---
title: "History of chemistry"
chunk: 6/20
source: "https://en.wikipedia.org/wiki/History_of_chemistry"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:59:28.102404+00:00"
instance: "kb-cron"
---

Repeating the experiments of Priestley, he demonstrated that air is composed of two parts, one of which combines with metals to form calxes. In Considérations Générales sur la Nature des Acides (1778), he demonstrated that the "air" responsible for combustion was also the source of acidity. The next year, he named this portion oxygen (Greek for acid-former), and the other azote (Greek for no life). Because of his more thorough characterization of it as an element, Lavoisier thus has a claim to the discovery of oxygen along with Priestley and Scheele. He also discovered that the "inflammable air" discovered by Cavendish – which he termed hydrogen (Greek for water-former) – combined with oxygen to produce a dew, as Priestley had reported, which appeared to be water. In Reflexions sur le Phlogistique (1783), Lavoisier showed the phlogiston theory of combustion to be inconsistent. Mikhail Lomonosov independently established a tradition of chemistry in Russia in the 18th century; he also rejected the phlogiston theory, and anticipated the kinetic theory of gases. Lomonosov regarded heat as a form of motion, and stated the idea of conservation of matter.
Lavoisier worked with Claude Louis Berthollet and others to devise a system of chemical nomenclature, which serves as the basis of the modern system of naming chemical compounds. In his Methods of Chemical Nomenclature (1787), Lavoisier invented the system of naming and classification still largely in use today, including names such as sulfuric acid, sulfates, and sulfites. In 1785, Berthollet was the first to introduce the use of chlorine gas as a commercial bleach. In the same year he first determined the elemental composition of the gas ammonia. Berthollet first produced a modern bleaching liquid in 1789 by passing chlorine gas through a solution of sodium carbonate – the result was a weak solution of sodium hypochlorite. Another strong chlorine oxidant and bleach which he investigated and was the first to produce, potassium chlorate (KClO3), is known as Berthollet's Salt. Berthollet is also known for his scientific contributions to the theory of chemical equilibrium via the mechanism of reversible reactions.

Lavoisier's Traité Élémentaire de Chimie (Elementary Treatise of Chemistry, 1789) was the first modern chemical textbook, and 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. In addition, it contained a list of elements, or substances that could not be broken down further, which included oxygen, nitrogen, hydrogen, phosphorus, mercury, zinc, and sulfur. His list, however, also included light and caloric, which he believed to be material substances. In the work, Lavoisier underscored the observational basis of his chemistry, stating "I have tried...to arrive at the truth by linking up facts; to suppress as much as possible the use of reasoning, which is often an unreliable instrument which deceives us, in order to follow as much as possible the torch of observation and of experiment." Nevertheless, he believed that the real existence of atoms was philosophically impossible. Lavoisier demonstrated that organisms disassemble and reconstitute atmospheric air in the same manner as a burning body.
With Pierre-Simon Laplace, Lavoisier used a calorimeter to estimate the heat evolved per unit of carbon dioxide produced. They found the same ratio for a flame and animals, indicating that animals produced energy by a type of combustion. Lavoisier believed in the radical theory, which stated that radicals, which function as a single group in a chemical reaction, would combine with oxygen in reactions. He believed all acids contained oxygen. He also discovered that diamond is a crystalline form of carbon.
Although many of Lavoisier's partners were influential for the advancement of chemistry as a scientific discipline, his wife Marie-Anne Lavoisier was arguably the most influential of them all. Upon their marriage, Mme. Lavoisier began to study chemistry, English, and drawing in order to help her husband in his work either by translating papers into English, a language which Lavoisier did not know, or by keeping records and drawing the various apparatuses that Lavoisier used in his labs. Through her ability to read and translate articles from Britain for her husband, Lavoisier had access to knowledge of many of the chemical advances happening outside of his lab. Furthermore, Mme. Lavoisier kept records of her husband's work and ensured that his works were published. The first sign of Marie-Anne's true potential as a chemist in Lavoisier's lab came when she was translating a book by the scientist Richard Kirwan. While translating, she stumbled upon and corrected multiple errors. When she presented her translation, along with her notes, to Lavoisier, her contributions led to Lavoisier's refutation of the theory of phlogiston.
Lavoisier made many fundamental contributions to the science of chemistry. Following his work, chemistry acquired a strict, quantitative nature, allowing reliable predictions to be made. The revolution in chemistry which he brought about was a result of a conscious effort to fit all experiments into the framework of a single theory. He established the consistent use of chemical balance, used oxygen to overthrow the phlogiston theory, and developed a new system of chemical nomenclature. Further potential contributions were cut short when Lavoisier was beheaded during the French Revolution.