THéVENOT, MELCHISéDECH

(b. Paris, France, 1620 or 1621; d. Issy [now Issy-les-Moulineaux], France, 29 October 1692)

scientific correspondence and translation, natural philosophy.

Thévenot was one of the important correspondents linking Paris to the rest of the European scientific world. He influenced the organization and founding of the French Academy of Sciences and was an intimate of Christiaan Huygens, Henry Oldenburg, Adrien Auzout, and numerous other mid-seventeenth-century personages. He was appointed keeper of the royal library in 1684 and admitted as a member of the Academy of Sciences in 1685.

Little is known of Thévenot’s personal life. After his formal education he traveled about Europe and made several voyages later in his life, including two diplomatic missions to Italy, but did not leave the Continent (“Thevenot’s voyages to the eastern Mediterranean and to northern Africa were those of his nephew Jean). Thévenot was a bibliophile and man of letters with a personal library of thousands of works, including a rich collection of books and manuscripts in foreign languages. One of the relatively few French scientists who read English, Thévenot also knew Greek, Latin, Hebrew, and several oriental languages, including Arabic and Turkish. His manuscript collection passed to the royal library in 1712.

Groups of savants and amateurs in mid-seventeenth-century Paris met Occasionally in private houses to discourse on philosophy and nature. From about 1654, and for a decade thereafter. Henri Louis Habert de Montmor held such meetings with enough regularity and sense of purpose that his group has been called the “Montmor Academy,” Thévenot attended Montmor’s meetings at least as early as 1658, and regularly for the next several years. Perhaps he began attending as early as 1655, for he met Huygens then, at a time when Huygens is known to have visited often with Montmor and with Pierre Gassendi, who was then living in Montmor’s house. Thévenot’s associates at the Montmor meetings included Auzout, Pierre Petit, Ismael Boulliau, Bernard Frenicle de Bessy. Jacques Rohault, and Girard Desargues, as well as most of the important scientific figures who passed through Paris. In these early years the Montmor Academy considered clocks and other mechanical devices, astronomical discoveries, questions of spontaneous generation and other biological matters, recent English and Italian studies on the void, and capillarity. These two latter phenomena especially interested Thévenot as early as 1658, and this interest contributed to his later development of a bubble level. Although there were those at the Montmor meetings, such as Thévenot, who emphasized experiment and observation, other members preferred rhetoric to experiment and the Montmor Academy gained a reputation for disputation and displays of temper.

After about 1662, partly because of these squabbles, Thévenot provided occasions for additional meetings and experimentation in his country house at Issy, several miles south of Paris. There he supported the mathematician Frenicle de Bessy, the Danish anatomist Nils Stensen, and a chemical demonstrator. Also at Issy, Thévenot pursued his studies of the void and made various astronomical and magnetic studies, aided by Petit, Auzout, Frenicle de Bessy, and Huygens. Various problems, including the continuing bickering over the proper emphasis to be placed upon experiment, led to the demise of the Montmor Academy in 1664. Thévenot held his meetings for another year or so, but lack of sufficient funds for apparatus and experimentation hampered his work.

About this time efforts were made to reorganize the Montmor Academy. Samuel-Joseph Sorbière, its permanent secretary, approached the leading minister of Louis XIV, Jean-Baptiste Colbert, and presented him with the draft of a revised constitution and a letter asking for royal protection. At about the same time another plan was proposed for a new academy of scientists. The latter plan, a document of some twenty-six clauses and two thousand words, exists as an unsigned, undated manuscript.¹ Evidence indicates that the plan, entitled “Project de la compagnie des sciences et des arts,” was written about 1663 or 1664 by a group that included Thévenot, Auzout, and Petit. The proposed compagnie would perform experiments and make observations to disabuse the world of its “vulgar errors,” seek to invent new machines, work especially at discovering the causes of ill health, make lists and tables of practical arts and machines, seek to improve navigation and commerce publish the memoirs of those who voyaged to foreign lands, and write a universal natural history. It would be composed of

. . . the most knowledgeable in all the true sciences that one can find, as in geometry, in mechanics, optics, astronomy, geography &c., in physics, medicine, chemistry, anatomy, &c., or in the applied arts, as architecture, fortifications, sculpture, painting, and design, the conduct and elevation of waters [hydraulics], metallurgy, agriculture, navigation &c.,²

Religion and politics would be excluded. This Baconian program promised to form the compagnie for the “perfection of the sciences and the arts and, in general, to search for all that can bring utility or convenience to the human race, and particularly to France.”³ Thévenot’s utilitarian project for a compagine des sciences et des arts was quite different from one proposed by Charles Perrault, who envisioned an academy that was less practical and more philosophical and cultural, the pure sciences being allied with bells letters rather than with engineering.

