Laboratory notebook used by Clara Esther Hartley during a high school-level chemistry class in Troy, Ohio. The notebook details approximately 115 experiments performed by Hartley, ranging from fundamental investigations such as "Is Wood an Element?," to more advanced concepts dealing with the production, decomposition, and solubility of carbon dioxide. Notably, miscellaneous notes at the end of the volume include an analysis of drinking water drawn from the well of a local resident. In her analysis, Hartley notes sources of pollution and finds traces of chloride and nitrates in excess of 425 mg, leading her to conclude "This water is to [sic] foul to be used for drinking."

Hartley's numbering of experiments runs from 1 to 122; however, the following experiments are not recorded in the notebook: 77, 90, 95, 106, 109, and 120. Additionally, there are a series of blank pages after experiment 122 and in the "Miscellaneous" section of the notebook, which were omitted during digitization.