Sage, Balthazar-Georges

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(b. Paris, France 7 May 1740; d. Paris, 9 September 1824)

metallurgy, assaying chemistry.

Except as founder of the Paris Éole des Mines, there is little reason to rate Sage as an important scientific figure. He published extensively, often hurriedly, and—toward the dismal end of his life—usually for self-serving purposes. The chief modern study of Sage describes his scientific work as totally without value.1 Another historian has called him a “faux savant.” 2 Partington, on the whole, is somewhat more charitable.3

The younger son of a Paris pharmacist of limited means (who was the son of a notary of St.-Jean-de-Maurienne in Savoy named Sapienti), Sage was sent as a day student to the famous Collége des Quatre Nations.4 His interest aroused in science, he became an accredited pharmacist and attended the public lectures of G. F. Abbé Nollet and the chemical lectures of G. F. Rouelle, whose experiments he repeated in a small laboratory he was able to equip. In 1760 Sage opened at the family pharmacy a public course of lectures in chemistry and the techniques of assaying. Here, too, he housed the beginnings of an extensive mineralogical collection. In 1769 he published his first work, Examen chymique de différentes substances minérales.5

Skilled at finding and bemusing powerful patrons, Sage made connections at court and obtained the direct support of Louis XV, who put pressure on the Academy of Sciences (even sending his orders by special courier) to admit Sage, even if it meant installing him above the lowest rank.6 The Academy evidently compromised, for it elected Sage in 1770 but ranked and promoted him according to its established procedures. At the death of Rouelle in that year, Sage replaced Cadet de Gassicourt as adjoint. when Cadet was promoted to associé. In 1777 Cadet became prensionnaire, and Sage succeeded him as associé.7

Sage’s dubious qualifications as a chemist were soon evident. In his Examen chymique and his more successful élémens de minéralogie docimastique (1772), Sage had claimed that a white lead ore found at the famous mine of Poullaouen in Brittany was a compound of lead and marine acid (hydrochloric acid). even asserting in the latter book that the ore contained twenty percent by weight of marine acid. Late in 1772 a master apothecary of Paris, one Laborie, reported to the Academy of Sciences an analysis of this ore which controverted Sage’s results; accordingly, a committee composed of the other chemists in the Academy carried out experiments in Baumé’s laboratory to decide between the contestants. They concluded unanimously that the ore contained no trace of marine acid.8 It is perhaps significant that while both Laborie and Sage were invited to observe the experiments, only Laborie accepted the invitation.

Yet in these early years Sage took an active part in the Academy’s proceedings, often joining other chemists, among them Lavoisier, on special investigating committees. In 1774, for example, Sage, Brisson, and Lavoisier demonstrated that the rival preparations of mercuric oxide (mercure précipité per se) by Baumé and Cadet were identical and— this was to play a part in the earliest preparation of oxygen gas in France—were reducible without the addition of substances supposed to contain phlogiston.9 In 1778 Sage joined Macquer and Lavoisier in analyzing a sample of water from the Dead Sea.10 He also was appointed one of the commissioners to award a prize in 1778 for the best method of increasing the production of saltpeter in the kingdom: and, with Macquer, Lavoisier, Baumé, and d’sArcy, he helped assemble the Recueil de mémoires et d’observations sur la formation & sur la fabrication du salpêtre (1776).11 Later he contributed rare mineral specimens and precious stones from his collection for Lavoisier’s experiments on the effect of intense heat produced by combustion with oxygen.12

The verdict on Sage as a chemist is almost universally negative. Partington, to be sure, ascribes to him a small number of minor chemical discoveries: the preparation, independently of Guyton de Morveau, of solid potassium ferrocyanide; the discovery of hypophosphoric acid; the demonstration (1776) that silver chloride can be reduced by iron and that phosphorus can reduce metallic salts to metals.13

