Duhamel Du Monceau, Henri-Louis

(b Paris, France, 1700; d. Paris, 23 August 1782)

agronomy, chemistry, botany, naval technology.

The son of Alexandre Duhamel (the name can be found variously listed as Hamel, du Hamel, or Monceau), seigneur of the estate of Denainvilliers in Gâtinais, Duhamel was a wealthy but minor member of the French landed gentry. Although the stories about Duhamel’s problems at the Collège d’Harcourt have been rather exaggerated for effect, there is little doubt that he began to apply himself seriously only after hearing science lectures at the Jardin du Roi in the 1720’s. During this time he became acquainted with the younger group of French scientists, such as the chemist Charles-François Dufay and the botanist Bernard de Jussieu, as well as with such established members of the scientific community as Louis Lémery and Étienne-François Geoffrey.

Duhamel first achieved scientific recognition with his explanation of the cause of a blight which attacked the saffron plant with particular ferocity in the 1720’s. This study, unusual from its inception because it was given by the Academy to a nonmember, showed that the disease was caused by a plant parasite which spread underground from one saffron bulb to another. The work, read to the Academy in April 1728, was well-conceived, thorough, and conclusive, and led to his election as adjoint chimiste in the same year.

The choice of position was partly due to a lack of openings in botany, but it was not unreasonable in absolute terms since Duhamel’s breadth of interests was somewhat surprising even for an eighteenthcentury polymath. Moreover, although his early researches for the Academy were devoted to botanical subjects, he undertook a series of chemical investigations in the early 1730’s in collaboration with the chemist Jean Grosse. These included an attempt to make tartar soluble and the well-known study of Frobenius’ ether, which, if one can accept Duhamel’s testimony, was carried out largely by Grosse. In the mid-1730’s Duhamel investigated contrasting claims for the synthesis of sal ammoniac and examined the nature of the purple dye commonly obtained from shellfish. His most important work in chemistry during this period was “Sur la base du sel marin,” read in January 1737, in which he argued that there were different fixed alkaline components of salts and that these were essentially soda and potash. Although challenged by the German chemist J. H. Pott, Duhamel made this important idea credible. He occasionally undertook chemical projects in later years, but other interests, primarily botany and agronomy, occupied most of his remaining working life. One of these interests was in the cultivation and use of timber. With his primary interest in plants, Duhamel was made associé botaniste of the Academy in 1730; and in 1732 he was appointed inspecteur général de la marine, with the understanding that his duties would include supervising the timber to be used in the French navy. His experiences in this position led to several studies published in the 1740’s on the structural properties of wood and on management of tree stands, and to his first book (1747), a treatise on the rigging of ships.

But Duhamel’s major interest and contribution to technology and society was in agriculture. The first half of the eighteenth century had witnessed the beginning of a technological renaissance in agriculture, chiefly in England, where it was notably celebrated in the writings of Jethro Tull, whose major work, Horse-Hoeing Husbandry, was published in 1733. As the work of the progressive English landed gentry began to bear fruit, traveling French savants were quick to publish critical comparisons of French and English practices. In 1750, stimulated by a trip to England and by wide reading in agronomy, Duhamel published the first volume of his Traité de la culture des terres.... This was an exposition, rather than a translation, of Tull’s writings. Moreover, he adapted Tull’s system to France based on his own wide reading in French agronomy and on original experiments. Although a supporter and admirer of Tull’s system, he was not a slavish disciple: not only was he critical of Tull’s experiments and ideas, but he refused to accept one of Tull’s central principles, a doctrinaire rejection of the use of manures. Later volumes of the Traité were devoted to clarifications of and additions to the original work and, most important, to case histories—most of which were gleaned from Duhamel’s extensive correspondence—of successful applications of the nouveau système to support its adherents.

Although the ideas of Tull and Duhamel enjoyed substantial popularity among a progressive group of French landowners, the opposition—either in the form of active criticism or in the passive inertia of an almost medieval agrarian society—was too strong for France to enjoy the rapid agricultural changes which occurred in England and, shortly after, in Scotland. However, enough progress was made for Duhamel to receive recognition for his pioneering work during his lifetime.

