Boyle and his laboratory assistant Papin, 1675. Robert Boyle (1627-1691) was a 17th century natural philosopher, chemist, physicist, and inventor, also noted for his writings in theology. 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. Among his works, The Sceptical Chymist is seen as a cornerstone book in the field of chemistry. Denis Papin (1647-1712) was a French physicist, mathematician and inventor, best known for his pioneering invention of the steam digester, the forerunner of the steam engine and of the pressure cooker. He worked with British chemist Robert Boyle.