John Mitchinson Calvert (1802-1842): The eldest son of William Calvert. He became a doctor and friend of the Scottish writer John Sterling (1806–1844; DNB), and through Sterling, made the acquaintance of Thomas Carlyle (1795–1881; DNB) and John Stuart Mill (1806–1873; DNB). Calvert suffered from tuberculosis and died at Falmouth on his way to Madeira.