FACE PAGE Mrs. Nightingale and her two Daughters: 1828. (_From a water-colour drawing in possession of Mrs. Cunliffe_) _Frontispiece_ Florence Nightingale about 1845. (_From a pencil drawing by her cousin, Miss Hilary Bonham Carter, in possession of Miss B. A. Clough_) 38 Florence Nightingale: about 1858. (_From a photograph by Goodman_) 394 INTRODUCTORY Among Miss Nightingale's memoranda on books and reading, there is this injunction: "The preface of a book ought to set forth the importance of what it is going to treat of, so that the reader may understand what he is reading for." The saying is typical of the methodical and positive spirit which, as we shall learn, was one of the dominant strains in Miss Nightingale's work and character. She wanted to know at every stage precisely what a person, or a book, or an institution was driving at. "Of all human sounds," she said, "I think the words _I don't know_ are the saddest." Unless a book had something of definite importance to say, it had better, she thought, not be written; and in order to save the reader's time and fix his attention, he should be told at once wherein the significance of the book consists. This, though it may be a hard saying, is perhaps not unwholesome even to biographers. At any rate, as Miss Nightingale's biographer, I am moved to obey her injunction. I propose, therefore, in this Introductory chapter to state wherein, as I conceive, the significance and importance of Miss Nightingale's life consists, and what the work was that she did in the world. I