Robert Boyle, Irish physicist and chemist, 17th century.
© Science Museum / Science & Society Picture Library
Engraving by J Chapman of Boyle (1627-1691), who with his asistant 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 in the publication in 1661 of 'The Sceptical Chymist', in which he criticised current theories of matter, in particular those relating to alchemy. In 1662 he formulated Boyle's Law, which states that the presure and volume of gas are inversely proportional. He was a founder member of the Royal Society, but refused to become their first president as he was unwilling to take the oath of allegiance to the monarchy. Illustration from 'Encyclopaedia Londinensis, or, Universal Dictionary of Arts, Sciences, and Literature' published in London, 1810-1829.