[Letter of 1866 April 30]
[Letter of 1866 August 15]
[Letter of 1866 June 16]
[Letter of 1866 June 23]
[Letter of 1867 November 19]
[Letter of 1868 March 5]
[Letter of 1875 December 14]
[Letter of 1875 October 12]
[Letter of 1876 September 7]
[Letter of 1878 July 27]
[Letter of 1879 March 7]