---
title: "Antoine Lavoisier"
chunk: 5/8
source: "https://en.wikipedia.org/wiki/Antoine_Lavoisier"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:07:05.583915+00:00"
instance: "kb-cron"
---

=== Pioneer of stoichiometry ===
Lavoisier's researches included some of the first truly quantitative chemical experiments. He carefully weighed the reactants and products of a chemical reaction in a sealed glass vessel so that no gases could escape, which was a crucial step in the advancement of chemistry. In 1774, he showed that, although matter can change its state in a chemical reaction, the total mass of matter is the same at the end as at the beginning of every chemical change. Thus, for instance, if a piece of wood is burned to ashes, the total mass remains unchanged if gaseous reactants and products are included. Lavoisier's experiments supported the law of conservation of mass. In France it is taught as Lavoisier's Law and is paraphrased from a statement in his Traité Élémentaire de Chimie: "Nothing is lost, nothing is created, everything is transformed." Mikhail Lomonosov (1711–1765) had previously expressed similar ideas in 1748 and proved them in experiments; others whose ideas pre-date the work of Lavoisier include Jean Rey (1583–1645), Joseph Black (1728–1799), and Henry Cavendish (1731–1810).

=== Chemical nomenclature ===

Lavoisier, together with Louis-Bernard Guyton de Morveau, Claude-Louis Berthollet, and Antoine François de Fourcroy, submitted a new program for the reforms of chemical nomenclature to the academy in 1787, for there was virtually no rational system of chemical nomenclature at this time. This work, titled Méthode de nomenclature chimique (Method of Chemical Nomenclature, 1787), introduced a new system which was tied inextricably to Lavoisier's new oxygen theory of chemistry.
The classical elements of earth, air, fire, and water were discarded, and instead some 33 substances which could not be decomposed into simpler substances by any known chemical means were provisionally listed as elements. The elements included light; caloric (matter of heat); the principles of oxygen, hydrogen, and azote (nitrogen); carbon; sulfur; phosphorus; the yet unknown "radicals" of muriatic acid (hydrochloric acid), boric acid, and "fluoric" acid; 17 metals; 5 earths (mainly oxides of yet unknown metals such as magnesia, baria, and strontia); three alkalies (potash, soda, and ammonia); and the "radicals" of 19 organic acids.
The acids, regarded in the new system as compounds of various elements with oxygen, were given names which indicated the element involved together with the degree of oxygenation of that element, for example sulfuric and sulfurous acids, phosphoric and phosphorous acids, nitric and nitrous acids, the "ic" termination indicating acids with a higher proportion of oxygen than those with the "ous" ending.
Similarly, salts of the "ic" acids were given the terminal letters "ate," as in copper sulfate, whereas the salts of the "ous" acids terminated with the suffix "ite," as in copper sulfite.
The total effect of the new nomenclature can be gauged by comparing the new name "copper sulfate" with the old term "vitriol of Venus." Lavoisier's new nomenclature spread throughout Europe and to the United States and became common use in the field of chemistry. This marked the beginning of the anti-phlogistic approach to the field.

=== Chemical revolution and opposition ===
Lavoisier is commonly cited as a central contributor to the chemical revolution. His precise measurements and meticulous keeping of balance sheets throughout his experiment were vital to the widespread acceptance of the law of conservation of mass. His introduction of new terminology, a binomial system modeled after that of Linnaeus, also helps to mark the dramatic changes in the field which are referred to generally as the chemical revolution. Lavoisier encountered much opposition in trying to change the field, especially from British phlogistic scientists. Joseph Priestley, Richard Kirwan, James Keir, and William Nicholson, among others, argued that quantification of substances did not imply conservation of mass. Rather than reporting factual evidence, opposition claimed Lavoisier was misinterpreting the implications of his research. One of Lavoisier's allies, Jean Baptiste Biot, wrote of Lavoisier's methodology, "one felt the necessity of linking accuracy in experiments to rigor of reasoning." His opposition argued that precision in experimentation did not imply precision in inferences and reasoning. Despite opposition, Lavoisier continued to use precise instrumentation to convince other chemists of his conclusions, often results to five to eight decimal places. Nicholson, who estimated that only three of these decimal places were meaningful, stated: 

If it be denied that these results are pretended to be true in the last figures, I must beg leave to observe, that these long rows of figures, which in some instances extend to a thousand times the nicety of experiment, serve only to exhibit a parade which true science has no need of: and, more than this, that when the real degree of accuracy in experiments is thus hidden from our contemplation, we are somewhat disposed to doubt whether the exactitude scrupuleuse of the experiments be indeed such as to render the proofs de l'ordre demonstratif.

== Notable works ==