(b. Paris, France, 10 February 1747; d. Paris, 27 October 1824)
Thouin spent his entire life at the Jardin des Plantes in Paris. At age seventeen he succeeded his father as head gardener and became responsible for his family’s financial support. He remained unmarried in order to care for his mother, sisters, and brothers, who lived with him in a small apartment in the annex of the old greenhouses. A student of Bernard de Jussieu and Buffon, Thouin assisted the latter in reorganizing the Jardin des Plantes and enriched its greenhouses and the collections of the École de Botanique through many exchanges of plants with foreign botanists. Thouin was a good conversationalist, and his manner was dignified and gentle. His friends included Malesherbes, who filled his pockets with plants and tree branches, and Rousseau, whose misanthropy gave way to openness in Thouin’s company. Thouin also maintained contacts with a number of other naturalists, including Bernardin de Saint-Pierre, Bosc, Desfontaines, and Faujas de Saint-Fond.
An unassuming person who detested pomp, Thouin refused to wear the insignia of the Legion of Honor, which he thought should be reserved for soldiers, and donned the costume of the Institut de France only when obliged to do so. Always generous, he made an interest-free loan of 30,000 francs to a friend who was in difficulties. The money came from a sum left to Thouin by someone who was interested in agriculture and had been impressed by his outstanding integrity.
In collaboration with A. P. de Candolle, in 1806 Thouin observed the influence of light on a number of plants. They used six Argand lamps, believing that they thereby attained five-sixths the intensity of sunlight. Thouin made grafts and noted the influence of the stock on certain characteristics of the graft. He was also an early proponent of the teaching of agriculture and horticulture.
In 1802, with Desfontaines, Thouin made an inventory of the convents in the Paris region, as well as of the property of èmigrès and of those who had been guillotined. The Convention authorized him to dispose of the fruit trees of the Carthusian convent in Paris; this was the origin of the nursery of the Musèum d’Histoire Naturelle. Appointed an army commissioner, Thouin confiscated rich collections in the Low Countries in 1794–1795 and others in Italy two years later. Surviving documents unfailingly show that he carried out his assignments with great honesty. He already had a considerable reputation at age thirty-nine, when he became a member of the Academy of Sciences.
In the last year of his life Thouin fell gravely ill. Realizing that he would soon die, he began to write up his observations and correct his manuscripts. His brother Jean (1756–1827) succeeded him as head gardener; and another brother, Gabriel (1747–1829), also devoted himself to horticulture. Thouin’s herbarium eventually was left to the Faculty of Sciences of Montpellier.
Works published during Thouin’s lifetime are Essai sur l’exposition et la division mèthodique de I’lèconomie rurale (Paris, 1805); Description de l’Ècole d’agriculture pratique de Musèum d’histoire naturelle (n.p., n.d. [Paris, 1814]): and Monographie des greffes ([Paris], 1821 [?]), a technical description of the methods for propagating plants. See also Royal Society Catalogue of Scientific Papers, V , 983–984, which lists 32 works.
His posthumously published writings include Cours de culture et de naturalisation des vègètaux (Paris, 1827), published by his nephew, Oscar Leclerc; Voyage dans la Belgique, la Hollande et l’Italie (Paris, 1841), prepared from Thouin’s journal by Baron Trouvè; and the supplement to François Rozier’s course on agriculture.
Many of Thouin’s articles appeared in Mémoires de la Société d’agriculture; Mémoires de l’Acad’mie des sciences; Dictionnaire d‘histoire naturelle, edited by Dèterville; Annales d‘agriculture française; and the Annales and Mémoires du Muséum national d’histoire naturelle.