Joseph Wright of Derby.
Erasmus Darwin.
c.1770. Oil on canvas. 76 x 63.5 cm. Darwin College, Cambridge, UK. More. 
Erasmus Darwin was the seventh child of a lawyer, Robert Darwin of Elston and his wife, Elizabeth Hill. Erasmus grew up to be a successful physician, even receiving an invitation to serve as the Royal Physician of King George III. He is also the grandfather of the famous naturalist, Charles Darwin.
See Also: Joseph Wright of Derby. Erasmus Darwin.