Then
His “Elements of Chemistry” and the oxygen theory ended the phlogiston era and gave chemistry a clear language and conservation law.
Timeline of Discovery · 15 / 30
Antoine Lavoisier
1743 - 1794 · France
Antoine Lavoisier reframed chemistry around careful measurement and named oxygen, sweeping away the old “phlogiston” theory of burning.
- Chemistry
- Industrial & Modern
Lived
1743 - 1794
Era
Industrial & Modern
Primary field
Chemistry
Signature idea
Father of modern chemistry; law of conservation of mass
Their place in history
1743 - 1794
The question they asked
What actually happens to matter when things burn, rust or react?
The Contribution
What this scientist actually did — precisely and plainly.
He showed that combustion and respiration involve a gas, later named oxygen, and that mass is conserved in chemical reactions — turning chemistry into a quantitative science.
How the Work Advanced Knowledge
The tools, experiments and reasoning behind the discovery.
He used balances to weigh reactants and products precisely, designed closed-system experiments, and applied naming rules that chemists still follow.
Why It Mattered Then / Today
From their own moment in history to the world we live in now.
Today
Stoichiometry, chemical equations and the conservation of mass are fundamental; modern chemistry and energy science descend directly from his balance.
Important Works or Discoveries
Landmarks that carried the idea into the world.
- Elements of Chemistry (Traité élémentaire)
- The oxygen theory of combustion
- The law of conservation of mass
Nothing is lost, nothing is created, everything is transformed.
Sources
Where this profile was verified.
Last reviewed: 2026-09-22
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