Louis, a French writer of some celebrity, was born at Tours, of Protestant parents, Jan. 15, 1730. In his youth he devoted himself to poetry; and in 1748 he repaired to Paris and composed a tragedy, entitled The Return of Ulysses to Ithaca, which he showed to the comedian Lanoue, requesting him to bring it on the stage. The latter, however, returned the piece, advising the author to retouch it. Irritated at this advice, Dutens went to Orleans, where he got his play represented with great applause; but he soon became sensible of the faults of his work, and abandoned a species of composition in which he found he was not destined to excel. He soon afterwards went to England. Before leaving France, he accidentally became acquainted with Miss Pitt, sister to the Earl of Chatham, who gave him a letter to her brother; but after a short stay in London he returned to France. Not long afterwards, he was recalled to London by one of his uncles, to accompany a young English nobleman on his travels. Soon after his arrival, the young nobleman changed his intention; but, at the same time, he procured for Dutens the situation of a tutor in a private family. The father of the pupil was a man of considerable literary and scientific attainments, who instructed Dutens in those branches of knowledge in which he was deficient. In this manner he learnt Greek and mathematics; and he at the same time applied himself to the oriental languages, and to Italian and Spanish. At the end of three years his pupil died; but one of his sisters being deaf and dumb, her education was entrusted to Dutens. His young pupil, however, having become enamoured of his instructor, Dutens deemed it a matter of delicacy and of duty to leave the house.

About this time he was appointed chaplain and secretary to the Honourable Stuart Mackenzie, the English minister at the court of Turin, and left England in October 1758.

In 1760, when Mr Mackenzie returned to England, the secretary remained at Turin as chargé d'afaires. Dutens came to England in 1762, and attached himself to the family of Lord Bute, who, before retiring from office in 1763, procured him a pension. He again went to Turin as chargé d'afaires; and during this second mission he undertook the task of collecting and publishing a complete edition of the works of Leibnitz, and wrote his work on the Discoveries of the Ancients. He afterwards quitted Turin, returned to Britain, and attached himself to the Duke of Northumberland, who procured him a living in the north of England. He accompanied the duke's son, Lord Algernon Percy, in his travels through France, Italy, Germany, and Holland; and while at Paris he was chosen a member of the Academy of Inscriptions. In 1776 he returned to England, and soon afterwards accompanied Mr Mackenzie and his wife on a tour to Naples. On his return he was invited by Lord Mountstuart, who had been appointed envoy extraordinary, to accompany him to Turin; and Dutens found himself for the third time chargé d'afaires at that court, during a short absence of the envoy. From Turin, which he left on account of some unpleasant circumstances, he went to Florence, and thence to Rome. He was in Paris in 1783, and returned to London the following year. The revenue he derived from his living of Eldon, amounting to £500 per annum, together with a considerable legacy left him by Mr Mackenzie, and estimated at £15,000, enabled him to pass the remainder of his life in affluence. He died at London, May 23, 1812.

Duten was the editor of the works of Leibnitz, published at Geneva, 1769, in 6 vols. 4to; of the Greek pastoral romance of Daphnis and Chloe, by Longus, 1776, 12mo, and of Dacier's translation of the Manual of Epictetus, 1775, 18mo. He was also the author of the following works: La Copieuse Poétique, a collection of poems, 1760, 16mo. Recherches sur l'origine des Découvertes antiques aux Modernes, 2 vols. 8vo, 4th edition, 1812. Poésies, 1767, 12mo, and 1777, 8vo. Le Recueil, Rome, 1769, 12mo, reprinted under the title of Appel aux Sens, London, 1777, 8vo. This work was directed against the French philosophers, and was published anonymously. Explication de quelques figures de Peuples, de Ville et de Roy, Grands Plaques, 1773, 4to. Examen critique de quelques médailles du cabinet de Diane, 1774, 4to. Troisième Dissertation sur quelques médailles Grecques et Philippiennes, où se trouvent des observations, pour servir à l'étude de la Paléographie Numismatique, 1776, 8vo. Dutens at the same time published a more complete edition of the two preceding works. Logique, ou l'Art de Raisonner, 1773, 12mo, 1777, 8vo, and reprinted also in his miscellaneous works. Du mince ardent d'Archimède, 1775, 1777, 8vo; Des pierres précieuses et des pierres fines, avec les moyens de les connaître et de les évaluer, 1776, 12mo, and reprinted at London and Paris. Itinéraire des routes les plus fréquentées, ou Journal d'un Voyage sur les principaux Villages d'Europe, 1775, 8vo, frequently reprinted with additional important letters. Lettre à M. D. B. (Dutens) sur la réputation du Livre de l'Épargne, par J. J. Rousseau, 1779, 12mo, which contains some letters of Helvetius and Rousseau. De l'Église, du Pape, de quelques points de controverse, et moyens de réunion de tous les Églises Chrétiennes, 1781, 8vo; several times reprinted, and finally under the title of Considérations Théologiques sur les moyens de réunir toutes les Églises Chrétiennes, 1788, 8vo. Oeuvres mêlées, 1784, 8vo. Under the same title almost the whole works of Dutens were collected and published at London, 1797, 4 vols. 4to. L'Ami des étrangers qui voyagent en Angleterre, 1789, 8vo, frequently reprinted. Histoire de ce qui s'est passé pour la réconciliation d'une République en Amérique, 1789, 8vo. Recueillant le sens le plus récent de la langue Française des anciens, 1795, Mémoires d'un Voyageur qui se repose, Paris, 1808, 3 vols. 8vo. The first two volumes contain the life of the author, written in a romantic style; the third bears the title of Duttensiana, and is filled with remarks, anecdotes, bon-mots, and so forth. Dutens is the author of the Catalogue of Medals in Swinburne's Travels, and of the French text to the second volume of the Marlborough Gems. There is a Memoir of his in the Collection of the Academy of Inscriptions; and he also published a small tract on the Iron Mask. He was a member of the Royal Society of London, and had the title of historiographer to the king. (See Memoirs of Dutens in the Gentleman's Magazine for 1812; Chalmers's Biographical Dictionary; and Biographie Universelle.)