John Dalton was an English chemist most famous for proposing atomic theory. He proposed atomic theory in 1803, which states that all matter is composed of small indivisible particles called atoms. It also stated that the atoms of each element had distinct characteristics and weight. Dalton’s theory was in direct opposition to Isaac Newton’s theory of chemical affinities, which was popular at that time.
Dalton was extremely interested in meteorology. He often read his papers on meteorology to the Literary and Philosophical Society, and continued to do so from 1799 to 1801. In 1793, Dalton published his first book on meteorology, "Meteorological Observations." Dalton's extensive research on meteorology eventually helped in the development of his atomic theory proposal, which he launched two years after he stopped reading his papers at the Literary and Philosophical Society. Dalton also understood that atoms were different in weight and composition. Accordingly, he calculated atomic weight from the ratios of the weights of the reactants and proposed that chemical elements combine in ratios. During his lifetime, Dalton also famously refuted the theory of Antoine Laurent Lavoisier, who thought that air was a vast chemical solvent. Dalton is also known for suffering from colorblindness, which is sometimes still referred to as "Daltonism."