Duhamel never married and, according to one biographer, never planned or desired to do so. He divided his time between Paris and Denainvilliers, where his brother carried out many of the agricultural projects which Duhamel designed, and managed the family fortune that allowed Duhamel to pursue various experiments of his own. When his brother died, Duhamel was looked after by a niece and particularly by his nephew and protégé, Fougeroux de Bondaroy. Straightforward in speech and thought. Duhamel consciously wrote for an audience of technicians rather than scientists. Although his later writings reflect the professed distaste for theory that Condorcet attributed to him, his papers as a whole were not as barren of interpretation as one might suppose from his biographers. Indeed, that his works include ideas as well as simple techniques is amply attested by those who disagreed with his papers and treatises, as well as by the honors he received from more than a dozen learned societies.

BIBLIOGRAPHY

Duhamel had the habit of writing supplements to his books, sometimes years after the original publication. As the supplements were book-length themselves, they were frequently issued as “Vol. II” of the original and sometimes there were minor changes in the titles. The Traité. … des terres thus grew from a one-volume work to a six-volume work and generally bears the dates 1753 (the year of publication of the second supplement as part of a set that included the original and first supplement) and 1761 (the year of the final supplement). I have, however, given original publication dates and not the dates of reissues; that is, all dates in the text and below are those years in which Duhamel’s works were first made available to the public.

I. Original Works. Duhamel is credited with over a hundred entries in the Histoires de l’Académie royale des sciences, avec des mémoires de mathématique et de physique. Although he was certainly prolific, this figure is somewhat misleading. More than a third of the mémoires under his name are his “Observations botanico-médtéorologiques,” an intellectually routine annual series (1740–1780) of recorded daily weather conditions, including temperature and barometric pressure, with additional data on crops, floods, and plant growth in general. But even subtracting histoires, reviews of his books, and the “Observations,” Duhamel contributed some fifty-five papers to the French Academy. In addition, he wrote a score of articles for the Descriptions des arts et métiers (1760–1775). A few contributions to other journals are also known.

His impressive output of separate works includes Traité de la fabrique des manoeuvres pour les vaisseaux ou l’art de la corderie perfectionné, 2 vols. (Paris, 1747–1769); Traité de la culture des terres suivant les principes de M. Tull, 6 vols. (Paris, 1750–1761); Eléments de l’architecture navale (Paris, 1752); Avis pour le tránsport par mer des arbres, des plants vivaces, des semences, et de diverses autres curiosités d’histoire naturelle (Paris. 1753); Traiti de la conservation des grains et en particulier dufroment (Paris, 1753); Traité des arbres et arbustes qui se cultivent en France en pleine terre, 2 vols. (Paris, 1755); Mémoires sur la garance et sa culture (Paris, 1757); La physique des arbres, 2 vols. (Paris, 1758); Moyens de conserver la santé aux équipages desvaisseaux(Paris, 1759); Des semis et plantations des arbres et de leur culture (Paris, 1760); Élements d’agriculture, 2 vols. (Paris, 1762); Histoire d’un insecte qui dévore les grains dans l’Angoumois (Paris, 1762); De l’exploitation des bois, 2 vols. (Paris, 1764); Du transport, de la conservation et de la force des bois (Paris, 1767); Traitédes arbres fruitiers, 2 vols. (Paris, 1768); Traitégéneral des peches, et histoire des poissons qu’elles fournissent, 3 vols. (Paris, 1769–1777). There are various translations in English, German, Spanish, and Italian.

II. Secondary Literature. Most biographies rely heavily on the éloge by Condorcet in the Histoire de l’Académie royale des sciences... 1782 (1785). 131–155.

Other material may be found in Biographic universelle, ancienne et moderne, XII (Paris, 1814), 185–190; Dictionnaire de biographie française (Paris, 1968), p. 22; Dictionnaire historique de la médecine, ancienne et moderne, II, pt. I (Paris, 1834), 147–149; Dictionnaire des sciences médicates, III (Paris, 1821), 538–541; Nouvelle biographie générale, XV (Paris, 1868), 106–107.

Jon Eklund