In three sections, this article, building on David Knight’s early and important (but brief) assessment of the character of Humphry Davy’s (1778–1829) notemaking, presents and examines three of the main uses of Davy’s notebooks: as spaces or sites for experimentation; for projection; and for preservation. After providing an introductory overview of Davy’s notebook collection, it presents key readings, tied closely to Davy’s biography, of Davy notebooks from his early (notebooks 13C, 13E, 21B, 22A and 22C), middle (06 and 07), and later (14E) years. It also suggests ways in which we might apply organizing or guiding principles to what, on the surface, may appear to be a heterogeneous mass of almost overwhelmingly disparate information, and, taking a primarily comparative approach throughout, of interpreting Davy’s notebook collection as a whole.