composed of two or a much larger number of principles, but since they have not been separated or for which we have no means of separating them, we have to treat them from our point of view like simple bodies and only as composed when experience and observation provide us with evidence. "

- Antoine Laurent de Lavoisier

Chemical nomenclature

The introduction of a rational chemical nomenclature, initiated by Lavoisier and Morveau, with which inorganic compounds could now be designated simply and quickly, was of particular influence. Inorganic substances and acids had very strange names before 1787: Alembrotsalz, Kolkothar, Algarothian powder, Pompholix, zinc flowers, vitrolic acid etc. In many cases the names still came from alchemy and its secret language. The first ideas and suggestions for a new nomenclature came from Guyton de Morveau (Mémoire sur les dénominations chymiques, 1782). In 1787 the 250-page book Nomenclature chimique was published, in which Lavoisier, Mourveau, Claude-Louis Berthollet and Fourcroy presented the new nomenclature within the framework of Lavoisier's theory. Lavoisier, Morveau and colleagues developed a binary notation to explain the salts from their bases and acids. Carl von Linné's biology classification system was also a model . For Lavoisier, the influence of Étienne Bonnot de Condillac and his connection between language and logic also played a role.

In addition to the nomenclature, characters after Jean-Henri Hassenfratz (1755–1827) and Pierre-Auguste Adet (1763–1834) were introduced for the chemical elements. These symbols differed a little from the later element symbols - developed by Jöns Jakob Berzelius (1779–1848) in 1814 and used today.

The discovery of hydrogen and the synthesis of water

Lavoisier's apparatus for the production of hydrogen from water by means of thermolysis

Cavendish considered the discoverer of hydrogen (1766), which he won by the action of acids on metals and combustible air called (inflammable air) and the supporters of the phlogiston as Cavendish itself increasingly identified hydrogen with phlogiston. For Lavoisier, the hydrogen could not come from the metal, as Cavendish assumed, but had to come from the acid, but his attempts to form an acid with hydrogen by combustion failed. When hydrogen was burned in air, there appeared to be no reaction product at all, which was a problem for his theory. Cavendish had learned from experiments by Priestley in 1781 that the combustion of oxygen and hydrogen produced a dew, which Cavendish identified in his own experiments in 1783 with water. However, he did not publish his experiments on water synthesis until 1784 and interpreted them in his own modification of the phlogiston theory. Lavoisier had heard of Cavendish's new experiments in 1783 from Charles Blagden , a close confidante of Cavendish, who was in Paris in 1783 and attended experiments by Lavoisier and Laplace.

Lavoisier carried out the experiments afterwards and carried out his own investigations from 1783 to 1785, again obtained water from the two gases in 1783 and then put forward the thesis:

"The combustion of the two types of air and their conversion to water, part by weight, hardly leaves any doubt that this substance, which was previously regarded as an element, is a compound substance."

- Antoine Laurent de Lavoisier

In doing so, Lavoisier (who, however, had a forerunner in Cavendish) collapsed the ancient buildings of thought still based on Aristotle, which held air and water to be indestructible elements, and at the same time removed the last obstacle to his attack on the phlogiston theory. He substantiated his findings with another experiment (1784 with Meusnier): He heated iron filings to a red heat, ran steam over them and found that the iron had turned into iron oxide and gained weight in the process. He also found that part of the water vapor had condensed back into water, but another part had decomposed into so-called combustible air . Lavoisier realized that he had obtained pure hydrogen ( hydrogène, called water-forming by Lavoisier) in his gas container. He called the gas oxyhydrogen . He presented all of this to the public in spectacular experiments in 1785.

Again, there were disagreements about the priority, as Lavoisier was unclear in his publication that he had been informed by Blagden about Cavendish's experiments before carrying out his own.

Sources for Lavoisier's experiments also include a device invented by Abbé Felice Fontana in 1777, a kind of inverted test tube in a mercury bath. In one experiment, the glass above the mercury contained water and Fontana introduced red-hot charcoal, which generated hydrogen in the test tube. He used the instrument a lot and is shown in the painting by David von Lavoisier and his wife. In 1782 Alessandro Volta demonstrated his electric eudiometer , which he called electric cannon , in Paris Lavoisier . In a closed glass vessel, he used electrical discharges to trigger burns in various gases. He had observed the formation of a moist substance during the reaction between oxygen (dephlogized air) and hydrogen (flammable air) , but was so surprised that he did not think of identifying it with water. But he most likely also showed Lavoisier (Beccara) this attempt. Devices of this type were later also in Lavoisier's laboratory, with which the experiments on water synthesis and analysis were easier to carry out. However, Lavoisier used a large specially made gasometer for his convincing demonstrations in front of an audience . In his experiments Lavoisier was supported in part by the mathematician Gaspard Monge , who had been interested in chemistry since 1777, Jean-Baptiste Meusnier de la Place , who got in touch with Lavoisier through Monge, Fourcroy (1785) and von Laplace.

