[lah vwah ZYAY] was born into a wealthy family in Paris, France, on August 26, 1743. He attended the Collège Mazarin from 1754 to 1761, studying chemistry, botany, astronomy, and mathematics. His first chemical publication appeared in 1764. In 1766 he was awarded a gold medal by the French Academy of Sciences for work on a new improved system of street lighting, and was subsequently elected one of their youngest members.
Although he had inherited a large fortune when his mother died, Lavoisier had to earn a living to support his scientific research, and in 1768 he took an administrative appointment in the Ferme générale, a private agency engaged by the French government to collect taxes.
In 1771, Lavoisier married Marie-Anne Pierette Paulze, the 13-year-old daughter of one of the owners of the Ferme. Marie came to be a very important scientific colleague to her husband, translating documents from English for him, creating sketches and engravings of his laboratory instruments, and editing and publishing his memoirs.
Left: Portrait of Monsieur Lavoisier and His Wife, by Jacques-Louis David.
Right: Drawing by Marie showing some of the apparatus her husband used in his hydrogen combustion experiments.
Beginning in 1775, Lavoisier served in the Royal Gunpowder Association, where his work led to a new method for preparing saltpeter, which in turn led to improvements in the production of gunpowder.
Some of Lavoisier's most important experiments examined the nature of combustion. For many years scientists had believed that all materials contained a mysterious substance called phlogiston. The process of burning was thought to occur when a material was made to release some of its phlogiston. Lavoisier, however, thought the idea was unsound and decided to devise a series of experiments to investigate combustion. By heating different materials in air and carefully weighing them before and after heating, he found that far from losing an ingredient, the materials often appeared to absorb something from the atmosphere. Having heard of the discovery in England of a gas that encouraged the process of burning, Lavoisier showed that the unknown quantity absorbed from the atmosphere during burning was in fact the newly identified gas, which he called oxygen (from the Greek for acid-former). He then defined burning as "the uniting of a substance with oxygen," a definition still used today.
Applying his ideas to combustion in the body, Lavoisier showed that the source of energy is the slow burning of food.
Lavoisier also discovered that the inflammable air discovered by Henry Cavendish (which Lavoisier termed hydrogen, from the Greek for water-former) combined with oxygen to produce a dew, as Joseph Priestley had earlier reported, and which appeared to be water. He further determined that air was a mixture of gases -- primarily nitrogen and oxygen.
Right: Replica of apparatus for hydrogen combustion experiment, made from a sketch by Madame Lavoisier.
Left: Replica of Lavoisier's calorimeter, a piece of equipment for measuring the amount of heat produced by combustion.
Right: Replica of apparatus used by Lavoisier to investigate combustion. He heated mercury in the retort for several days until its whole surface was covered with red particles. During this process the air in the bell jar diminished in volume. Lavoisier found that the air remaining in the ball jar could no longer support either life or combustion. He then heated the red powder which was converted back into mercury. Moreover, the powder gave off a gas equal in volume to that used up in heating the mercury. The gas, identical to the one discovered by Joseph Priestley, enabled substances to burn vigorously and could be inhaled. Lavoisier called the gas oxygen.
Left: A great burning-lens constructed for the French Academy and used by Lavoisier for igniting chemicals. The large lens was made of two pieces of glass and the hollow interior filled with spirit of wine. The movable lens further concentrated the rays of the sun on the substance to be burned.
Lavoisier was not only concerned about discovering underlying concepts in chemistry, but was also convinced of the need to create a technical language capable of expressing those concepts clearly and accurately. Unsatisfied with the fanciful names many chemical substances were given, Lavoisier devised a set of principles by which chemical compounds could be named by referring to the elements of which they were composed. He published his work in a treatise called Methods of Chemical Nomenclature, in 1787. Lavoisier's approach was so logical and straightforward that it was quickly accepted and remains the basis of naming chemicals to this day.
In 1789, Lavoisier published his research on combustion and his ideas about scientific method in what is now considered to be the first modern chemistry textbook, An Elementary Treatise on Chemistry. The book presented a unified view of new theories of chemistry, contained a clear statement of the Law of Conservation of Mass, and denied the existence of phlogiston. Lavoisier also clarified the concept of an element as a simple substance that could not be broken down by any known method of chemical analysis, and devised a theory of the formation of chemical compounds from elements.
Lavoisier's many accomplishments in the field of chemistry were ultimately overshadowed by his association with the Ferme générale. During the Reign of Terror which followed the French Revolution, monarchist tax collectors were hunted down and killed. In 1794, Lavoisier was arrested and brought before a tribunal. The arresting officer silenced the pleas of Lavoisier's colleagues who insisted that his scientific achievements should excuse him with the pronouncement: "The Republic has no need of scientists." Lavoisier was tried, convicted, and guillotined on May 8, 1794.
Other Works by Lavoisier
On Combustion in General
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This page was last updated on 01/24/2013.