Lavoisier, Antoine Laurent

Lavoisier, Antoine Laurent (1743-94): French Chemist.

Universally recognized as the father of modern chemistry, Antoine Laurent Lavoisier stands out as one of the foremost “renaissance men” of the Enlightenment, contributing brilliantly not only to chemistry but to physiology, geology, agronomy, economics, public health hygiene, and the philosophy of civic administration.

Lavoisier, the son of a prominent attorney, was born in Paris on 26 August 1743. His mother died when he was five, whereupon he was raised primarily by an aunt. As a young student he showed talent for mathematics, astronomy, biology, and geology, but favored chemistry. To please his father, Lavoisier obtained a law degree and passed his bar exam, but he still chose to become a chemist rather than practice law. It has been widely speculated, however, that his legal background influenced his desire to organize systematically the laws of chemistry, a science then lacking precision in its procedures and nomenclature.

In the eighteenth century, chemists still had little notion of which substances were elements. Furthermore, their studies were inhibited by belief in some nonexistent elements, most notably the one known as “phlogiston,” a term coined by the chemist Stahl, Georg Ernst. It was thought that combustion was a function of phlogiston interacting with air and other substances. Rejecting theory, Lavoisier created purely quantitative experiments -- the first substantial quantitative experiments in the history of chemistry -- to show what really occurs in the process of combustion. Using, most notably, the burning of metallic substances as his example, he revealed a number of revolutionary facts. He demonstrated, first of all, that air is made up primarily of oxygen and nitrogen, and that the metallic substance, in turning into an acidic product through burning, has simply combined with the oxygen in the air. Weighing the metallic substance and the oxygen in the surrounding air before and after the burning, he noted that the resulting gain in the weight of the metal was precisely equal to the weight of the oxygen lost from the air. Furthermore, the metal showed no loss of mass from any supposed transfer of phlogiston to the atmosphere. Thus, the existence of phlogiston was debunked.

Having demonstrating that mass remains constant before and after a chemical reaction, Lavoisier -- a lifelong professional fiscal expert -- was able to apply the concept of the balance sheet to chemical equations. Thus he established the principle of conservation of mass. This concept, which totally upset prevailing notions, became one of the foundations of modern chemistry.

To these fundamental findings, Lavoisier added the discovery that the human respiratory system is a process of slow combustion whereby the body utilizes oxygen for energy. Lavoisier also went on to coin the term “oxygen,” although the element itself had been previously identified by Priestly.

Assisted by his wife, a highly intelligent member of his research team who kept scrupulous notes of all his experiments, Lavoisier went about determining which substances are elements and which are compounds. Although he was not 100% correct in his assessments, Lavoisier’s list of elements in his seminal text Traité élémentaire de chimie (Elementary Treatise on Chemistry, 1789) served as a solid basis for the modern table of elements.

Lavoisier also wrote the landmark book Méthode de nomenclature chimique (Method of Chemical Nomenclature, 1787) which set up the system, still used today, for naming chemicals according to their physical composition.

Throughout his adult life, Lavoisier served on numerous commissions and government agencies designed to promote science and improve the general well-being of the public. In 1775, he became head of the government gunpowder commission and rather bravely set up his experimental laboratory in a powder mill where he brought together many leading scientists. He was named head of the French Science Academy in 1785, and joined the government committee on Agriculture the same year. As part of other committee work, he helped to establish the metric system and establish accurate systems of weights and measures. He was also appointed Treasury Commissioner in 1791.

Lavoisier tried to put into practical effect the Enlightenment philosophy that government should help the common poor folk become prosperous and healthy through improvements in agriculture and industry. Although his sympathies were with the downtrodden and his ideas were somewhat revolutionary, Lavoisier found himself under attack during the French Revolution. From as early as 1768, when he was appointed Farmer-general of taxes, Lavoisier had financed his scientific pursuits largely through salary earned by serving as a tax collector. That caused him to be hated by many peasants and revolutionaries. In 1794, during the Terror, he was arrested along with numerous associates and formally accused of harming public health by watering down the public’s supply of tobacco. On 8 May 1794, he was, in a matter of hours, tried, convicted, sentenced, and executed, a victim of the guillotine at the age of 51. Madame Lavoisier recouped some of his equipment and documents, facilitating posthumous publication of his Mémoires de chimie (Chemistry Memoirs) in 1805.

Lavoisier is remembered as a giant of the Enlightenment, not only for his many great discoveries but also for his role in advancing the development of basic scientific method, especially in the realm of quantitative experimentation. Although professing a belief in divine revelation regarding scriptural matters, Lavoisier insisted on the use of observation and logic for gaining knowledge of the physical world. He also has come to symbolize the scientific genius misunderstood by many of his contemporaries and victimized by political fanaticism.

Further Reading:

Arthur Donovan, Antoine Lavoisier: Science, Administration and Revolution, 1996.

Douglas McKie, Antoine Lavoisier, 1990.

Lisa Yount, Antoine Lavoisier: Founder of Modern Chemistry, 1997.

Dianna Rivers