Law of Conservation of Mass and Organic Analysis

The law of conservation of mass in chemical reactions was a general assumption often made by scientists in the 18th century, but it was also fraught with uncertainties since, for example, according to the phlogiston theory , one also saw a substance in heat that led to changes in the weight of substances could. Edme Mariotte formulated the principle (Essai de logique 1678) and it was basically a sequence of atomistic ideas, but Lavoisier was the first to formulate it explicitly in chemical reactions. Lavoisier was able to prove from the calcification of metals (metal oxidation) by careful weight measurements of the decrease in air or the specific weight of air, furthermore from weight determinations by the decomposition of 100 grains of water into 15 grains of inflammable gas (hydrogen) and 85 grains of living air (oxygen), that there is a conservation of mass in chemical reactions. Only this clear evidence could overturn the phlogiston theory. In 1789 he stated in his Traité (Volume 1, Chapter VIII on Fermentation) the principle of mass conservation:

"Nothing is created in operations, whether artificial or natural, and it can be seen as a principle that in every operation there is an equal quantity of matter before and after the operation."

- Antoine Laurent de Lavoisier

Lavoisier systematically used balance tables of weights in the presentation of his measurement results, as well as later when measuring heat. For him, the accuracy of the theoretical analysis corresponded directly to the accuracy of the experiments and vice versa, or as his follower Jean Baptiste Biot put it: One felt the need to combine accuracy in experiment with rigor of theoretical deduction. He thus became the founder of stoichiometry , chemical mathematics, which was later improved by Jeremias Benjamin Richter by recognizing the mathematical connection in salt formation.

In addition to his work on breathing, he was also a pioneer of organic analysis in his study of the combustion of organic matter and fermentation, which he first reported in his traité. He knew that when plant substances are burned, water and carbon dioxide are produced, but wanted to know the combination of carbon, hydrogen and oxygen in plant substances such as alcohol. First he burned oils, then more volatile substances such as alcohol and ether, with a weight ratio of carbon to hydrogen of 3.6 to 1 for alcohol (close to the correct 4: 1). When it comes to fermentation, like its predecessors, it distinguished alcoholic fermentation, acid-producing fermentation (e.g. producing acetic acid) and putrefaction. He saw the violent movement during alcoholic fermentation as a sign of a violent chemical reaction in the rearrangement of the three basic elements (organic principles) C, H, O. In this context, using the example of fermentation, he also set up the first simple reaction equations in the form: Must = alcohol + carbon dioxide (Mout de raisin = acid carbonique + alkool). However, it was not really quantitatively supported in his Traité and, according to Arthur Harden, was an example of how the genius of a researcher triumphed over experimental data.

Thermal theory, physiology of breathing

The Scot Joseph Black, who introduced the concepts of latent heat , specific heat capacity and methods of measuring them, was a pioneer in this field between 1756 and 1766 , with the practical measurements mainly being carried out by James Watt , who was the first to recognize their importance for applications. Black students in Glasgow continued his work ( William Irvine (1743–1787), Adair Crawford with applications in physiology). Crawford in particular also influenced Lavoisier.

This calorimeter was first used in the winter of 1782/1783 by Antoine Lavoisier and Pierre-Simon Laplace .

Lavoisier proceeded from the existence of a "caloricum" ("caloricum", le calorique ), which he counted among the basic elements, as explained in his nomenclature chimique from 1787 and his Traité élémentaire de la chimie from 1789 . In his Traité élémentaire de chimie of 1789, he called the ability of the chemical body to absorb heat , also the ability of the body to absorb heat (capacité des corps pour contenir la materière de la chaleur). According to Lavoisier, with the help of oxygen (oxygen), heat was also released from the air, which would therefore also be part of the air (gaseous oxygen consisted of caloric and oxygen). Occasionally it was objected that the heat substance was nothing more than the phlogiston theory in a new guise, but in contrast to the phlogiston, the effects could be measured exactly. Lavoisier was never able to provide evidence of the existence of such a thermal fluid, as he himself had to admit in 1785 (but he saw this as a common assumption, which was also made by his opponents of phlogistons). In his traité of 1789, he even stated that the assumption of the real existence of a heat substance was not necessary for his argument, only the existence of some kind of repulsive force that counteracts the chemical affinities that hold the bodies together.

Laplace and Lavoisier began their experiments in 1777 and continued them until 1784, with a focus on the winter of 1782/83 and 1783/84. They first established that there are two predominant views of the nature of heat: that of heat substance, an imponderable fluid distributed everywhere, which could penetrate between the spaces of a body to different degrees and determine its temperature. Lavoisier was inclined to believe this. Laplace, on the other hand, had the idea that heat was created by the movement of the smallest parts (molecules) of the body. They did not want to decide between the two theories, which in their opinion might be both true, since some properties spoke for one theory, others for the other, but rather consider properties that followed from both theories, such as the conservation of the amount of heat, valid in the fluid theory as well as due to the conservation of energy in atomic theory.

