John Dalton (1766-1844)
English scientist, born in Eaglesfield, in September 6th 1766, and died in Manchester, in July 27th 1844, is the founder of atomic theory.
Dalton started his career as a school teacher, devoting his time to the study of Mathematics and Physics, while teaching in Manchester. In 1794 studied the phenomena that later became known as daltonism. After that he started to study Chemistry, the physical behavior of gases and in 1803 proposed the principles of atomic theory to explain the constitution of matter. Dalton is therefore the main responsible for the scientific approach to the old theories of Democritus.