Robert Boyle, 17th century Irish natural philosopher, (c1850).

Robert Boyle, 17th century Irish natural philosopher, (c1850). Boyle (1627-1691) was the seventh son of the first Earl of Cork. After Eton he travelled extensively in Europe, before commencing (with his assistant Robert Hooke) experiments on improving the air pump invented by Otto von Guericke. Boyle's many experiments on air, vacuum, combustion, and respiration led to the publication in 1661 of his The Sceptical Chymist, in which he criticised current theories of matter, particularly those relating to alchemy. In 1662 he formulated Boyle's Law, which states that the pressure and volume of gas are inversely proportional. He was a founder member of the Royal Society, though in 1680 he refused to become their first president as he was unwilling to take the oath of allegiance to the monarchy. Taken from the book Old England's Worthies. (London, c1850). (Photo by The Print Collector/Print Collector/Getty Images)