Laplace and Lavoisier used the ice calorimeter to measure heat. For example, the heat released when various substances were burned melted a corresponding amount of the ice and was therefore a measure of the heat generated when the respective substance was burned . The calorimeter consisted of a number of nested pots. The test specimen was placed in the innermost pot. Crushed ice was filled into the outer one, on the one hand for insulation, on the other hand the heat given off by the test specimen could be measured via the amount of melt water around the inner container. Laplace and Lavoisier measured first in solids, liquids and solutions, later with a special calorimeter also in gases (heat capacities and amounts of heat in chemical reactions such as combustion, solution, mixture). They also wanted to encourage others to do further research with their methods. With that they created thermochemistry . As a result, until the beginning of the 19th century, adiabatic liquid calorimeters prevailed instead of ice calorimeters ; Ice calorimeters were only used again in a modified form by Robert Bunsen and John Herschel . The experiments of Lavoisier and Laplace are among the few Lavoisier's who have recently been checked with apparatus based on the model of the original, and which also provided fairly good agreement with regard to the accuracy achieved. In their experiments on warmth, Laplace and Lavoisier were supported by the Lavoisier student Philippe Gengembre .

Lavoisier dedicated his last experiments around 1790 to breathing. His wife, pictured on the right, sitting at the desk (she also drew the picture). Armand Seguin served as the test subject.

At one point there is a notable reference to the potential use of caloric measurements in the study of chemical reactions: the balance between the heat which the body's molecules strive to separate can be a very accurate means of comparing these affinities . Affinities are the attractive forces that hold the body together and counteract the repulsive force of heat. As is clear from Lavoisier's posthumous Mémoirs de physique et chimie, Lavoisier also adopted this atomistic view in 1793 at the latest . In addition to a repulsive force between the molecules mediated by the caloric, attractive forces (affinities) also act. If the repulsion predominated, gases were formed, with predominant attraction liquids, whereby he also considered the case of close contact (chemical connection) in mind. He also planned to tackle the field of chemical affinities of substances, which he had avoided until then, since the traditional theory was only qualitative in nature.

Laplace and Lavoisier also gave their heat research a physiological direction. Both determined the amount of carbon dioxide, air fixe (fixed air) that a small animal (guinea pig) exhaled during a certain time. Then they put the animal in the ice calorimeter and measured how much ice melted in the same ten hours while it was there. In addition to the gas quantities, they also compared the heat generation of the animal and compared it with that when burning coal. Lavoisier and Laplace concluded that breathing was the same as burning and that it served to maintain the animals' body heat. That was also an important step towards the chemical explanation of life processes.

Lavoisier first demonstrated the importance of oxygen in breathing and that carbon dioxide is produced in 1776 in experiments with Philibert Trudaine de Montigny . His last experiments in 1790/91, in which he was supported by Armand-Jean-François Seguin , who continued them after his death, were also dedicated to the respiratory processes . A human (Seguin) now served as the test subject. Thereafter, the consumption of oxygen during breathing increased with physical performance, digestion and temperature, and absorption took place in the tubules of the lungs. As early as 1785 he found that not all of the oxygen was converted into carbon dioxide, and he assumed that part of it was converted into water, which he also investigated further with Seguin.

Others and names after Lavoisier

• The Lycée Lavoisier in Paris is named in his honor. Lectures have been held there for the public since 1793 and it was founded on the initiative of Lavoisier. Likewise a street in the 8th arrondissement and there are statues of him at the town hall and in the Cours Napoléon of the Louvre.
• Lavoisier is immortalized by name on the Eiffel Tower . See: The 72 names on the Eiffel Tower .
• He is the only non-German scientist who was honored with a bust in the Deutsches Museum in Munich.
• Lavoisier's laboratory has been reconstructed in the Deutsches Museum. Instruments from Lavoisier's laboratory are on display at the Conservatoire national des arts et métiers in Paris, which was founded on Lavoisier's initiative.
• Carl Djerassi and Roald Hoffmann wrote a play Oxygen about the discovery of oxygen, which premiered in 2001.
• The asteroid (6826) Lavoisier was named after him.
• The Lavoisier Medal of the SCF .
• The lunar crater Lavoisier is named after him.
• The UK Antarctic Place-Names Committee named Lavoisier Island, off the west coast of the Antarctic Peninsula , after him in 1960 .
• The genus Lavoisiera DC. from the family of the black mouth plants (Melastomataceae) is named after him.

Fonts (selection)

