Pierre-Joseph Macquer an Eighteenth-Century Artisanal-Scientific Expert

Summary

Pierre-Joseph Macquer (1718–1784) is well known as one of the major chemists in the eighteenth century as a theoretician and a teacher. He is also known for his works on dyeing. This paper presents a new face of Macquer. He proposed a theory on mordants in dyeing as early as 1775. Besides his activity at the Académie des sciences, he played an important role in Government as the commissioner of dyeing from 1766 where he established close links with artisan inventors. Académicien chimiste at the royal Manufactory of Sèvres from 1757, he was also the inventor of French porcelain. His notebooks show his organization, method, courage, passion and obstinacy in the search for the paste for hard porcelain. He also proposed an interpretation of its formation. Macquer was both a theoretician and a practical expert in dyeing as well as in porcelain making. He managed to bridge the gap between science and art.

Acknowledgements

I would particularly like to thank Ursula Klein who gave me the opportunity to develop this research through her invitation to the workshop ‘Artisanal-Scientific Experts in Eighteenth-Century France and Germany’. I also thank her for editing this article and for her valuable comments and suggestions, which resulted in important improvements and clarifications. I would also like to thank the anonymous referee for his constructive criticism, and finally John Perkins for reviewing the English of the final version.

Notes

¹Pierre-Joseph Macquer and Antoine Baumé, Plan d'un cours de chymie expérimentale et raisonnée avec un discours historique sur la chymie (Paris, 1757).

²Pierre-Joseph Macquer, Elémens de chymie théorique (Paris, 1749), 256–73; Macquer, ‘Affinités’, Dictionnaire de chymie (Paris, 1766), 47–55.

³This mission is précised in a letter sent to Claude-Louis Berthollet when he succeeded Macquer: letter dated 24 February 1784, Archives nationales, F¹² 1329. On Macquer's death, in 1784, his post as the Commissaire Général of the Bureau du Commerce for dyeing was very sought after. Five candidates applied for it: Antoine François de Fourcroy, Jean-François Pilâtre de Rozier, Auguste-Denis Fougeroux de Bondaroy, Antoine Baumé and Claude-Louis Berthollet. On Berthollet's appointment to this post, Calonne the Contrôleur général des finances justified the relatively modest annual salary of 2000 Livres by ‘the inconsiderable work that it required’, same letter, Archives nationales, F¹² 1329. This did not in any way reflect the amount of time and energy that Macquer had devoted to this post.

⁴Draft of the first memoir on Prussian blue, library of the Muséum d'histoire naturelle Paris, Ms 283, I, p. 1. More generally see L.J.M. Coleby, The Chemical Studies of P. J. Macquer (London, 1938), 52–9, 85–96; John J. Beer, ‘Eighteenth Theory on Dyeing’, Isis, 51 (1960) 21–30; More recently, Sarah Loewengard, The Creation of Colors in Eighteenth-Century Europe (New York, 2007), http://www.gutenberg-e.org/lowengard/. Also see Christine Lehman, ‘L'art de la teinture à l'Académie royale des sciences au XVIII^e siècle’, Methodos, [on line], 12/2012, http://methodos.revues.org/2874.

⁵L.J.M. Coleby, ‘A History of Prussian Blue’, Annals of Science, 4 (1939) 206–11; Alexander Kraft, ‘On the Discovery and History of Prussian Blue’, Bulletin for the History of Chemistry, 33 (2008) 61–7. Stahl evoked the preparation of Prussian blue in his Experimenta, Observationes, Animadversiones CCC numero etc … (Berolini, 1731), 281.

⁶John Woodward, ‘Præparatio Cærulei Prussiaci ex Germaniâ missa ad Johannem Woodward’, Philosophical Transactions, 33 (1724) 15–7.

⁷Calcinated ox blood was a substance regarded to be rich in phlogiston with which alkali salt (niter fixed by tartar) formed a kind of soap, which Geoffroy compared with Starkey's soap. Macquer called it alkaline liquor, sulphurous or soapy liquor; alum was a combination of vitriolic acid and of a white, fine and absorbent earth; martial vitriol was a solution of vitriolic acid and iron.

⁸John Brown, ‘Observations and Experiments upon the foregoing Preparation’, Philosophical Transactions, 33 (1724), 17–24 (24).

⁹Loewengard (note 4); Etienne-François Geoffroy, ‘Observations sur la préparation du Bleu de Prusse ou de Berlin’, Mémoires de l'Académie royale des sciences (1725 [1727]), 153–72 and 220–37; Histoire de l'Académie royale des sciences (1725), 33–8; Claude-Joseph Geoffroy, ‘Differens moyens de rendre le Bleu de Prusse plus solide à l'air & plus facile à préparer’, Mémoires de l'Académie royale des sciences (1743), 33–50; M. l'Abbé Ménon, ‘Mémoire sur le bleu de Prusse’, Mémoires présentés à l'Académie royale des sciences par les sçavans étrangers (1750), I, first memoir 563–72 and second memoir 573–92. Perpetual secretary of the Academy of Angers, the Abbé Menon was the demonstrator of Réaumur's collection.