If Lavoisier often cited Sage, it was not infrequently to correct his manifest errors. Perhaps the most notorious of Sage’s stubborn mistakes was his report that he had obtained substantial amounts of gold from ashes. Others were unable to duplicate his results. The chemists of the Academy carried out a careful analysis and found that the amount of gold was not only infinitely small, but was derived from the minium used in treating the ashes.14 Polemics on this matter shook the Academy, taking on the dimensions of a scandal. Indeed, according to one observer, censure of Sage by his colleagues was avoided only by personal antagonisms within the Academy.15

Most contemporaries viewed Sage as a successful teacher, esteemed by his students, but as a very poor chemist. This judgment was common well before he expressed his opposition to Lavoisier’s new chemistry. In 1772 Turgot wrote to Condorcet that it was foolishness (sottise) for the Academy to have passed over the younger Rouelle and Jean Darcet and to elect Sage.16 On 28 March 1775, Macquer—the dean of French chemists—wrote to Bergman that Sage

... totally lacks a gift for chemistry [n’a point du tout l’espirit de la chimie] and does not understand that science at all. This is what makes him so bold in making hasty inferences from the slightest evidence [les moindres apparences]. In the end, he will seriously damage himself with the real chemists. But since he has as much confidence as he has little knowledge, many people who know no more than he, think of him as a remarkable discoverer, and these are highly-placed persons [grands personnages] and very numerous.17

A recent history of chemical mineralogy has little to say on Sage’s behalf, describing his analytical technique as “most unsatisfactory” except when he was using traditional methods in assaying metalic ores. Because of his peculiar theories “he became hopelessly entangled whenever he attempted to use ‘wet’ methods of analysis.” 18 In the light of his dubious competence and Macquer’s opinion of him, it is ironic that Sage was promoted to pensionnaire in the Academy upon the latter’s death in 1784.

Two years after his promotion Sage’s Analyse chimique et concordance des trois règnes was published (1786). Fulsomely dedicated to Louis XVI, to whom he owed “tout ce que je suis,” Sage described it as the result of twenty-five years of work. Here, as well as in his Mémoires historiques et physiques (1817), he set forth the doctrine that formed the basis of his teaching. Sage could not deny the experimental demonstration by his contemporaries that air is a mixture of gases. Yet he continued to believe not only in the reality of phlogiston but also in what he called l’acide igné, a substance imagined to be “the essence of the different aeriform fluids.” 19 From the union of this acid with phlogiston arose the different sorts of air, notably oxygen, as well as electricity, oils, and the “principle” of metallicity. Acids were derived from this acide igné élémentaire, which was combined in compound bodies (corps organisés) with different amounts of phlogiston, earth, and water. In his Analyse chimique Sage noted that two celebrated scientists (Lavoisier and Laplace) had advanced the view that water is composed of inflammable air (hydrogen) and dephlogisticated air (oxygen). A series of ingenious experiments seemed to support their theory, but to Sage such experiments merely proved that water is one of the constituents of the different sorts of aeriform fluids.20

In 1787 there appeared, with the sanction of the Academy of Sciences, the famous Nomenclature chimique, the work of Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy. To appraise this work, the Academy appointed a committee consisting of Baumé. Cadet de Gassicourt, Darcet, and Sage. The rapporteurs recognized without hesitation that a new theory of chemistry was implicitly being arrayed against the old.21 They gave high praise to the authors of this radical work, pointed out some of its advantages, and raised certain doubts (about, among other matters, the conclusions drawn from the synthesis of water). Not only was it difficult, they wrote, to abandon all the principles of one’s chemical education, but it was even more difficult suddenly to admit that a host of substances, which analogy suggested must be compound, should henceforth be regarded as simple substances. And they concluded:

We therefore believe that one must submit this new theory, as well as its nomenclature, to the test of time, to the impact of experiments, to the consequent weighing of opinions; finally to the judgment of the public as the only tribunal by which it ought or can be judged.22