• Oeuvres de Lavoisier. 6 volumes, Paris: Imprimerie National 1862 to 1894 (Ed. JB Dumas, Edouard Grimaux), Volume 1  - Internet Archive (Traité élémentaire de chimie), Volume 2  - Internet Archive (Mémoirs de chimie et de physique), Volume 3  - Internet Archive (Mémoirs et rapports sur divers sujets de chimie et de la physique pure), Volume 4  - Internet Archive (Mémoirs et rapports sur divers sujets de chimie et de la physique pure).
• Oeuvres de Lavoisier: Correspondance. Volumes 1-3 (Ed. René Fric), Paris: Albin Michel, Vol. 4 (Ed. Michelle Goupil), Paris: Belin 1986, Volumes 5,6, 7 (Ed. Patrice Beret), Paris: Academie des Sciences, Hermann 1993, 1997, 2012.
• Opuscules physiques et chimiques. Paris 1774 (only the first of several planned volumes was published. Archive.org ).
  • English translation: Essays physical and chemical, 1776. ( archive.org ).
  • German translation in CE Weigel: Lavoisier physical-chemical writings. Greifswald, 1783–1794.
• Réflexions sur le phlogistique, pour servir de développement à la theory de la combustion & de la calcination, published in 1777. Mémoires de l'Académie royale des sciences 1786.
  • English translation by Nicholas W. Best: Lavoisier's "Reflections on phlogiston" I: against phlogiston theory. Foundations of Chemistry, Volume 17, 2015, pp. 137-151, Part 2, Volume 18, 2016, pp. 3-13.
• Méthode de nomenclature chimique, proposée par MM. De Morveau, Lavoisier, Bertholet [sic] & de Fourcroy. On ya joint un nouveau système de caractères chimiques, adaptés à cette nomenclature, par MM. Hassenfratz & Adet. Paris 1787, 2nd edition 1789 ( archive.org , archive.org edition 1789).
  • German translation by Karl von Meidinger: Method of chemical nomenclature for the anti-inflammatory system. Vienna 1793, ( archive.org ), and in an abbreviated form by Christoph Girtanner : Beginnings of anti-inflammatory chemistry. Berlin 1792. Digitized, Bavarian State Library.
• Traité élémentaire de chimie. 2 volumes, Paris 1789, 2nd edition 1793, archive.org volume 1, archive.org volume 2).
  • German edition by Sigismund Friedrich Hermbstädt : System of anti-inflammatory chemistry by Anton Lorenz Lavoisier. Berlin, Stettin 1792. Digitized version of the 2nd edition 1803, part 1, Bavarian State Library.
• Mémoires de chimie. Paris, 2 volumes (designed by Lavoisier in 1792, privately distributed by his widow from 1803, they also contain contributions from other scholars).
  • Printed as Mémoires de physique et de chimie. 2 volumes, Bristol: Thoemmes Continuum, 2004.
• With Pierre Simon Laplace : Mémoir sur la chaleur. Mémoir Acad. Sci., 1780 (first published in 1784), pp. 355-480 (also in Oeuvres Volume 2 and reprint Gauthier-Villars 1920).
  • English translation: Memoir on Heat. (Translator Henry Guerlac), New York: Neale Watson Academic Publications, 1982.
  • German translation: Two treatises on warmth. (from the years 1780/1784), Ed. Isidor Rosenthal, Ostwalds Klassiker, Leipzig 1892, ( archive.org ). The additions Mémoire contenant les expériences faites sur la chaleur pendant l'hiver de 1783 à 1784, par MM. De Laplace et Lavoisier, pour servir de supplément au mémoire sur la chaleur publié en 1780, were taken into account (written 1793, experiments Winter 1783/84), which first appeared in the Mémoires de chimie et physique, edited by Marie Lavoisier, and in the Oeuvres, Volume 2.
• De la richiesse territoriale de la France. (Ed. Jean-Claude Perrot), Paris: Editions du CTHS, 1988.
• Patrice Bret (ed.): Lavoisier et l'encyclopédie méthodique: le manusrit des régisseurs des poudres et salpetres. Florence: Olschki 1997 (manuscripts on powder production, detonation and coal that Lavoisier prepared in 1793 for an encyclopedia and a manual).
• Marcellin Berthelot : La revolution chimique - Lavoisier. Paris 1890 (with excerpts from Lavoisier's laboratory books, archive.org ).
• Mémoire sur al nature de l'Eau et sur lés Expériences par les quelles on a prétendu prouver la possibilité de son changement en terre. Memoirs Acad. Sci. 1770 (Oeuvres, Volume 2).
  • German translation: The water. Ostwald's classics, Leipzig: Academic Publishing Society 1930.
  • Studies on the water. Edited by Peter Buck. With an introduction and biography by Hermann Klie. Franzbecker - Didaktischer Dienst, Bad Salzdetfurth 1983, ISBN 3-88120-050-9 . ( Reprinta Historica Didactica 4 series).

More pictures

• 

  Antoine Laurent de Lavoisier; portrait

• 

  Detail section. Burns caused by focusing the sunlight through optical lenses on a combustible material. An experiment that Lavoisier carried out in the 1770s.

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  Burns from focusing sunlight through optical lenses. Representation of the entire experimental setup.

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  Reaction vessel for the controlled combustion of hydrogen

• 

  Lavoisier statue at the town hall

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  Lavoisier statue by Jacques-Léonard Mallet in the Louvre

• 

  Element symbols at the time of Lavoisier, part 1

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  Element symbols at the time of Lavoisier, part 2

• 

  Lavoisier calorimeter

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  Lavoisier, engraving by JF Bolt

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  Lavoisier in his laboratory during the breathing experiments, diorama

