Letter, 10 May 1870
Letter, 6 December 1870
Letter, 11 July 1871
Letter, 10 March 1875
Letter, 29 September 1883
Letter, 26 October 1883
Letter, 26 October 1883
Letter, 20 March 1890
Letter, 26 December 1894
Letter to William Osler, December 15, 1894