Sir Kenelm Digby, English author, naval commander and diplomatist, c 1645.
© Science Museum / Science & Society Picture Library
Engraving by J Houbraken from a painting by Anthony Van Dyke. Sir Kenelm Digby (1603-1665) discovered the necesity of oxygen to the life of plants. A friend of Charles I, Digby was knighted in 1623 and helped found the Royal Society in 1663.