John Dalton was born in September 6, 1766 in Eaglesfield England. He was the youngest of three siblings. In 1793 he teached in Manchester. John passed away in July 28, 1844.
He did gas experiments to develop the modern theory of atom in 1803. In 1807 john had "rewritten" the theory he made in 1803 because he had looked at other scientist like Richter, who had worked alot on the theory. A theory that he had was the atmosphere was 80 percent nitrogen and 20 percent oxygen. He studied about blindness, he was also the first scientist to explain the behavior of atoms.