Boyle, Robert (1627–1691), British physicist. Considered one of the fathers of modern chemistry, Boyle is known especially for his pioneering experiments on the properties of gases. In 1662 he published his findings stating the relation concerning the compression and expansion of a gas at constant temperature (Boyle's law). Boyle also wrote the first English treatise on electricity and espoused the theory that matter is corpuscular in composition. This theory was an important forerunner of modern chemical theory.