Ultimate Particles - Marc'Antonio Mazzoleni collection.

English chemist and physicist John Dalton extended Proust’s work and converted the atomic philosophy of the Greeks into a scientific theory between 1803 and 1808. His book A New System of Chemical Philosophy (Part I, 1808; Part II, 1810) was the first application of atomic theory to chemistry. It provided a physical picture of how elements combine to form compounds and a phenomenological reason for believing that atoms exist. Dalton claimed that atoms of different elements vary in size and mass, and indeed this claim is the cardinal feature of his atomic theory. His argument that each element had its own kind of atom was counterintuitive to those who believed that having so many different fundamental particles would destroy the simplicity of nature, but Dalton dismissed their objections as fanciful. His work, together with that of Joseph-Louis Gay-Lussac of France and Amedeo Avogadro of Italy, provided the experimental foundation of atomic chemistry.

Britannica — The beginnings of modern atomic theory.
Plate 4: Elements — Courtesy of Science History Institute

Get a Giclée print