The Academy of Sciences that emerged in 1666 was more in Perrault’s design than in Thévenot’s. The amateurs among the Montmor group, including Thévenot, were not members of the new academy. Brown implies that Thévenot, as a amateur, was omitted from consideration.⁴ Maury claims that Thévenot, although the “father” of the new academy, was not included among the original members because of “infirmities” that kept him at Issy.⁵ This does not accord with the Éloge in the Journal des sçavans, evidently written by a personal friend (possibly Jean Gallois), which states that Thévenot, “being of a robust constituion, . . . enjoyed excellent health” until the month of his death, when, attacked by a fever, he initiated a continuing fast that served further to weaken his health and brought on his death. Recent evidence published by McKeon quotes Thévenot, in a letter to Prince Leopold, as saying he had been invited to become a member.⁶ In any case, Thévenot finally became a member of the Academy of Sciences in 1685, filling the place of Pierre de Carcavi, who had died in 1684.

Throughout the 1660’s and 1670’s Thévenot maintained a wide correspondence with numerous persons. Much of it related to his celebrated translation and publication of voyages of discovery, Relations de divers voyages . . .. His only notable direct contribution to science was in instrumentation: a bubble level, later improved by Robert Hooke and by Huygens. Thévenot’s work on the level was probably connected with his experiments on capillarity and the siphon, undertaken in 1658–1661. He mentioned his level in 1661 and 1662 in letters to Vincenzo Viviani and to Huygens, and it was publicized in an unsigned pamphlet in 1666.⁷ Thévenot’s original design probably began to evolve in 1661 and was publicly mentioned at various times between 1666 and 1681, when he described it in his essay “Discours sur l’art de la navigation,” published in his Recueil de voyages . . .. The original bubble level seemed to lack convexity in the glass tube, a fact remarked upon by Huygens.

Thévenot described and illustrated his level in 1681, still without discussing convexity in the tube, although he did mention the possibility of utilizing Auzout’s idea of metal cross hairs with a lens for accurate measurement. The level tube, he said, was about the diameter of one’s little finger and its length was seven or eight times its diameter. The level was filled with alcohol and mounted on a stone ruler fitted with a viewing lens. Glass fabrication methods made it difficult to obtain tubes of constant cross section, and Thévenot’s design initially was used by others simply to align a plane surface parallelto the horizon. Thevenot’s claims that his level would be useful in finding magnetic declination at sea and determining a plane parallel to the horizon at sea seem rather exaggerated. Daumas states that Thévenot’s design did not come into common use until the mideighteenth century with the development of improved construction techniques.⁸

One other incident made Thévenot a subject of discussion in the scientific salons: his presentation and development of a theory concerning the cause of human and animal respiration. Sometime during 1660 an unnamed person at the Montmor Academy had suggested that a constant atmospheric pulsation caused the “movements of the heart, of the punctum saliens of the egg, that of the brain, the diaphragm, or of respiration.”⁹ Thévenot said that the idea, if not true, at least had some merit; and he proceeded to attempt to demonstrate the atmospheric pulsation experimentally. He claimed that if one put water into a flask with a capillary neck and then tipped the flask so that the water filled part of the neck, one could observe the water pulsating in sympathy with the atmospheric pulsation. After a slight warming, one could observe the “diastolic and systolic [motions] with all the circumstances that one finds in the parts of animals that have this movement,” the rate of motion depending on the amount of heat applied.¹⁰

Thévenot spread this news through Oldenburg and Huygens, and it was widely discussed for a time. This incident is quite typical of the sort of experiment performed and the type of tales told in seventeenth-century science, and Thévenot is not to be imagined a fool. His scientific contributions, however, should be seen as limited to his general encouragement of scientific enterprise through his letters, his personal efforts, and his published translations. In the period after 1685, when he was a member of the Academy of Sciences, he occasionally discussed items at its meetings: for example, a buffalo-like creature in North America, lemon juice as a medicinal cure, the excision and subsequent regeneration of a lizard’s tail, and ipecac as useful in treating dysentery.

NOTES

1. See Huygens, Oeuvres complètes,IV, 325–329, for the text of this document.

2.Ibid., 328.

3.Ibid., 325.

4. Harcourt Brown, Scientific Organizations . . ., 117.

5. L-F. A. Maury, L’ancienne AcadÉmie des sciences, 12–13.

6. McKeon, “Une lettre de MelchisÉdech Thévenot . . .,” 2–3.

7. Huygens, Oeuvres complètes,XXI, 105–108, presents Huygens’ description of Thévenot’s level.

8. Maurice Daumas. Les instruments scientifiques aux XVII^e et XVIII^e siècles, 77.

9. Thévenot to Huygens, in Huygens, Oeuvres complètes,III, 405.

10.Ibid., 406.