literature

• Bernadette Bensaude-Vincent : Lavoisier: Mémoires d'une revolution. Paris: Flammarion, 1993.
• Enrico Bellone (ed.): Lavoisier: The revolution in chemistry. Spectrum of Science - Biography, 1998.
• Marco Beretta: Imaging a Career in Science. The Iconography of Antoine Laurent Lavoisier. Science History Publications, Canton, MA 2001, ISBN 0-88135-294-2 .
• Marco Beretta (Ed.): Lavoisier in Perspective. Munich, Deutsches Museum 2005.
• Martin Carrier : Antoine L. Lavoisier and the Chemical Revolution. In: Pierre Leich (Ed.): Key fossils of scientific thinking. Königshausen & Neumann, Würzburg 2001, ISBN 3-8260-2121-5 , online (PDF; 245 kB).
• Arthur Donovan: Antoine Lavoisier: Science, Administration, and Revolution. Cambridge University Press, 1993.
• Edouard Grimaux : Lavoisier 1743–1795, d'après sa correspondance, ses manuscrits, ses papiers de famille et d'autres documents inédits. Paris 1888, 1896, 3rd edition 1899, ( archive.org ).
• Henry Guerlac : Lavoisier, Antoine-Laurent . In: Charles Coulston Gillispie (Ed.): Dictionary of Scientific Biography . tape 8 : Jonathan Homer Lane - Pierre Joseph Macquer . Charles Scribner's Sons, New York 1973, p. 66–91 (supplemented in the supplementary volumes (Volume 4) by Marco Beretta, Scribner's 2008).
• Henry Guerlac: Lavoisier — The Crucial Year. The Background and Origin of His First Experiments on Combustion in 1772. Ithaca, NY: Cornell University Press, 1961.
• Henry Guerlac: Antoine-Laurent Lavoisier: Chemist and Revolutionary. Scribner, New York 1975.
• Frederic L. Holmes Lavoisier and the Chemistry of Life: an exploration of scientific creativity. Princeton University Press, 1985, Reprint University of Wisconsin Press, 1987.
• Frederic L. Holmes Antoine Lavoisier - the next crucial year: or, the sources of his quantitative method in chemistry. Princeton University Press, 1997.
• Ursula Klein, Wolfgang Lefèvre: Materials in eighteenth-century science. MIT-Press, Cambridge 2007, ISBN 978-0-262-11306-9 .
• Albert Ladenburg : Lectures on the history of the development of chemistry, from Lavoisier to the present. 4th increased and improved edition. Vieweg, Braunschweig 1907. (Unchanged reprint: Wissenschaftliche Buchgesellschaft, Darmstadt 1974, ISBN 3-534-06011-3 . Archive.org ).
• Douglas McKie : Antoine Lavoisier. Victor Gollancz, London 1935, 1952, ( archive.org ).
• Jean-Pierre Poirier: Lavoisier. University of Pennsylvania Press, 1996.
• Walther Skaupy: Great Processes in World History. The Dubarry and Antoine Laurent Lavoisier before the French Revolutionary Tribunal. Magnus Verlag, Essen, p. 63 ff.
• Madison Smartt Bell: Lavoisier in the Year One: The Birth of a New Science in an Age of Revolution. Atlas Books, Norton 2005.
• Max Speter: Lavoisier. In: Günther Bugge: The book of the great chemists. Volume 1, Verlag Chemie, Weinheim 1984, ISBN 3-527-25021-2 .
• Ferenc Szabadváry : Antoine-Laurent Lavoisier. Teubner, Leipzig 1987.
• E. Ashworth Underwood: Lavoisier and the history of respiration. In: Proceedings of the Royal Society of Medicine. Volume 37, 1943, pp. 247-262. PMC 2180993 (free full text).

Web links

Commons : Antoine-Laurent de Lavoisier  - Album with pictures, videos and audio files

Wikisource: Antoine Laurent de Lavoisier  - Sources and full texts (French)

Wikisource: Antoine Laurent de Lavoisier  - Sources and full texts

• Literature by and about Antoine Laurent de Lavoisier in the catalog of the German National Library
• Short biography and references to digital sources in full text in the Virtual Laboratory of the Max Planck Institute for the History of Science (English).
• Walter Jansen: Lavoisier's scientific biography at the University of Oldenburg (PDF; 596 kB).
• Jean-Pierre Poirier (Comité Lavoisier, Académie des Sciences de Paris): Les amis de Lavoisier.

