This work contains the first demonstration that the emission of oxygen by green plants in sunlight is strictly dependent on a supply of carbon dioxide. This is the first and most significant of Jean Senebier’s four works on photosynthesis. Across three volumes, Senebier presents extensive qualitative and quantitative experiments on the effects of sunlight on plants, repeating many of Ingenhousz’s trials but often arriving at more precise or revised conclusions. The third volume broadens the inquiry, including shorter memoirs on the influence of light on animal and mineral substances, as well as on the nature of light itself. Senebier also extends the experiments of Carl Wilhelm Scheele on light-induced changes - testing the darkening of materials under differently colored light - and examines the effects of sunlight on dyes, paints, and colored fabrics. The book shows tears, creasing and folded corners, occasional worming; some leaves trimmed with losses to page edges, not affecting the text. A scarce and scientifically important work, marking a decisive advance in the early study of photosynthesis. Vol. I: xvi, 408 pp., with 2 folding engraved plates. Vol. II: viii, 411 pp. Vol. III: viii, 412 pp.