How did Joseph-Louis Proust's research influence John Dalton's work?

The research of French chemist Joseph-Louis Proust was instrumental in the development of John Dalton's work. Proust established the law of definite proportions, which states that chemical compounds consist of elements combined in fixed, constant proportions by mass.12

Dalton extended this foundational research to formulate his own atomic theory between 1803 and 1808. By proposing that all atoms of a specific element possess the same fixed mass, Dalton provided a theoretical explanation for why elements react in definite proportions: their constituent atoms combine in definite ratios.3

Building further on the law of definite proportions, Dalton deduced the law of multiple proportions, which describes how elements can combine in different ratios to form distinct compounds. Ultimately, Dalton’s atomic theory provided the necessary theoretical framework that helped settle the contemporary scientific dispute between Proust and Claude-Louis Berthollet in favor of Proust’s findings.32