How did Sir Humphry Davy’s research on chlorine challenge Antoine Lavoisier’s theory of acids?

Sir Humphry Davy’s research on chlorine fundamentally challenged Antoine Lavoisier’s long-held theory that oxygen was the essential "generator of acids" present in all acidic substances.12

Lavoisier had previously hypothesized that oxygen was the fundamental component responsible for acidity. However, Davy demonstrated that chlorine was a chemical element rather than a compound containing oxygen. By showing that chlorine could not be decomposed to reveal oxygen and by clarifying its relationship to hydrochloric acid, Davy proved that the earlier classification of chlorine as "oxymuriatic acid" was incorrect.12

This discovery provided critical evidence that acidity did not require the presence of oxygen, thereby negating Lavoisier’s universal theory of acids. Davy’s work, alongside later findings by other chemists such as Joseph-Louis Gay-Lussac, forced a significant shift in chemical understanding regarding the nature of acids and elemental composition.23