Venel, Gabriel François

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(b. Tourbes, near Pézenas, France, 23 August 1723; d. Montpellier, France, 29 October 1775),

chemistry, medicine.

The son of Étienne Venel, a physician, and Anne Hiché. Venel qualified as a doctor of medicine at the University of Montpellier in 1742. About 1746 he went to Paris to gain further experience in hospitals, and there he attended Guillaume–FranÇois Rouelle’s chemistry lectures and soon decided to devote himself to chemistry. He secured the patronage of Louis, duc d ’Orléans, who put him in charge of his laboratory at the Palais Royal, and he was appointed a royal censor for books on natural history, medicine, and chemistry.

Venel was interested in the composition of vegetable matter; in 1752 he compared fire analysis with the recently introduced method of solvent extraction, praising the latter and saying that it showed some principles–extract and resin, for example–to be common to the entire vegetable kingdom, whereas others, including essential oils and gums, were constituents of only certain plants. He never achieved his aim of examining each principle separately, for his attention was diverted to the analysis of mineral waters.

In 1750 Venel described his analysis of the effervescent mineral water of Selz, in Germany. Evaporation yielded only common salt and a little lime, and he was more interested in the effervescence, which was, he thought, caused by the escape of common air. All water contained a small amount of dissolved air, but Selzer and other effervescent waters contained superabundant air, as Venel called it. He made artificial Selzer water by adding the correct amounts of marine (hydrochloric) acid and soda to pure water, and he called the product aerated water, a term that is still in use. Stephen Hales had thought that effervescent mineral waters contained “sulphurous spirit"; Venel’s experiments proved the absence of the gas now called sulfur dioxide, but he failed to notice that the “superabundant air” differed in any way from common air. It was, of course, carbon dioxide, characterized in 1754 by Joseph Black, who called it fixed air. Fourcroy later commented that no one had ever been so close to making a discovery without actually making it as was Venel.1

The government wanted a report on all French mineral waters, and in 1753 Venel and Pierre Bayen were appointed to prepare it. They traveled widely, but when the Seven Years’ War started in 1756, Bayen became an army pharmacist2 and there were insufficient funds for Venel to continue alone.

While living in Paris, Venel met Diderot, one of the editors of the Encyclopédie. Most chemical articles in the first two volumes were by Paul–Jacques Malouin, but Venel contributed a few to the second volume (1751), and then became the principal author on chemistry and materia medica. Venel, who was unknown outside a small Parisian circle, was a strange choice as successor to so distinguished an academician as Malouin, but he rose to the occasion and wrote more than 700 articles in volumes three to seventeen (1753-1765). Many were short accounts of preparations, properrties, and medicinal uses of substances, but in some articles, including “Menstrue,” “Mixte,” and “Principes,” he expounded his ideas on the nature of matter–ideas that were based on an extensive and critical reading of recent chemical literature. He followed Hales in regarding air as a common constituent of solids, and he generally approved of Stahl’s phlogiston theory, but, curiously, he wrote no article on “Phlogistique” (although cross–references were given to such an article), perhaps because of his uncertainty about the properties of phlogiston.

In his longest article, “Chymie,” Venel criticized the Newtoians who saw chemistry merely as a branch of physics. The chemist was concerned with relationships between corpuscles and principles, and these were not necessarily subject to the same forces as the large masses studied by physicists. Even though they lacked mathematical precision, chemical theories could be as valid as physical laws, but Venel admitted that chemistry had not yet progressed as far as physics and that it awaited a “new Paracelsus” who would bring about a revolution in his subject.

Upon returning to the Languedoc, his native province, in 1758, Venel was elected to the Société Royale des Sciences de Montpellier; in 1759 he became a professor at the University of Montpellier, where he gave an annual course on materia medica. He recognized two classes of medicament—external and internal—with a further division into those that acted mechanically (including external ligatures or metallic mercury taken internally) and those that affected the body chemically. He admitted that there was not yet a satisfactory theory of the chemical action of medicaments, so the physician had to rely largely on observation.

Each year Venel gave a chemistry course, but this was outside the university, in the laboratory of Jacques Montet, who provided the accompanying demonstrations.3 In sixty–four lectures Venel gave a comprehensive account of the vegetable, animal, and mineral kingdoms, treating them in the same order as Rouelle. He did not discuss chemical theories in depth, but he expressed an opinion about phlogiston, which, he believed, did not gravitate toward the center of the earth but, on the contrary, levitated and thus diminished the weight of anything containing it. 4 Its release from a metal during calcination, therefore, caused the observed increase in weight. This theory was compatible with Venel’s belief that principles did not necessarily behave like large masses, but he never published it and, according to Bayen, did not hold it strongly.5 By the end of his life Venel had doubts about the whole doctrine of phlogiston, writing in 1775 that it was “beginning to age a little."6

Direrot said that Venel “vegetated” in Languedoc.7 Certainly he lived a comfortable bachelor life and cultivated his tastes for good food, wine, and conversation, but he was not idle between lecture courses, for he carried out agricultural experiments on his estate near Pézens and he became interested in other practical matters.

Wood was scare in Languedoc and at the request of the provincial government Venel wrote in 1775 a long treatise on the advantages of coal, which was abundant there. He recommended it for domestic use and also for local industries, including the manufacture of silk and olive oil (both of which required much boiling water) and the distillation of alcohol. He also resumed his work on mineral waters in 1773, and by 1775 had visited all the remaining French provinces, but he died before completing his book on the subject. This book, like other work done in his later years, remained unpublished. Fourcroy wrote a fitting epitaph: “Venel was better known by what he promised the sciences than by what he really did for them.”8


1. Antoine François de Fourcroy, Encyclopédie méthodique, chime . . ., III (Paris, 1796), 364.

2. Bayen was attached to the French expedition to Minorca in March 1756, and became chief pharmacist to the army in Germany in October 1756. See A. Balland, Les pharmaciens militaires français (Paris, 1913), 35–36, 39.

