Dalton's wooden atomic models, c.1810

These wooden balls were the first models made to represent atoms and were used by John Dalton (1766-1844) to demonstrate atomic theory. He stated that matter is made up of small indivisible particles, or solid atoms. In 1808 Dalton published a small book entitled A New System of Chemical Philosophy, Part 1, which had an enormous influence on the development of both chemistry and physics.