The life of a woman entirely devoted to her family duties and to scientific pursuits affords little scope for a biography. There are in it neither stirring events nor brilliant deeds to record; and as my Mother was strongly averse to gossip, and to revelations of private life or of intimate correspondence, nothing of the kind will be found in the following pages. It has been only after very great hesitation, and on the recommendation of valued friends, who think that some account of so remarkable and beautiful a character cannot fail to interest the public, that I have resolved to publish some detached Recollections of past times, noted down by my mother during the last years of her life, together with a few letters from eminent men and women, referring almost exclusively to her scientific works. A still smaller number of her own letters have been added, either as illustrating her opinions on events she witnessed, or else as affording some slight idea of her simple and loving disposition. Few thoughtful minds will read without emotion my mother's own account of the wonderful energy and indomitable perseverance by which, in her ardent thirst for knowledge, she overcame obstacles apparently insurmountable, at a time when women were well-nigh totally debarred from education; and the almost intuitive way in which she entered upon studies of which she had scarcely heard the names, living, as she did, among persons to whom they were utterly unknown, and who disapproved of her devotion to pursuits so different from those of ordinary young girls at the end of the last century, especially in Scotland, which was far more old-fashioned and primitive than England. Nor is her simple account of her early days without interest, when, as a lonely child, she wandered by the seashore, and on the links of Burntisland, collecting shells and flowers; or spent the clear, cold nights at her window, watching the starlit heavens, whose mysteries she was destined one day to penetrate in all their profound and sublime laws, making clear to others that knowledge which she herself had acquired, at the cost of so hard a struggle.