References and comments

1. ^ Georg Korn: Joseph-Ignace Guillotin (1738-1814). A contribution to the history of medicine and the medical status. 1891, p. 23.
2. ^ The Chemical Revolution of Antoine-Laurent Lavoisier. International Historic Chemical Landmark at the Académie des Sciences in Paris 1999, American Chemical Society.
3. ↑ Lavoisier's genealogical tables are reproduced in:
   Grimaux: Lavoisier. 1895, p. 326.
4. ↑ Christian Warolin: Lavoisier at-il de l'enseignement de l'beneficie apothicaire, Guillaume François Rouelle? In: Revue d'histoire de la pharmacie. Volume 83, No. 307, 1995, pp. 361-367, doi: 10.3406 / pharm . 1995.4257 (French).
5. ^ Guerlac: Dictionary of Scientific Biography. Volume 8, p. 70.
6. ↑ Ferenc Szabadváry: Antoine Laurent Lavoisier. The researcher and his time 1743–1794. Joint edition of the Akadémiai Kiadó, Budapest and the Wissenschaftlichen Verlagsgesellschaft, Stuttgart 1973, p. 28 ff.
7. ↑ To F. Baudon.
8. ↑ McKie: Lavoisier. P. 43.
9. ^ WR Aykroyd: Three Philosophers: Lavoisier, Priestley and Cavendish. London 1935, p. 89.
10. ↑ On Lavoisier's reform of tobacco production, the introduction of rigorous quality control and supervision of the tobacco trade, see:
    Arthur Donovan: Antoine Lavoisier. Cambridge UP 1993, p. 123 ff.
11. ^ Church wedding. The marriage contract was signed on December 4th.
    Grimaux: Lavoisier. 1895, p. 40.
12. ^ Genealogy of the Marie Lavoisier family in:
    Grimaux: Lavoisier. 1895, p. 330.
13. ↑ Szabadvary: Lavoisier. Teubner, 1987, p. 12.
14. ↑ 50 milligrams roughly corresponded to the smallest unit of weight grains ( gran ). Lavoisier gives the weights in the following dimensions: pounds (livres), ounces ( once, one pound corresponds to 16 ounces), gros (one ounce corresponds to 8 gros) and grains (one gros corresponds to 8 grains).
15. ^ ^{A b} Max Speter: Lavoisier. In: Günther Bugge: The book of the great chemists. Volume I, Verlag Chemie, Weinheim 1974, ISBN 3-527-25021-2 , p. 304.
16. ^ Claude Viel: Le salon et le laboratoire de Lavoisier à l'Arsenal, cénacle où s'élabora la nouvelle chimie . In: Revue d'histoire de la pharmacie . tape 83 , no. 306 , 1995, pp. 255 , doi : 10.3406 / pharm. 1995.4478 (French, free full text).
17. ↑ Szabadvary: Lavoisier. P. 14. The information follows Madame Lavoisier.
    Guerlac: Dict. Sci. Biogr. P. 84.
18. ^ Claude Viel: Le salon et le laboratoire de Lavoisier à l'Arsenal, cénacle où s'élabora la nouvelle chimie . In: Revue d'histoire de la pharmacie . tape 83 , no. 306 , 1995, pp. 263 , doi : 10.3406 / pharm. 1995.4478 (French, free full text).
19. ^ Entry on Lavoisier, Antoine Laurent (1743–1794) in the Archives of the Royal Society , London
20. ↑ Patrice Bret: Lavoisier à la régie des poudres: Le savant, le financier, l'administrateur et le pédagogue. General Secretary of the Lavoisier Committee of the Académie des Sciences. Text about its administrative importance in French ( PDF; 565 kB ).
21. ↑ Jaime Wisniak: The History of Saltpeter Production with a bit of Pyrotechnics and Lavoisier. In: Chem. Educator. Volume 5, No. 4, 2000, pp. 205-209, doi: 10.1007 / s008970000401a .
22. ^ Claude Viel: Le salon et le laboratoire de Lavoisier à l'Arsenal, cénacle où s'élabora la nouvelle chimie . In: Revue d'histoire de la pharmacie . tape 83 , no. 306 , 1995, pp. 255–266 , doi : 10.3406 / pharm. 1995.4478 (French, free full text).
23. ↑ Szabadvary: Lavoisier. 1987, p. 17.
24. ↑ McKie: Lavoisier. P. 42.
25. ^ Claude Viel: Le salon et le laboratoire de Lavoisier à l'Arsenal, cénacle où s'élabora la nouvelle chimie . In: Revue d'histoire de la pharmacie . tape 83 , no. 306 , 1995, pp. 263 , doi : 10.3406 / pharm. 1995.4478 (French, free full text).
26. ↑ The water synthesis experiments cost him around 50,000 livres, with 1 livre being worth around 200 francs.
27. ↑ As a member of the academy, he earned 2000 to 5000 livres annually, from the powder administration he received 17,000 livres, from the general lease 145,000 livres, i.e. around 29 million francs.
28. ^ Charles Coulston Gillispie : Science and Polity in France. Princeton UP, 2004, p. 322.
29. ^ Georg Korn: Joseph-Ignace Guillotin (1738-1814). A contribution to the history of medicine and the medical status. 1891, p. 23.
30. ↑ Szabadvary: Lavoisier. P. 66. With a reprint of the suicide note written the night before the judgment.
31. ^ Gillespie: Science and Polity in France. P. 323.
32. ↑ Grimaux: Lavoisier. 1895, p. 376.
33. ^ Henri Guerlac: Article Lavoisier. In: Dictionary of Scientific Biography. Volume 8, p. 85. There, J. Guillaume Un mot légéndaire: La république n'a pas besoin de savants, Révolution francais, Volume 38, 1900, pp. 385-399 and Études revolutionnaires, Series 1, Paris 1908, Pp. 136–155.
34. ↑ Grimoux: Lavoisier. 1895, Appendix VIII, p. 376 ff.