¹⁰Pierre-Joseph Macquer, ‘Sur une nouvelle espèce de Teinture bleue dans laquelle il n'entre ni Pastel, ni Indigo’, Mémoires de l'Académie royale des sciences (1749 [1753]), 255–65; Histoire de l'Académie royale des sciences (1749), 111–5. The memoir was read on April 16 and 26, 1749 (PV 1749 folios 204–08 and 249). A part of the draft of this memoir is kept in the library of the Muséum d'histoire naturelle Paris, Ms 283, I.

¹¹Letter from Macquer to Monseigneur de Machault, Contrôleur Général des finances, AN F¹² 2259. The letter is undated but Hellot's report to the Bureau du Commerce was dated October 1748.

¹²Macquer (note 10), 257–62. For a detailed discussion of the various operations, see Coleby (note 4), 85–7.

¹³Agustí Nieto-Galan, ‘Between Craft Routines and Academic Rules: Natural Dyestuffs and the Art of Dyeing in the Eighteenth-Century’, in Materials and Expertise in Early Modern Europe, edited by Ursula Klein and E. C. Spary (Chicago, 2010), 330–3. The dyed cloth had to be submitted to a series of reference tests called ‘débouillis’. If the piece of cloth could withstand being immersed for the specified time in boiling baths of soap, alum and tartar, it was then qualified as grand teint (fast dye, i.e. high quality and price); otherwise it was only petit teint (fugitive dye).

¹⁴M. l'abbé Ménon (note 9), I, second memoir, 589.

¹⁵ Académie des sciences, sealed note No. 23, Pochette de séance of 23 April 1749. The Abbé Menon's death in September 1749 stopped the dispute and extinguished the polemics, and Macquer remained alone in his interest in this dye. This explains the very late opening of this sealed note: 27 October 1954. A sealed note was deposited by an academician to mark the priority of an invention. It was opened at the author's request or by the Académie after the author's death.

¹⁶Pierre-Joseph Macquer, ‘Examen chymique du bleu de Prusse’, Mémoires de l'Académie royale des sciences (1752 [1756]), 60–77.

¹⁷Coleby (note 4), 54–9.

¹⁸Macquer (note 16), 70. This interpretation was later adopted by Baumé in his commentary on Prussian blue: ‘In this operation one can see two decompositions & two new compositions, it is an example of double affinity that we said to be composed of four bodies’. Antoine Baumé, Manuel de Chymie ou exposé des opérations de la Chymie et de leurs produits, 2^nd ed. (Paris, 1766), 209.

¹⁹ Académie des sciences, biographical file Macquer. Prussian blue is Macquer's fifth academic memoir.

²⁰ Histoire de l'Académie royale des sciences (1756 [1762]), 53–9. Hellot disclosed to the Académie the recipes of a private individual famous for preparing ‘the most beautiful Prussian blue that can be used’.

²¹Antoine Baumé (note 18), 205–13; Peter Shaw, Leçons de Chymie propres à perfectionner la Physique, le Commerce et les Arts (Paris, 1759), 306–8. This book was translated by Madame Thiroux d'Arconville, a friend of Macquer; Guyton de Morveau, Digressions académiques ou essais sur quelques sujets de Physique, de Chymie & d'Histoire naturelle (Dijon and Paris, 1762), 244–50. Guyton based himself on Macquer's conclusion that Prussian blue was formed from iron with the flammable matter of the sulfurous lye. He established that phlogiston, or flammable matter, was not the only substance united to metal earth in Prussian blue. He presented the hypothesis that phlogiston retained a solvent of iron or an animal acid in this combination.

²²Library of the Muséum d'histoire naturelle Paris, Ms 283, V and VI.

²³In 1765, Hellot was charged by the Académie des sciences with settling a dispute between a manufacturer of Prussian blue and the master painters who had confiscated his equipment. Hellot's verdict was clear: ‘because the preparation of this colour is within the scope of chemistry, I believe that any private individual can practice it without infringing any regulations of any community’. Proceedings of the Académie royale des sciences, 1765, folios 100 recto–101 recto.

²⁴This was the way used by Cabanis to show the presence of iron in the coloured part of blood. Pierre-Jean Georges Cabanis, Cours de chimie, undated manuscript but later than 1776, Library of the Muséum d'histoire naturelle Paris, Ms 2039, folio 40 recto.

