Which experiments helped Antoine Lavoisier disprove the phlogiston theory?

Antoine Lavoisier did not merely disprove the phlogiston theory by identifying its errors; he replaced it with an experimentally grounded theory of combustion and oxidation through rigorous, quantitative research.1

His key experiments included:

• Weight Analysis of Calcination: In the early 1770s, Lavoisier observed that when metals like tin or lead were heated to form "calxes" (metallic ashes), the resulting product weighed more than the original metal. This contradicted the phlogiston theory, which suggested that metals lost phlogiston during combustion.21
• Tracking Gases: By using precise measurements to account for all substances entering and leaving reactions, Lavoisier demonstrated that the weight gain in metals and nonmetals (such as sulfur and phosphorus) was due to the absorption of a specific gas from the atmosphere.34
• Oxygen Identification: After learning of Joseph Priestley’s discovery of "dephlogisticated air," Lavoisier repeated the experiments and identified this gas as the active component in combustion and respiration, naming it oxygen.315

By proving that combustion involved the chemical combination of a substance with oxygen rather than the release of a hypothetical "fiery substance," Lavoisier established the conservation of mass as a fundamental principle of chemistry.34