Although Sage’s opposition was muted by the views of his more discreet coauthors, he never abandoned his idiosyncratic position. As late as 1810 he expressed his disapproval of the new chemistry and the new nomenclature by publishing his Exposé des effets de la contagion nomenclative et réfutation des paradoxes qui dénaturent la physique. When Sage published his Mémoires historiques et physiques in 1817 he still praised the old theory of Johann Friedrich Meyer and rejected Joseph Black’s demonstration of some sixty years earlier that chalk is composed of quicklime and “fixed air” (carbon dioxide). Instead, Sage wrote, terre calcaire (calcium carbonate) is a salt composed of his cherished acide igné (obviously a descendant of Meyer’s acidum pingue) with a specific earth, some oleaginous matter, and water. Yet, he continued, Black’s erroneous theory (he described Black as a chimiste anglais!) had been adopted by the “secte lavoisienne” as if it were a demonstrated truth.23

The creation of the Paris École des Mines is Sage’s major claim to distinction. The idea of such a school had first occurred to Daniel Trudaine, the intendant des finances who had founded in 1747 the École des Ponts et Chaussées. Yet it did not seem feasible at that time, in view of the primitive state of the French mining industry, to establish a parallel school of mines. Instead, on the advice of Jean Hellot, chief assayer at the mint, Trudaine reserved a few places at the Ponts et Chaussées for young persons recommended by the directors and owners of mines. Their professional instruction was to be completed by a course in chemistry and practical experience at one of the better-managed mines. In this fashion were trained the earliest inspectors and advisors to the mining industry, notably Gabriel Jars and J. P. F. Guillot-Duhamel (1730–1816).24

The first steps toward the creation of the École des Mines were taken under the auspices of Henri-Léonard-Jean-Baptiste Bertin. A protégé of Mme de Pompadour, he had served as contrôleur-général des finances from 1759 to 1763. On leaving that office, he retained the title of minister and secretary of state and put together a catch-all department, responsible for several diverse activities. Among these, and of particular interest to him, were the mines of France.25

Soon after taking over his new post, Bertin received memoirs proposing the creation of two schools of mines in the provinces. Consulted by Bertin, Antoine Monnet, recently appointed to the post of inspector general of mines, strongly opposed this suggestion and urged instead that courses in mineralogy and metallurgy be established at the Jardin des Plantes and that students, after being examined on these subjects (as well as on chemistry and mathematics), should complete their training at one of the better-run mines. Soon after, Monnet’s colleague Jourdan, together with Sage, who then held the post of supervisor of assaying at the mint, urged Bertin to create a school of mines at Paris, to be supported by a tax levied on the mine owners. Monnet opposed this project with enthusiasm enhanced by his dislike of Sage.26

Yet Sage gained at least a partial victory. By letters patent of 11 June 1778 a chair of mineralogy and docimastic metallurgy was established at the mint. Sage received the royal appointment with a stipend of 2,000 livers per annum and with Guillot-Duhamel as his assistant. He installed his already substantial collection of minerals in the great hall of the building recently taken over for the mint and completely redesigned by the architect Jacques-Denis Antoine (1733–1801). Here Sage taught mineralogy, in what he later called his first École des Mines, to students among whom, we are told, were Chaptal (the future industrial chemist), the crystallographer Romé de l’Isle, and the surgeon Jean Demeste (1743–1783), who described Sage as the most distinguished chemist in France.27

When Bertin left the government in 1780, the special department was abolished and the Service des Mines was put under four intendants de commerce. On 21 May 1781 the supervisory administration for the mines was further modified by the creation of a special intendant for the mines, Douet de La Boullaye. Under Douet, despite the predictable opposition of Monnet, three decrees (arrêts) dated 19 March 1783 were issued, one of which established a full-fledged school of mines, modeled after the highly successful école des Ponts et Chaussées. After stressing the backwardness of France’s exploitation of its mineral resources and the difficulty of finding qualified personnel, this arrêt provided for the establishment of two professorships, one for mineralogy and assaying (la chimie docimastique) and the other for the practical aspects of mining (l’exploitation des mines). The school was to be located at the Hôtel de la Monnaie on the Quai de Conti; and the chair of mineralogy and assaying was filled by Sage, who was also to serve as director. The other professorship went to Guillot-Duhamel. Secondary posts were established for the teaching of mathematics (Prud’homme), drawing (Miché), and foreign languages (the Abbé Pierre-Romain Clouet). At least for a brief time Jean-Henri Hassenfratz, who in 1785 became a deputy inspector of mines, taught physics at the school, as did J. A. Charles.28 Lesser staff included a curator of the mineralogical cabinet, the core of which was Sage’s collection, ceded to the king in exchange for a lifetime annuity (rente viagère) of 5,000 livres.29

