Early modern efforts to reconceptualize atomicity as a chymical notion fell by the wayside during the chemical revolution, as Antoine Lavoisier’s desire to transform chemistry into a strictly empirical and quantitative science led him to reject all metaphysical speculation about the fundamental nature of matter. Instead, Lavoisier focused on identifying elementary substances, which he defined operationally as the final products of chemical analysis.
Our current understanding of the relation between atoms and elements, however, owes a great deal to the work of nineteenth-century chemist John Dalton. Dalton’s chemical atomic theory reconciled the concepts of “atomicity” and “elementarity” and rendered both as empirical and chemical notions, amenable to measurement and quantitative analysis.
One of the central goals of Dalton’s theory was understanding how relative weights of chemical atoms determine the properties of elements and how the chemical atoms of different elements combine to form compound substances. Thus, Dalton’s theory provided a way of studying and measuring the properties of atoms and elements in a way that allowed chemists to finally understand the chemical relations between them.