John Dalton an English chemist and physicist who developed the atomic theory of matter in 1803 and hence is known as one of the fathers of modern physical science. Dalton arrived at his view of atomism by way of meteorology. He recorded over 200,000 observations of the atmosphere in his notebooks. This led him to his atomic theory of matter in which he was the first to associate the ancient idea of atoms (atoms had been described 2,000 years earlier) with stoichiometry. Dalton’s atomic theory rests on four postulates: 1) All matter consists of tiny particles; 2) Atoms are indestructible and unchangeable; 3) Elements are characterized by the mass of their atoms, and 4) When elements react, their atoms combine in simple, whole-number ratios. Dalton also was the first to provide a scientific description of color blindness in 1794, a condition from which he suffered and which was long called "Daltonism."