To be admitted to the École des Mines, a student had to be sixteen years old; the course of studies, in principle at least, lasted three years; and lectures were delivered from November to June. The number of students was never large: eight were admitted in 1783, and the entering class of 1786 numbered twenty-one. Of these, twelve were called élèves titulaires or stipendiés, for they received a government scholarship of 200 livres.30 No new students were admitted after 1787.

Sage served as director and professor for at least seven years. The audience for his lectures may have been substantial, since besides those registered in the École des Mines, students of the École des Ponts et Chaussées were expected to attend his lectures on chemistry and mineralogy. His teaching, if the content can be judged from his Analyse chimique des trois règnes, was probably not very scientific or profound. He taught mineralogy, remarked Aguillon, as a simple display of minerals and rocks distinguished by inadequate and superficial characters, with no trace of the classification made possible by recent advances in chemistry and by the new crystallography of Haüy, both of which he totally ignored.31

The school, although small, was elegantly housed in the mint. Sage records that he received a substantial gratuity from the king for having salvaged gold worth some 440,000 francs from gilded decorations (vieilles dorures), and had received permission to apply his gratification of 40,000 francs to decorating the school’s quarters according to the plans of the architect Antoine.32 With the onset of the Revolution, and the increasingly desperate state of French finances, this extravagance was held against Sage and the institution he had founded.

Reporting in 1790 for the finance committee of the Constituent Assembly, Charles-François Lebrun, the future duke of Piacenza, concluded that the budget of the école des Mines was better suited to a country like Sweden, where mining was a major source of the national income, than to an agricultural country like France. The small size of the school, moreover, did not justify the sums expended. In June of the same year, Lebrun set forth a proposal of the finance committee that the Corps des Mines and its school should be amalgamated with the Corps des Ponts et Chaussées and its famous school.33 This proposal fitted well with a plan for the reorganization of the Jardin des Plantes, which included the recommendation that the mineralogical collection of the mint should be transferred there and that its professor of chemistry should give a course in metallurgy. Neither proposal was implemented.34 Indeed, the Constituent Assembly disbanded without having legislated any reorganization of the Corps des Mines and its school.

As a teaching institution the école des Mines continued a tenuous existence; its collections, although sought by various rival bodies, remained undisturbed. A law of 1792 continued the salaries of the mine inspectors, the teachers, and the students. Sage had played a major part in defending his school, but his much-vaunted contacts with the court came more and more to endanger his position. In 1793–1794 he was arrested and imprisoned, regaining his freedom only upon payment of a substantial fine.35

In 1794 the Committee of Public Safety, now reformed but weakened in authority, created the Agence des Mines, to be composed of three members selected by the Committee.36 Of the three appointees, two had been members of the first class at the École des Mines; all three continued to dominate mining affairs until the basic reorganization in 1810.37

Sage was simply ignored during these changes. The Agence des Mines established a new school, in the Hôtel de Mouchy in the rue de l’Université, and courses began there in November 1794. The school had a library, an assaying laboratory, and its own mineralogical collection (the core of which was Guettard’s cabinet). The scientific level of the teaching staff was markedly raised. Vauquelin taught what had been Sage’s course in assaying, mineralogy and physical geography were taught by Hassenfratz, and crystallography by Haüy. Two of Sage’s original associates were retained: practical mining was again taught by Guillot-Duhamel, and the Abbé Clouet gave his course in German.38

In all this Sage played no part; but in 1797 the Directory put him once again in charge of his collections at the mint with a stipend of 6,000 francs. In 1801 he was elected a full member of the Institut de France.39 A few years later, however, he became totally blind and soon after was deprived of his pension. His last years were spent in penury, in attempts to win back public favor, and in writing pamphlets protesting his ill treatment and enumerating his real and imaginary achievements. He died in his eighty-fifth year, an unregenerate royalist, a scientific fossil, and a pathetic hangover of the ancien régime.


