PELLETIER, BERTRAND

(b.Bayonne, France, 31 July 1761; d. Paris, France, 21 July 1797),

chemistry.

The son of Bertrand Pelletier, a pharmacist, and Marie Sabatier, Pelletier was apprenticed to his father until 1778. He then continued his pharmaceutical training with Bernard Coubet in Paris, where he was befriended by Jean d’Arcet, an acquaintance of his father, and Pierre Bayen. In 1782 he became d’Arcet’s assistant and lecture demonstrator at the College de France, and soon published his first paper, an account of the preparation and properties of arsenic acid.

In 1783, on d’Arcet’s recommendation, H. M. Rouelle’s widow appointed Pelletier manager of her pharmacy in the rue Jacob. He qualified as a master pharmacist in 1784, the year of his marriage to Marguerite Sedillot, and then bought the Rouelle pharmacy (which is still called the Pharmacie Pelletier). Chemical investigations took up much of his time, however, so he assigned the management of the business to his elder brother, Charles, also a master pharmacist. From 1783 Pelletier was registered as a student in the Paris Faculty of Medicine, but he did not graduate there. In 1790, however, he made two journeys to Rheims, where he passed the examinations for his doctorate in medicine. The Paris Academie des Sciences elected Pelletier in 1792, the year before its suppression.

Pelletier was a skillful chemist, concerned more with experiment than with theory. He spent much time checking and extending the researches of others, and therefore made few original contributions to chemistry. His experimental skill was demonstrated in 1784, when, at the suggestion of the crystallographer J.-B. Romé de l’lsle, he prepared crystals of several very soluble or deliquescent salts by using the techniques of slow evaporation and seeding. In 1785 he confirmed C. W. Scheele’s discovery that the gas now called chlorine is obtained from the reaction between marine (hydrochloric) acid and manganese clax (dioxide) and, independently of C. L. Brethollet, he came to the incorrect conclusion that it was a compound of marine acid and oxygen. But unlike Berthollet, Pelletier did not yet accept Lavoisier’s antiphlogistic theory; and he followed Scheele in describing chlorine as “dephlogisticated marine acid”, even though he thought it was a compound containing marine acid. By the action of chlorine on alcohal Pelletier obtained a product that he regarded as marine ether (ethyl chloride,) but it must have been chloral. He considered other “ethers”— sulfuric (diethyl ether), nitrous (ethyl nitrite or nitrate,) and acetous (ethyl acetate)—-to be formed by the action on alcohol of the dephlogisticated air present in the various acids. He continued to call oxygen “dephlogisticated air” until late in 1787; and it seems that, like his mentor d’Arcet, he accepted Lavoisier’s theory and the new nomenclature only after some hesitation.

Pelletier’s important series of researches on phosphorus (1785–1792) included the preparation, for the first time, of the phosphides, of most metals. The slow oxidation of phosphorus over water yielded an acid that he thought was phosphorus acid, but he did not complete his examination of its salts; in 1816 P. L. Dulong showed that it was in fact hypophosphoric acid.

Copper was scarce during the French Revolution, and in 1790 Pelletier devised a process for recovering it from bell metal (an alloy of copper and tin) by oxidation with manganese dioxide, which attacked the tin before the copper; a good yield was obtained, but A. F. Fourcroy’s method of atmospheric oxidation proved to be cheaper and was generally preferred. Pelletier became a member of the Bureau de Consultaion des Arts et Metiers and of the Commission Temporaire des Arts, and for both organizations he helped to prepare reports on crafts and industries of national importance. The best-known of these was the report recommending Nicolas Leblanc and Michel-Jean Dize’s process for soda manufacture; but Pelletier also contributed to reports on M. E. Janety’s malleable platinum, Armand Seguin’s method for tanning leather, the production of soap, and the repulping of waste paper.

Pelletier was appointed assistant professor when the École Polytechnique opened in 1794, and he helped Guyton de Morveau with the course on mineral chemistry. In 1795 he was elected to the Institut de France. He served on a commission of the Institut that investigated methods of refining and analyzing saltpeter for gunpowder manufacture, but he was already suffering from pulmonary tuberculosis and died before the work was finished.

BIBLIOGRAPHY

I. Original Works. Most of Pelletier’s publications are listed in Poggendorff, II, col. 392. His reports on the extraction of copper from bell metal, the manufacture of soda, and the production of soap were written jointly with Jean d’Arcet and others; details are given in the bibliography of d’Arcet, in Dictionary of Scientific Biography, III, 561. These and other reports were reprinted with all of Pelletier’s scientific articles in a collected ed. published by his brother Charles Pelletier and his brother-in-law Jean Sedillot, as Memoires et observations de chimie de Bertrand Pelletier, 2 vols. (Paris, 1798). As a member of various commissions of the Institut de France, Pelletier contributed to several reports that were eventually published in Proces-verbaux des seances de l’Academie [des Sciences,] I (Hendaye, 1910) 32–33 (examination of some minerals with d’Arcet and Claude Lelievre); 71–75 (analysis of an alloy, with P. Bayen et al); 228–230 (report on a memoir by N. Deyeux, with L. B. Guyton de Morveau et al); 244–256 (report on the refining and analysis of salpeter, with Guyton et al.).

In 1792 Pelletier joined the editorial board of Annales de chimie, he was also a coeditor of the short-lived Journal d’histoire naturelle, which was founded by Lamarck and others in 1792 and ceased publication in the same year.

II. Secondary Literature. See Sédillot, Éloge, de B. Pelletier,” in Mémories et observations de chimie de Bertrand Pelletier, I (Paris, 1798), vii–xxvii. Further information, including the correct date of birth, is given by P. Dorveaux, “Bertrand Pelletier,” in Revue d’histoire de la pharmacie, 6 (1937), 5–24.

W. A. Smeaton