For permission to print letters written to Miss Nightingale, I am indebted to many of her relations, friends, and correspondents, or their representatives; to so many, indeed, that I ask them to accept here a general acknowledgment. I am especially indebted to the King, who has been pleased to permit the publication of letters from Queen Victoria and some other members of the Royal Family. The German Emperor has graciously given a like permission in the case of correspondence with the Empress Frederick. The Dowager Grand Duchess (Luise) of Baden has allowed me to quote from a long series of letters addressed by her to Miss Nightingale. * * * * * Next to the letters and other papers, above described, the most valuable material for the Life of Miss Nightingale is contained in her own printed writings--many of them published, some (and these, from the biographical point of view, the most important) privately printed. In the case of the Crimean War, material under both of these heads is particularly abundant. Her published _Notes on Hospitals_ and _Notes on Nursing_ and other works relating to those subjects, together with her privately circulated _Addresses to Probationers_, supplement her private records. For her inner life, her privately printed book, Suggestions for Thought, is of special importance. A List of Miss Nightingale's Printed Writings (whether published or privately circulated) is given at the end of the second volume (_Appendix A_). My purpose in compiling this List was biographical illustration, not bibliographical minuteness. I have not included every scrap from Miss Nightingale's pen which has appeared in print, but have given every piece which is directly or indirectly referred to in the Memoir, or which is of any importance. The List will, I hope, serve a double purpose. It enables me to abbreviate in the text the references to my authorities; and it provides, in chronological order, a conspectus of Miss Nightingale's varied activities, so far as they were reflected in her printed writings.