1. Paul Dorveaux, “Apothicaires membres de l’Académie royale des sciences, XI, Balthazar-Georges Sage,” in Revue d’histoire de la pharmacie, 23 (1935), 152–166, 216–232. For this evaluation. see p. 232.

2. Arthur Birembaut, “L’enseignement de la minéralogie et des techniques miniéres,” in René Taton, ed., Enseignement et diffusion des sciences en France au XVIIIe siécle (Paris, 1964), 387 and n. 2. édouard Grimaux describes Sage as “expérimentateur maladroit, imagination fantaisiste, qui a beaucoup publié, beaucoup écrit, entassé erreurs sur erreurs, et n’a pas laissé dans la science un seul fait bien observé.” See his Lavoisier, 2nd ed. (Paris, 1896), 122.

3. J. R. Partington, A History of Chemistry, III (1962), 97–98.

4. “Sage,” in Didot-Hoefer, Biographie générale. The biographical sketch in John Ferguson, Bibliotheca chemica, II (Glasgow, 1906), 312–313, appears to draw uncritically upon the Biographie générale.

5. A copy of this work is cited in Denis I. Duveen, Bibliotheca alchemica et chemica (London, 1949); 523.

6. Dorveaux, op. cit., 155–159.

7. The article in the Biographie générale errs in stating that in 1768, at the age of twenty-eight, Sage replaced Rouelle in the Academy of Sciences. This error reappears in Ferguson, op. cit., p. 312. A reliable source is the Index biographique des membres et correspondants de l’Académie des sciences (Paris, 1939, and later eds.).

8. An account of this episode is given by Leslie J. M. Coleby in Chemical Studies of P. J. Macquer (London, 1938), 78–79. See Oeuvres de Lavoisier, IV (1868), 159–175. For his later admission of this error, see Sage, Analyse chimique et concordance des trois règnes, I , “Preface,” v.Here, too, he admits his mistake in stating that manganese ore (pyrolusite) contains zinc: but he adds that he corrected himself by repeating the experiments of Gahn, Bergman, and Scheele, ibid., p. vi.

9. “Rapport sur une contestation entre MM. Cadet et Baumé sur le précipité per se,” in Oeuvres de Lavoisier, IV (1868), 188–190.

10. “Analyse de l’eau du lac asphaltite,” ibid., II (1862), 234–237.

11.Oeuvres de Lavoisier, V (1892), 464, 481

12.Ibid., II (1862), 445–446, 473.

13. Partington, op. cit., p. 97. This last discovery was cited with approval by Lavoisier in his important “Mémoire sur l’affinité du principe oxygine,” in Oeuvres de Lavoisier, II , 554.

14. Coleby, op. cit., pp. 114–115

15. Arthur Birembaut, “L’Académie royale des sciences en 1780 vue par l’astronome suédois Lexell (1740–1784),” in Revue d’histoire des sciences et de leurs applications, 10 (1957), 156, 163–164.

16. Charles Henry, Correspondance inédite de Condorcet et de Turgot (Paris, 1883), 123.

17.Torbern Bergman’s Foreign Correspondence, Göte Carlid and Johan Nordström, eds., I (Stockholm, 1965), 246. For similar skeptical allusions by Guyton de Morveau and by the Irish chemist Kirwan, see ibid., pp. 112, 188. During a visit to Paris in 1781–1782. Alessandro Volta followed a course in chemistry given by Sage, probably the course at the mint. See Epistolario di Alessandro Volta, II (Bologna, 1951), 79.

18. David Roger Oldroyd, “From Paracelsus to Ha“ily: The Development of Mineralogy in Its Relation to Chemistry” (Ph.D. diss., Univ. of New South Wales, 1974), I owe this reference to Professor Seymour Mauskopf of Duke University.