35. ^ Lagrange, quoted by Jean Baptiste Joseph Delambre: Notices sur la vie et les ouvrages de M. Le Comte J.-L. Lagrange. In: Delambre (ed.): Oeuvres de Lagrange. Volume 1, Gauthier-Villars 1867, p. XL. He then told Delambre the day after the execution.
36. ↑ McKee: Lavoisier. 1935, p. 299.
37. ↑ Grimaux: Lavoisier. P. 334. In the correspondence from Madame Lavoisier there is no letter from Hassenfratz, Fourcroy or Mourveau with whom she broke off contact because they had not stood up for her husband. Since, for example, Fourcroy also spoke at the memorial service in 1795, she stayed away.
38. ^ Madison Smartt Bell: Lavoisier in the Year One. Atlas Books, Norton, 2005, p. 182.
39. ↑ The scene with Robespierre is also mentioned in Arthur Donavan, Antoine Lavoisier: Science, Administration and Revolution, pp. 295 f. Georges Cuvier wrote in his memoirs that Fourcroy himself was in danger at this time and his options for action were restricted and the scene with Robespierre is contained in a note on Fourcroy by Cuvier (Fonds Cuvier), which refers to the testimony of his cousin André Laugier, According to Gillespie: Science and Polity in France: The End of the Old Regime, Princeton UP 2004, p. 324 f., Fourcroy campaigned for threatened scientists, so he saved Jean d'Arcet, who had been denounced for connections to the Duke of Orléans (Darcet) before the terror. Grimaux: Lavoisier. P. 311.
40. ↑ Grimaux: Lavoisier. P. 310.
41. ^ Gillispie: Science and Polity in France. 2004, p. 324.
42. ^ P. Lemay: La pompe funèbre de Lavoisier au lycée des Arts. In: Revue d'Histoire de la Pharmacie. 1958, pp. 230-236, digitized.
43. ^ Charles Gillispie: Notice biographique de Lavoisier par Madame Lavoisier. Revue d'histoire des sciences, Volume 9, 1956, pp. 52-61, here p. 61, digitized.
44. ↑ Marco Beretta: Article Lavoisier. In: New Dictionary of Scientific Biography . Volume 4, 2008, p. 217.
45. ↑ Szabadvary: Lavoisier. P. 25.
46. ^ Henry Guerlac: Lavoisier: The Crucial Year. The background and Origin of his first experiments on combustion in 1772. Ithaka, New York 1961. Guerlac: Article Lavoisier. In: Dictionary Scientific Biography. Volume 8, p. 72.
47. ↑ Marco Beretta: Lavoisier as a reader of chemical literature. In: Revue d'histoire des sciences. Volume 48, No. 48-1-2, 1995, pp. 71-94, doi: 10.3406 / rhs.1995.1222 .
48. ↑ Szabadvary: Lavoisier. P. 32.
49. ↑ Marco Beretta: Article Lavoisier. In: New Dictionary of Scientific Biography . Volume 4, 2008, p. 214.
50. ↑ That too had been observed before, as Lavoisier himself noted, in this case the Paris pharmacist Pierre Mitouard, known to Lavoisier, and Andreas Sigismund Marggraf .
51. ↑ Lavoisier: Détails historique sur la cause de augmentation de poids. Oeuvres, Volume 2, Paris 1862, p. 103.
52. ↑ Kirwan: Essay on Phlogiston. London 177, p. 7, ( archive.org ).
53. ↑ McKie: Lavoisier. 1935, p. 220.
54. ↑ The idea for this came from his colleague Adet in 1787 (they were disappointed about the reception of the nomenclature chimique in France) and in order to get the printing permission quickly, they pretended to want to publish a translation of the Annals of Chemistry by Lorenz von Crell . Lavoisier was not initially directly involved, but soon played a leading role in the magazine, as did his colleagues Berthollet and Morveau. The first edition appeared in 1789. Beccara: Article Lavoisier. In: New Dictionary of Scientific Biography. Volume 4, 2008, p. 216.
55. ↑ Szabadvary: Lavoisier. P. 44. After Grimaux: Lavoisier. On p. 310 Lavoisier replied in this sense to a statement by Fourcroy about the victory of the French chemists.
56. ^ Jan V. Golinski: The nicety of experiment: Precision of measurement and precision of reasoning in late eighteenth-century chemistry. In: M. Norton Wise (Ed.): The Values ​​of Precision. Princeton UP 1995, pp. 75 f.
57. ↑ Lorenz von Crell published a letter about it in the Chemischen Annalen, Volume 1, 1789, p. 519. Quoted in Karl Hufbauer: The Formation of the German Chemical Community (1720-1795). University of California Press, 1982, p. 96.
58. ^ Justus von Liebig: Chemical letters. Volume 1, Wintersche Verlagshandlung, Leipzig, Heidelberg, 4th edition, 1859, p. 46 f. (Third letter, first in 1844). Before that, Liebig emphasized that chemistry was one of the oldest sciences, contrary to the impression of many of his contemporaries that it was a young science.
59. ^ List of substances by Lavoisier and colleagues in the nomenclature chimique, after an English translation edited by Lyman Spalding in Hanover, New Hampshire 1799.
60. ↑ List of simple substances in the Traité 1789 in the Internet Database of Periodic Tables.
61. ↑ According to Linnaeus' name, these were the three kingdoms of minerals, plants and animals.
62. ^ Henry Guerlac: Article Lavoisier. In: Dictionary of Scientific Biography. Volume 8, p. 82. Based on a note by Lavoisier from 1792.
63. ↑ Guerlac: Dict. Sci. Biogr. Volume 8, p. 82.
64. ↑ The list of elements is for example in Lavoisier: Traité. Volume 1, 1793, p. 192.
