Letter to John George Adami, January 3, 1914
Letter to Richard Pearson Strong, January 1, 1919
Letter to George Sarton, (5,? 1917?)
Letter, 30 January 1872
Letter to Herbert Stanley Birkett, July 16, 1914
Letter to Harry Friedenwald, January 4, 1915
Letter to Alexander Dougall Blackader, July 13, 1916
Letter to Arthur T. Hadley, July 10, 1912
Letter to Thomas Archibald Malloch, July 4, 1918
Letter to M.W. Blogg, January 3, 1919