19. Sage, Analyse chimique, I , “Préface.” i—ii.

20.Ibid., p. 29.

21.Méthode de nomenclature chimique, proposé par MM. de Morveau, Lavoisier, Bertholet [sic], & Fourcroy (Paris, 1787), 244–249.

22.Ibid., p. 251. Sage’s open attack on the new nomenclature appeared in a series of letters published in Rozier’s Journal de physique (1788, 1789). See Dorveaux, op. cit., p. 223, n. 30.

23. Sage, Mémoires historiques et physiques, 50–51.

24. Aguillon, “L’École des mines...,” 441–443, and Rouff, Les mines de charbon, 481. On Guillot-Duhamel, see H. Guerlac, “Some French Antecedents of the Chemical Revolution,” in Chymia, 5 (1959), 93; and Alfred Lacroix, Figures des savants, I (Paris. 1932), 19–23.

25. Aguillon, op. cit., p. 446. In 1766 Bertin officially commissioned Guettard to continue, under government sponsorship, his work on a mineralogical atlas of France, a project with which Lavoisier, and later Monnet, were closely associated.

26. On Jourdan, also called Jourdan de Montplaisir, who was an inspector of mines based at Lyons, see Aguillon, op. cit., pp. 447–448. On Monnet see Rhoda Rappaport, “Guetlard, Lavoisier, and Monnet: Geologists in the Service of the French Monarchy” (Ph.D. diss., Cornell Univ., 1964), and her short article in this Dictionary with an excellent bibliography. According to Sage, Monnet was not the only influential opponent of his schemes. He charges Buffon with delaying his nomination to the chair for a year, hoping to have it awarded to his disciple Daubenton at the Jardin des Plantes. See Sage. Mémoires historiques et physiques, p. 73.

27. Aguillon, op. cit., pp. 449–451. Parington, op. cit., III , 65, describes Demeste as “a Liége surgeon who made chemistry a hobby.” Sage deserves credit for his support of Romé de l’Isle, a distinguished crystallographer whose Essai de cristallographie first appeared in 1772. In turn Romé de l’Isle, in his L’action du fen central bannie de la surface du globe (2nd ed., 1781) quotes from Sage’s experiments.

28. On Hassenfratz and Charles as teachers of physics in the early École des Mines, see Aguillon, op. cit., p. 463. The Almanach Royal for 1789 lists only Sage, “Professeur de Minéralogie Docimastique, Directeur Général des Etudes, & Commissaire du Conseil pour les Essais des Mines”; Guillot-Duhamel, “Professeur de Géométrie Souterraine, et Démonstrateur de Toutes les Machines Servant ń l’Exploitation des Mines”; and “M. de Voselles. Secrétaire Général & Garde du Cabinet du Roi.” The same names appear in the Almanach through 1792. According to the Rapport du Comité des finances—Département des Mines. Pur M. Le Brun, p. 4, the chair of foreign languages and the chair of physics were established in 1785. This and other related pamphlets can be consulted in the French Revolution collection of Cornell University.

29. In 1784 Sage published his Description méthodique du cabinet de l’École royale des mines.

30. In his Fondation de l’École royale des mines. 6 . Sage writes that the twelve éléves stipendiés were paid 500 frances as their traitements and 200 francs for their travel, presumably to visit mines.

31. Aguillon, op. cit., pp. 461–462, who adds that “en chimie et docimasie [Sage gave only] l’indication des recettes alors connues dans les laboratoires sans aucune véritable théorie scientifique pour les expliquer et les relier entre elles.”

32. Sage, Fondation de l’École royale des mines, 7.

33. Aguillon, op. cit., pp. 465–466.

34. Sage fought both proposals. In reply to Lebrun he published Remarques de M. Sage, directeur de l’École royale des mines, sur l’extrait raisonné des rapports du Comité des finances de l’Assemblée nationale (Paris, n.d. [probably 1790]). See also his Observations sur un écrit qui a pour tire, vues sur le Jardin royal des plantes et le cabinet d’histoire naturelle; á Paris, chez Baudouin, imprimeur de l’Assemblée nationale, 1789 (Paris, 1790). Both pamphlets can be consulted in the Lavoisier Collection at Cornell University. In his Mémoires historiques et physiques Sage accused Lebrun of abolishing the 2,000 francs that was his stipend as professor of minéralogie docimastique at the mint.

