(b. Vatan, France, 6 January 1645; d. Paris, France, 3 November 1722)
anatomy, surgery, pathology.
Intent on following in his father’s profession, Méry traveled to Paris at the age of eighteen to study surgery at the Hôtel-Dieu, then the best place to learn surgical practice. In addition to his regular studies, Méry undertook clandestine dissections whenever fresh human material became available to him. After completing his preparations he set up a private surgical practice, becoming well known, particularly in lithotomy. Much of his career was centered at the Hôtel-Dieu, where he was surgeon from 1681 and chief surgeon from 1700. He was appointed a senior surgeon at Les Invalides, Paris, in 1683. In 1684 Méry was elected to the Academy of Sciences. He also had connections with the French court. In 1681 he was appointed surgeon to the queen and later was sent by the court on at least two medical missions. Méry traveled to England in 1692 for the court, but the purpose of this trip is unknown.
Méry tended to be taciturn, has been described as argumentative, and often saw his family only at meals. He did a thorough job at the Hôtel-Dieu, both in his hospital practice and in training young surgeons. The balance of his time was divided between the Academy and his anatomical research.
Most of Méry’s researches were comparative-anatomical and pathological. The pathological researches were mostly descriptive in character and covered a wide range of situations, although most of them were concerned with human developmental malformations. Of greater interest are his researches in comparative anatomy, including his physiological investigations. In the latter his methods were comparative and were based on preserved and dried anatomical specimens. Because of the limited preservation techniques available, this approach could be deceptive.
After his election to the Academy in 1684, Méry became closely associated with the comparative-anatomical work led by Claude Perrault and J.-G. Duverney. As a member of this group, Méry made contributions to their joint publications, in which each man’s specific contributions usually cannot be determined. Méry worked closely with Duverney until about 1693, when their differing interpretations of mammalian fetal circulation estranged them. The coolness that resulted was apparent to Martin Lister, when he visited Paris in 1698. Méry probably did more to retard than to aid the understanding of this problem. Méry claimed that the blood flowed from the left to the right through the foramen ovale in the interatrial septum. This view was prevalent enough that Haller look time to refute it. Méry initially formulated his theory from a false analogy between a tortoise heart and a fetal mammalian heart. Ultimately he based his theory of fetal circulation on a comparison of the cross sections of the pulmonary artery and the aorta, concluding that not all of the blood passing through the pulmonary artery and returning to the heart by the pulmonary vein could pass into the aorta. Instead, he thought, a portion of that blood passed through the foramen ovale from the left to the right side of the heart.
Méry erred in assuming that the cross section of an artery is the only factor determining the amount of blood that can flow through it. He compounded this error by his method of measuring the relative cross sections of the arteries. He may have used fresh preparations for his measurements on cows and sheep. For those on human beings, he probably used preserved specimens, dried ones as a rule. The results were inconsistent at best. For example, Martin Lister described a fetal heart that he saw in Méry’s collection which had no valve for the foramen ovale, and which was open in both directions and had a diameter nearly equal to that of the aorta. For two decades numerous arguments were presented on both sides of the controversy between Méry’s views and the traditional views dating back to Harvey and Lower. Méry held his views against all opposition to the end.
In other areas of anatomy Méry demonstrated that he was a capable and careful worker, making a number of valuable contributions to the anatomy of a wide range of animals. He described the urethral glands named after Cowper some years before Cowper’s description, and he preceded Winslow in a description of the eustachian valve, although he misinterpreted its function as part of his concept of the mammalian fetal circulation.
I. Original Works. For a list of Méry’s anatomical studies in Mémoires de l’Académie royale des sciences, see either the 1734 index volumes or J. D. Reuss, Repertorium commentationum … a societatibus litterariis editorum, 16 vols. (Gottingen, 1801–1820). Much of the controversy on fetal circulation is contained in Nouveau systéme de la circulation du sang par le trou ovale dans le foetus humain; avec les réponses aux objections de Messieurs Duverney, Tauvri, Verheyen, Silvestre & Buissiere contre cette hypothése (Paris, 1700), as well as scattered papers. He made unidentified contributions which were incorporated in Mémoires pour servir à l’histoire naturelle des animaux (Paris, 1732–1734).
II. Secondary Literature. Principal biographical sources are the article in Biographie universelle ancienne et moderne, XXVIII (Paris); Bernard Le Bouyer de Fontenelle, “éloge,” in Oeuvers de M. de Fontenelle, VI (Amsterdam, 1754); and Martin Lister, A Journey to Paris in the Year 1698 (London, 1699), passim. There are numerous references to Méry throughout the appropriate years of the Histoire de l’Académie royale des sciences. For Méry’s theory of fetal circulation see Kenneth J. Franklin, “Jean Méry (1645–1722) and His Ideas on the Foetal Blood Flow,” in Annals of Science, 5 (1945), 203–338; and for some of his other anatomical work see F. J. Cole, A History of Comparative Anatomy from Aristotle to the Eighteenth Century (London, 1944).
Wesley C. Williams