John Dalton was an English chemist, physicist, and meteorologist who made significant contributions to various fields of research. He is best known for introducing the atomic theory into chemistry, which suggested that all matter was comprised of indivisible and indestructible atoms with distinct masses and properties. Daltons atomic theory laid the foundations for the development of all modern chemistry. He also developed methods to calculate atomic weights and structures and formulated the law of partial pressures. Dalton conducted the first-ever research into color blindness, which subsequently became known as Daltonism. He described his method of measuring the masses of various elements, including hydrogen, oxygen, carbon, and nitrogen, according to the way they combine. Daltons experiments on gases led to his discovery that the total pressure of a mixture of gases amounted to the sum of the partial pressures that each gas would exert if it alone occupied the volume. Dalton continued his scientific investigation into a wide range of subjects until his death in 1844.