35. Sage rather absurdly blamed his arrest and imprisonment on Guyton de Morveau and Fourcroy, who, while members of the Committee of Public Safety, “se vengèrent du ridicule que j’avais répandu sur leur vocabulisme insignificant et sans euphonie, et de ce que j’avais prouvé que la nouvelle doctrine lavoisienne était une métachimie ... .” Mémoires historiques et physiques, 74.

36. Aguillon, op. cit., pp. 471–473.

37. The two who had studied at the École des Mines were Leliévre and Lefebvre d’Hellancourt. Both were among those commissioned (brevetés) after a single year of study.

38. Aguillon, op. cit., pp. 482–484.

39. According to the Index biographique des membres et correspondants de l’Académie des sciences. Sage had been elected associé non-résident of the section of natural history and mineralogy of the Première Classe of the Institut on 5 March 1796.


I. Original Works. The following list, with no pretense at completeness, may give some idea of the range of Sage’s interests. Examen chymique de différentes substances minérales (Paris, 1769) would seem to be his earliest publication. It was followed by Élémens de minéralogie docimastique (Paris, 1772: 2nd ed., 2 vols., 1777). Mémoires de chimie (Paris, 1773) contains, besides other papers, memoirs read to the Academy of Sciences from 1766 to 1772, many of them describing mineral analyses. These works were followed by Analyse des blés, et expériences propres á faire connaître la qualité du froment (Paris, 1776); and Observations nouvelles sur les propriétés de l’alkali fluor ammoniacal (Paris, 1778). His L’art d’essayer l’or et l’argent (Paris, 1780) contains his first description of the production of potassium ferrocyanide in solid form. This was followed by his ambitious Analyse chimique et concordance des trois régnes de la nature. 3 vols. (Paris, 1786). After the Revolution and in his later years he published various speculative works on electricity and natural philosophy, as well as his attack on Lavoisier’s chemistry and the new chemical nomenclature: Exposé des effets de la contagion nomenclative et la réfutation des paradoxes qui dénaturent la physique (Paris, 1810). Of autobiographical interest are his Mémoires historiques et physiques (Paris, 1817); Fondation de l’Ecole royale des mines á la monnaie (Paris, 1817); and Notice autobiographique (Paris, 1818). Other of Sage’s publications are cited in the notes and still others are listed in the catalog of printed books of the Bibliothéque Nationale.

II. Secondary Literature. Although a member of the Paris Academy of Sciences and (at the time of his death) of the Première Classe of the Institut de France, Sage was never accorded the customary honor of an éloge composed by the perpetual secretary. There is a passable, if not always accurate, sketch by E. M. [Ernest Mézières?] in the Didot-Hoefer Nouvelle biographie générale, based largely on Sage’s autobiographical writings and an obituary notice in the Journal de la librairie of 1824. Sage is judged by E. M. as “ayant crée la docimasie en France,” which would seem to be an exaggeration. The best modern evaluation is the two-part study by Paul Dorveaux (see Note 1); Sage’s work in chemical metallurgy is briefly mentioned by Hermann Kopp in his Geschichte der Chemie, 2 vols. in 4 pts. (Brunswick, 1843), pt. II , 87–88, but is not discussed in F. Hoefer’s Histoire de la chimie, 2 vols. (Paris, 1866). The most favorable account of Sage’s chemical work (perhaps too favorable) is by J. R. Partington in his History of Chemistry, III (1962), 97–98. On the Paris École des Mines and Sage’s role as its founder and first director, see Louis Aguillon, “L’École des mines de Paris—notice historique,” in Annales de mines, 8th ser., 15 (1889); 433–686; and Marcel Rouff, Les mines de charbon en France au XVIIIe sièele, 1744–1791 (Paris, 1922), 480–488.

Henry Guerlac