Title page of The Sceptical Chymist by Robert Boyle, c 1661.

UNITED KINGDOM - SEPTEMBER 04: Boyle (1627-1691), seventh son of the first Earl of Cork, and his assistant Robert Hooke worked on improvements to the air pump invented by Otto von Guericke. Boyle's many experiments on air, vacuum, combustion, and respiration resulted the publication of 'The Sceptical Chymist', (London, 1661), a masterpiece of scientific literature in which he criticised confused theories then current, in particular those relating to alchemy. He claimed that there were more than the four Aristotelian elements - earth, water, air and fire - and that matter is composed of atoms and clusters of atoms in motion. In 1662 he formulated Boyle's Law, which states that the pressure and volume of gas are inversely proportional. Boyle was one of the first chemists to prepare phosphorus. (Photo by SSPL/Getty Images)