Key points are not available for this paper at this time.
FOREWORD TO VOLUME XVI The Journals: 1866-1882 Chronology Symbols and Abbreviations PART ONE The Texts of the Journals LN NY ST PART TWO The Texts of the Miscellaneous Notebooks Books Large Pocket Diary 17 Pocket Diary 18 Pocket Diary 19 Pocket Diary 20 Pocket Diary 21 Pocket Diary 22 Pocket Diary 23 Pocket Diary 24 Pocket Diary 25 Pocket Diary 26 Pocket Diary 27 Pocket Diary 28 Pocket Diary 29 Pocket Diary 30 Pocket Diary 31 Appendix I Journals and Notebooks in the Harvard Edition Appendix II Author and Title Entries in Notebook Books Large Textual Notes Index
Spiller et al. (1962) studied this question.