Experiences sur les Vegetaux, Specialement Sur la Propriete qu' ils possedent a un haut degre, soit d' ameliorer l' Air quand ils sont au soleil, soit de le corromprwe la nuit, ou lorsqu'ils sont a l'ombre; auxquelles on a joint Une Methode nouvelle de juger du degre de salubrite de l' Atmosphere [French edition of Experiments upon Vegetables, Translated by Ingen-Housz] [LANDMARK DISCOVERY OF PHOTOSYNTHESIS]

Paris: Theophile Barrois, 1780. 1st French Edition. First French edition published a year after the original and translated by the author. LANDMARK WORK MARKING THE DISCOVERY OF PHOTOSYNTHESIS by JAN INGEN-HOUSZ.

In 1772, a paper by Joseph Priestley’s presented a wealth of achievements, but “the most surprising of... was the discovery of the 'restoration' of air by vegetation” (Priestley, 166).

Though he announced the discovery that plants restored air that had been vitiated by combustion, putrefaction, and respiration, Priestley didn’t yet recognize “the agency of light in the process; he didn’t understand that plants used the 'fixed air' in the atmosphere in a complex process of photosynthesis” (Schofield, The Enlightenment of Joseph Priestley).

One year prior to Priestley’s publication, however, he met privately with the Dutch born physician and chemist Jan Ingen-Housz who, at the very least, was inspired by Priestley’s discovery that plants produce and absorb oxygen from the atmosphere.

“There is no evidence that Ingen-Housz had worked on photosynthesis previously”… but after meeting with Priestley, he began to conduct his own experiments on plant physiology (Dictionary of Scientific Biography). Seven years after their meeting, Ingen-Housz’s own experiments demonstrated his discovery of the mechanism of photosynthesis.

Ingen-Housz’s experiments revealed to him that green plants released bubbles of oxygen in the presence of sunlight, but the bubbles stopped when it was dark—at that point, plants began to emit some carbon dioxide. He had established that “only the green parts of a plant can 'restore' the air, that they do this only when illuminated by sunlight, and that the active part of the sun's radiation is in the visible light and not in the heat radiation.

“In addition, [Ingen-Housz] found that plants, like animals, exhibit respiration, that respiration continues day and night, and that all parts of the plant - green as well as nongreen, flowers and fruits as well as roots - take part in the process" (ibid). Further, he found that plants give off far more oxygen than carbon dioxide, thus identifying the benefits of having greenery around to purify the air” (ibid).

“Priestley was "much pleased" with Ingen-Housz's experiments and pointed immediately to the salient facts that he had established” [Horblit, One Hundred Books Famous in Science, 55].

In a separate listing, we offer first editions of Priestley’s 1772 paper together with the 1779 first edition of Ingen-housz’s volume. Item #1585

CONDITION & DETAILS: 1780. Paris, Théophile Barrois, 8vo. [1], Fold-out frontispiece portrait, [lxviii], 333, [3]. With 1 folded engraved plate depicting Ingen-Housz’s experimental apparatus. Bound in simple half calf contemporary binding; the binding is tight; scuffed at the edge tips; six raised bands at the spine (worn calf) with a small piece missing at the base. Slight toning within, but largely bright and clean throughout. Original wide margins. Very good condition.

DSB VII, pp. 11-16; Garrison & Morton 103; Horblit 55; Dibner 29.

Price: $375.00