Structure of Matter

The concept ofmatter composed of empty space filledwith small indivisible particles hadbeen

proposed as early as several centuries BC, in particular by the Greek Demokritos. However, the

Aristotelean concept of continuous matter prevailed for centuries until the development, circa

1800, of modern quantitative chemistry by scientists including A.L. de Lavoisier, J. Dalton, J.L.

Gay-Lussac,A.Avogadro, andL.J. Proust. Theirworkdeveloped the principle of the composition

of compound materials from well-defined proportions of chemical elements.