65. ^ Lavoisier: Traité. Volume 1, 1793, p. 172 ff.
66. ^ Lavoisier: Traité de la chimie. Volume 1, 1789, p. XVII. Original: Tout ce qu'on peut dire sur le nombre & sur la nature des élémens se borne suivant moi à des discussions purement métaphysiques: ce sont des probèmes indéterminés qu'on se propose de résoudre, qui sont susceptibles d'une infinité de solutions , mais dont il est très-probable qu'aucune en particulier n'est d'accord avec la nature. Je me contenterai donc de dire que si par le nom d'élémens, nous entendons désigner les molécules simples & indivisibles qui composent les corps, il est probable que nous ne les connoissons pas: que si au contraire nous attachons au nom d'élémens ou de principes des corps l'idée du dernier terme auquel parvient l'analyse, toutes les substances que nous n'avons encore pu décomposer par aucun moyen, sont pour nous des élémens; non pas que nous puissions assurer que ces corps que nous regardons comme simples, ne soient pas eux-mêmes composés de deux ou même d'un plus grand nombre de principes, mais puisque ces principes ne se séparent jamais, ou plutôt puisque nous n ' avons aucun moyen de les séparer, ils agissent à notre égard à la manière des corps simples, & nous ne devons les supposer composés qu'au moment où l'expérience & l'observation nous en auront fourni la preuve.
67. ↑ Michaela Hörmann: The expansion of chemistry terminology in France in the 18th century. Hamburg 1997 (diploma thesis Berlin 1995). P. 41.
68. ↑ Szabadvary: Lavoisier. P. 36.
69. ↑ Martin Carrier: Cavendish's version of Phlogistonchemie or: On the empirical success of inaccurate theoretical approaches. In: J. Mittelstraß: Chemistry and the humanities. Akademie Verlag, Berlin 1992, pp. 35-52, online.
70. ↑ Beccara: Article Lavoisier. In: New Dictionary of Scientific Biography. Volume 4, 2008, p. 215.
71. ^ Claude Viel: Le salon et le laboratoire de Lavoisier à l'Arsenal, cénacle où s'élabora la nouvelle chimie . In: Revue d'histoire de la pharmacie . tape 83 , no. 306 , 1995, pp. 259 , doi : 10.3406 / pharm. 1995.4478 (French, free full text).
72. ^ Guerlac: Lavoisier. In: Dict. Sci. Biogr. P. 82, footnote 41.
73. ↑ Christoph Girtanner: Beginnings of anti-inflammatory chemistry . 3. Edition. JF Unger, Berlin 1801, p. 606 , urn : nbn: de: bvb: 12-bsb10072661-1 .
74. ^ Lavoisier: Traité de la chimie. Paris 1801, p. 140 f. Car rien ne se crée, ni dans les opérations de l'art, ni dans celles de la nature, et l'on peut poser en principes que dans touts opération, il ya une égale quantité de matière avant et après l'opération.
75. ^ Biot, quoted from Jan Golinski: The nicety of experiment: Precision of measurement and precision of reasoning in late eighteenth-century chemistry. In: M. Norton Wise (Ed.): The Values ​​of Precision. Princeton UP 1995, p. 75.
76. ↑ Szabadvary: Lavoisier. Teubner, p. 22.
77. ^ Lavoisier: Traité de la chimie. Volume 1, 1802, p. 141.
78. ↑ Quoted from Guerlac: Dict. Sci. Biogr. Volume 8, p. 83.
79. ^ David Fenby: Heat, its measurement from Galileo to Lavoisier. In: Pure & Applied Chemistry. Vol. 59, 1987, doi: 10.1351 / pac198759010091 , pp. 91-100.
80. ^ Robert Morris: Lavoisier and the Caloric Theory. In: British Journal for the History of Science. Volume 6, 1972, p. 31. It refers to a passage in Lavoisiers Sur la phlogistique from 1783.
81. ^ Lavoisier: Traité. Volume 1, 1801, pp. 5-6.
82. ^ Laplace, Lavoisier: Treatise on warmth. Ostwald's classics, p. 6 f.
83. ↑ Beretta: Lavoisier. In: New Dictionary of Scientific Biography. Volume 4, 2008, p. 215 f.
84. ^ Laplace, Lavoisier: Treatise on warmth. Ostwalds Klassiker, p. 39. The passage probably comes from Laplace. According to Morris, British J. History Science, Volume 6, 1972, p. 31, there are many indications that Lavoisier was increasingly arguing at this time with molecular models and forces between them.
85. ↑ Marco Beretta: Article Lavoisier. In: New Dictionary of Scientific Biography . Volume 4, 2008, p. 217.
86. ↑ There is a fragment of a manuscript from 1768 with a sketch of an atomistic structure of matter, which he only took up again in the Mémoires of 1793, which he had left behind.
87. ^ Eva Königsmann: Antoine Lavoisier in the hall of honor of the Deutsches Museum. In: Welt.de. September 13, 2003, accessed December 24, 2014 . 
88. ↑ The chemistry laboratory from the 18th century called "Lavoisier Laboratory". Retrieved December 24, 2014 . 
89. ^ Richard Zare: Oxygen - chemistry in the theater.
90. ↑ Lotte Burkhardt: Directory of eponymous plant names. A collection of eponymic, biographical and bibliographical information on honors in the plant world. Extended Edition. In: BGBM.org. Botanical Garden and Botanical Museum Berlin, Free University Berlin, Berlin 2018.
91. ↑ For this work, Guerlac received the 1958 Pfizer Award from the History of Science Society (HSS) founded by George Sarton and Lawrence Joseph Henderson .