(b. Vigny, Val d’Oise, France, 26 May 1669; d. Paris, France, 20 May 1722)
Vaillant, who came from a family of farmers, was interested in plants from the time of his youth. It is reported that he cured himself of an intermittent fever at the age of eight. An organist at Pontoise when he was eleven, he stuided medicine at the hospital there and in 1688 began to practice surgery at Évreux. In 1690 he joined the army as a surgeon and was present at the battle of Fleurus on 1 July. The following year Vaillant moved to Paris, and in 1692 he established himself as a surgeon at Neuilly, working also at the Hôtel-Dieu in Paris. Upon learning that Tournefort was giving courses at the Jardin Royal des Herbes Médicales, usually called Jardin du Roi and now the Jardin des Plantes, he became an assiduous auditor, arriving on foot from Neuilly at five in the morning. Tournefort quickly noticed his gifted and ardent disciple, who brought to class plants collected on his professional rounds and during excursions directed by Tournefort himself.
Vaillant soon left Neuilly to become secretary to Pére de Valois, at whose home he met Guy Fagon, first physician of the king, demonstrator of plants, and later superintendent of the Jardin du Roi. When Fagon arrived, Vaillant was classifying mosses; and Fagon engaged him as secretary. This post gave Vaillant valuable opportunities for collecting plants. The herbarium that he established and steadily expanded was preserved in the Cabinet du Roi until the beginning of the nineteenth century, when it was dispersed in the general herbarium of the Muséum d’Histoire Naturelle, as the whole institution became in the Revolution. Vaillant was put in charge of the garden itself, but Fagon, who highly esteemed his honesty, discretion, and broad botanical knowledge, had him appointed–without his having to request it–assistant demonstrator of plants and then demonstrator of plants. (The latter post had several times been denied to Tournefort.) Vaillant not only had his students collect plants but also lent them his research notes to aid in identification and even allowed them to read his manuscripts.
Louis XIV ordered Vaillant to create a Cabinet de Drogues. Vaillant wished to cultivate exotic plants, however, and Fagon obtained permission from the king to build France’s first greenhouse (1714). When it proved too small, a second greenhouse, twice as large, was built in 1717. In the latter year Vaillant substituted for the titular professor at the Jardin du Roi, and his opening lecture (at six in the morning) drew a large audience. He was so well liked by the students that the professor allowed him to continue to give the course. Many scientists accompanied Vaillant on botanical excursions over a fourteen-year period, notably along the coasts of Normandy and Brittany.
Vaillant’s unstinting dedication to his work undoubtedly aggrevated his asthmatic condition, and his premature death from an unidentified pulmonary disease prevented the publication of some of his manuscripts, notably his inaugural lecture at the Jardin du Roi. In it Vaillant established, on the basis of irrefutable evidence–and for the first time in France–the existence of plant sexuality. (A pistachio tree used in his demonstrations is still alive in the Alpine garden of the Muséum d’Histoire Naturelle.) Also notable are the posthumously published Catalogue des plantes des environs de Paris, often called the “petit botanicon,” and the Botanicon parisiense, properly so called, which was published by Boerhaave from Vaillant’s notes.
The genus Vaillantia (Tournefort) and the species Galium vaillantii and Bulliardia vaillantii are named for Vaillant, who was also interested in mosses, lichens, and fungi. The most favorable and best-founded judgment of Vaillant was made by Linnaeus. Responding to criticisms by a number of botanists, including Dillenius and Jussieu, he declared: “He was a great observer, and every day I become more convinced that no one has been more skillful in establishing genera.”
Botanicon parisiense, ou denombrement . . . des plantes qui se trouvent aux environs de Paris, Hermann Boerhaave, ed. (Leiden-Amsterdam. 1927), contains beautiful plates executed by Claude Aubriet and is preceded by a detailed biography of Vaillant and a full list of his writings.
The most recent article on Vaillant is Jacques Rousseau, “Sébastien Vaillant, an Outstanding 18th-Century Botanist,” in Regnum vegetabile, 71 (1970). 195–228. See also Jean-François Leroy. “La botanique au Jardin des Plantes (1626–1970),” in Adansonia, 2nd ser., 11 . pp. 225–250.