Robert Boyle's third air-pump, double-barreled, 1682. Robert Boyle (1627-1691) was a 17th-century natural philosopher, chemist, physicist, and inventor. Though his research clearly has its roots in the alchemical tradition, Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of modern chemistry, and one of the pioneers of modern experimental scientific method. He is best known for Boyle's law, which describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system. Using air pumps, Boyle devised experiments to explore the properties of air.