3. Jacques Montet (1722–1782), a pharmacist who had attended Rouelle’s chemistry lectures, was a leading member of the Société Royale des Sciences de Montpellier. See J. Poitevin, “Éloge de M. Montet,” in R. N. D. Desgenettes. ed., Éloges des académiciens de Montpellier (Paris, 1811). 242–249.

4. “Cours de chymie fait, chez Monsieur Montet apoticaire; par Monsieur Venel,” in the library of the Wellcome Institute for the History of Medicine, London, MS 1516, p. 164.

5. P. Bayen,Observations sur la physique . . .,3 (1774). 282.

6. G. F. Venel, Instructions sur l’usage de la houille (Avignon–Lyons, 1775), 495–496.

7. D. Diderot, “Voyage à Bourbonne et à Langers,” in Oeuvres complètes, R. Lewinter, ed., VIII (Paris, 1971), 600–627 (quotation from p.606).

8. Fourcroy, op, cit., 262.


1. Original Works. Before graduating from Montpellier, Venel defended a thesis, Disseratio de humorum crassitudine (Montpellier, 1741). When applying for the vacant chair in 1759 he wrote Quaestiones chemicae duodecim (Montpellier, 1759), twelve essays on medicochemical topics that were judged better than similar collections submitted by the other candidates.

Venel’s account of seltzer water was published in two parts, as “Méemoire sur l’analyse des eaux de Selters ou de Selz. Première (Seconde) Parite,” in Mémories de mathématique et de physique, présentés à l’Académie Royale des Sciences, par divers Savans2 (1755), 53–79, 80–112; his first (and only) paper on vegetable analysis is “Essai sur l’analyse des végétaux. Premier mémoire,” ibid., 319–332. An abridged version of the work on seltzer water appeared in one of the rare early issues of Observations sur la physique . . . (August 1772), 60–71; it was reprinted in Introduction aux observations sur la physique . . .,2 (1777), 331–334. Venel’s pnly other publication on mineral waters is a pamphlet, written with P. Bayen, Examen chimique d’une eau minérale nouvellement découverte ã Passy dans la maison de Monsieur et de Madame de Calsabigi (1755); repr. with other descriptions of the same water in the anonymously edited Analyses chimiques des nouvelles eaux minérales, vitrioliques, ferrugineuses, découvertes ã Passy dans la maison de Madame de Calsabigi (1757), 19–52.

More than 700 articles by Venel appeared in Diderot’s Encyclopédie, from II (1751) to XVII (1765), and he contributed two articles to the Supplement, I (1776). These are listed in R. N. Schwab, W. E. Rex, and J. Lough, “Inventory of Diderot’s Encyclopédie,” in Studies on Voltaire and the Eighteenth Century, LXXX (1971), LXXXIII (1971), LXXXV (1972), XCI–XCII (1972), with an author index in XCIII (1972). The important article “Chymie” in Encyclopédie, III (Paris, 1753), 408–437, was reprinted by A. F. Fourcroy, Encyclopédie méthodique, chimie, III (Paris, 1796), 262–303; a substantial extract (omitting Venel’s account of the history of chemistry) is in J. Proust, L’encyclopédisme dans le Bas–Languedoc au XVIIIe siècle (Montpellier, 1968), 106–140.

The last work by Venel to appear in his lifetime was Instructions sur l’usage de la houille, plus connue sous le nom impropre de charbon de terre . . . (A vignon-Lyons, 1775). His course on materia medica was published posthumously as Précis de matiére médicale, 2 vols. (Paris, 1787), with many notes and additions by Joseph Barthélemy Carrére. Students’ MS notes of Venel’s courses on materia medica and chemistry are in the libraries of the University of Montpillier, MSS 563–564; and the Wellcome Institute for the History of Medicine, London, MSS 1516–1517 (both courses, dated 1761) and MS 347 (materia medica, dated 1767).

II. Secondary Literature. Two valuable biographical accounts by men who knew Venel well are J. J. Menuret de Chambaud, Éloge historique de M. Venel . . . par M. J. J. M. (Grenoble–Paris, 1777); and E. H. de Ratte, “Éloge de M. Venel,” in Observations sur la physique . . ., 10 (1777), 3–14, repr. in J. B. Carrére’s edition of G. F. Venel, Précis de matiére médicale, I (Paris, 1787), vii–xxxviii, and also in R. N. D. Desgenettes, ed., Eloges des académiciens de Montpellier (Paris, 1811), 194–203.

Additional information is given by J. Castelnau, Mémoire historique et biographique sur l’ancienne Société Royale des Sciences de Montpellier (Montpellier, 1858), 74–76, 154.

Venel’s association with the Encyclopédie is discussed by J. Proust, L’encyclopédisme dans le BasLanguedoc au XVIIIe siécle (Montpellier, 1968), 23–27, 33–35. Venel’s theory of the levity of phlogiston is put in its historical context by J. R. Partington and D. McKie, “Historical studies in the phlogiston theory, I. The levity of phlogiston,” in Annals of Science, 2 (1937), 361–404. Venel’s criticism of Newtonian chemistry is discussed by Arnold Thackray, Atoms and Powers (Cambridge, Mass., 1970), 193–197.

W. A. Smeaton