BIBLIOGRAPHY

I. Original Works. Consult the Catalogue gÉnÉral des livres imprimÉs de la Bibliothèque nationale,CLXXXVI, or Michaud’s Biographie universelle, 2nd ed., XLI, for detailed listing of Thévenot’s works. Discussions of the publishing history of Thévenot’s Voyages appear in Armand Gaston Camus, MÉmoire sur la collection des grands et petits voyages . . . (Paris, 1802), 279 ff.; and James Lenox, The Voyages of Thévenot (New York, 1879).

Thévenot’s most famous work was his collection of translations of voyages of discovery, Relations de divers voyages curieux . . .,4 vols. (Paris, 1663–1672); and a small supplement, Recueil de voyages de M^r Thévenot (Paris, 1681). The latter contains Thévenot’s description of his level in “Discours sur l’art de la navigation.” The Catalogue de la bibliothèque de Thévenot (Paris, 1694) contains a short autobiographical preface by Thévenot. (I have not examined the latter work.) Drawing on previous books by Everard Digby the elder and by Nicholas Winman, Thévenot wrote a primer on swimming that was published after his death as L’art de nager (Paris, 1696) and went through numerous illustrated French and English eds. over the next century.

Coincident with his interests in hydrostatics and mechanics, Thévenot began an ed. of works by Hero and others but died during the preparation. The task was completed by Jean Boivin and Philippe de la Hire: Veterum mathematicorum, Athenaei, Bitonis, Apollodori, Heronis, Philonis et aliorum opera . . . (Paris, 1693).

Letters written by and concerning Thévenot are in Christiaan Huygens, Oeuvres complètes, 22 vols. (The Hague, 1888–1950), III–VII. IX–X. XVII, XX, XXII: The Correspondence of Henry Oldenburg, edited and translated by A. Rupert Hall and Marie Boas Hall, (Madison, Wis., 1965– ), I–III, VI. Robert M. McKeon published a letter from Thévenot to Prince Leopold sur les dÉbuts de l’AcadÉmie royale des sciences,” in Revue d’histoire des sciences et de leurs applications,18 (1965), 1–6. On Thévenot’s influence on the founding of the Academy of Sciences, see also T. McClaughlin, “Une lettre de MelchisÉdech Thévenot,” in Revue d’histoire des sciences,27 (1974), 123–126. Harcourt Brown published an unsigned letter concerning Swammerdam’s investigations and properly attributes this to Thévenot in his Scientific Organizations in Seventeenth Century France(1620–1680) (Baltimore, 1934), 280–281. Thévenot’s comments and reports at the Academy of Sciences for the years 1685–1689 are mentioned in Histoire de l’AcadÉmie royale des sciences depuis 1666 jusqu’ à 1699,I, II (1733).

II. Secondary Literature. The best general introduction to scientific societies in Thévenot’s era, as well as to his career, is Brown, op cit. A contemporary Éloge of Thévenot is in Journal des sçavans,20 (17 Nov, 1672), 646–649 (pub. 1693). A brief biography is in Louis MorÉri, Le grand dictionnaire historique de MorÉri,X (Paris, 1759), 138–139. Subsequent biographical sketches of Thévenot add nothing to these. A brief history of the level and of the acceptance of Thévenot’ bubble level is in Maurice Daumas, Les instruments scientifiques aux XVII^e et XVIII^e siècles (Paris, 1953), 76–78. For additional discussion of this, see Gilbert Govi, “Recherches historiques sur l’invention du niveau à bulle d’air,” in Bullettino di bibliografia e di storia delle scienze matematiche e fisiche,3 (1870), 282–296. McKeon’s article (cited above) contains a discussion of events at the time of the founding of the Academy of Sciences in 1666; see also Brown, op cit.; Guillaume Bigourdan, “les premières sociÉtÉs savantes de Paris . . .,” in Comptes rendus . . . de l’AcadÉmie des sciences,163 (1916), 937–943; 164 (1917), 129–134, 159–162, 216–220–also published separately as a pamphlet (Paris, 1919). In addition, consult L.-F. Alfred Maury, L’ancienne AcadÉmie des sciences (Paris, 1864), 10–13, 31, 37–38; and Roger Hahn, The Anatomy of a Scientific Institution, the Paris Academy of Sciences, 1666–1803 (Berkeley, 1971), 6–8. For information concerning Thévenot and his interests in astronomy and scientific instrumentation, see Robert M. McKeon, “Établissement de l’astronomie de prÉcision et oeuvre d’Adrien Auzout” (unpub. diss., University of Paris, 1965).

C. Stewart Gillmor