²⁵De la Folie, Avis utile pour le commerce, Archives nationales F¹² 2259. Examination in 1778 by Mignot de Montigny dated January 10, F¹² 1329 and report dated 11 January 1778, F¹² 2259.

²⁶Macquer (note 10), 265.

²⁷Macquer, L'art de la teinture en soie (Académie des sciences, description des Arts et Métiers, 1763).

²⁸In the Avant-propos of l'Art de la teinture en soie, Macquer stated: ‘I followed exactly all the details of the operations and I wrote them down’. As early as 1753 his experimental notes mention the difficulties of colouring raw silk and the various ingredients in which raw silk can be boiled. Library of the Muséum d'histoire naturelle Paris, Ms 283, I.

²⁹According to the statement of Antoine Francois Brisson, inspector of Lyons Manufactures, Museum Ms 283 VI (9). Pierre-Joseph Macquer, ‘Sur un moyen de teindre la soie en un rouge vif de Cochenille & de lui faire prendre plusieurs autres couleurs plus belles & plus solides que celles qu'on a faites jusqu’à présent’, Mémoires de l'Académie royale des sciences (1768), 82–90; Histoire de l'Académie royale des sciences (1768), 54–7; Méthode pour teindre la soie en plusieurs couleurs de rouge vif de cochenille, & autres couleurs, (Paris, 1769).

³⁰On Andrinopolis red see Angélique Kinini, ‘The fabrication of Turkish red in Thessaly at the end of the eighteenth century: manufactures of Ampékalia city’, in Natural Dyestuffs and Industrial Culture in Europe (1750–1880), edited by Robert Fox and Agustí Nieto-Galan (Sagamore Beach, 1999), 71–100.

³¹ Mémoire concernant le procédé de la teinture du coton rouge-incarnat d'Andrinople sur le coton filé (Paris, 1765).

³²Pierre-Joseph Macquer, ‘Recherches sur la théorie de la teinture du coton en rouge de Garence, connue sous le nom de Rouge d'Andrinople avec un nouveau procedé beaucoup plus simple et beaucoup plus court pour faire ce rouge aussi solide et encore plus beau’, Bibliothèque Nationale de France (BNF), Ms NAF 2761 folios 147 recto–148 verso.

³³Pierre-Joseph Macquer, ‘Recherche sur les procédés par lesquels on teint en rouge solide de garence les fils de coton, de chanvre et de lin avec des considerations générales sur les mordants en teinture’, The reading was started on May 31 and ended on June 1775. Archives nationales, F¹² 2259. It seems that this memoir was never published.

³⁴Macquer (note 33), folio 14.

³⁵Berthollet, Éléments de l'art de la teinture [Paris, an XIII (1804)], I, 60.

³⁶Berthollet (note 35), 63. This was the Indigo Prize competition in which Bergman was awarded an accessit for his analysis. His memoir appeared in the Mémoires des Sçavans étrangers : Torbern Bergman, ‘Analyse et examen chimique de l'Indigo, tel qu'il est dans le commerce pour l'usage de la Teinture. Pièce qui a concouru pour le Prix sur la nature & l'usage de l'Indigo’, Mémoires de mathématique et de physique, présentés à l'Académie royale des Sciences, par divers sçavans, & lûs dans ses assemblées, IX, (1780), 123–64.

³⁷Berthollet (note 35), 64.

⁴⁰Pierre-Joseph Macquer, Dictionnaire de Chymie (Paris, 1778), IV, 26.

³⁸Mi Gyung Kim, Affinity, that Elusive Dream: A Genealogy of Chemical Revolution, (Cambridge, MA, 2003), 203.

³⁹Bernadette Bensaude-Vincent and Agustí Nieto-Galan, ‘Theories of Dyeing: A View on a Long-standing Controversy through the works of Jean-François Persoz’, in Fox and Nieto-Galan (note 30), 3–24 (6); Nieto-Galan (note 13), 333.

⁴¹From 1700 to 1722 it was known as the Conseil de Commerce, and from 1722 to 1791 as the Bureau du Commerce. Its responsibilities were regulated by an ordinance of the Conseil d’état of 29 June 1700.

⁴²Pierre Bonnassieux, Conseil de commerce et bureau du commerce 1700–1791. Inventaire analytique des procès verbaux (Paris, 1900), introduction by Eugène Lelong, xxvii-xxxi. Harold T. Parker, An Administrative Bureau during the Old Regime: The Bureau of Commerce and its Relations to French Industry from May 1781 to November 1783 (London and Toronto, 1993).

⁴³Archives nationales, F¹²2259.

⁴⁴See note 43.

⁴⁵It was the key criterion for high quality dyeing or grand teint (fast dye).

⁴⁶Archives nationales F¹²2259, copy of a letter from Macquer to Denis, 16 February 1771, my emphasis.

⁴⁷Library of the Muséum d'histoire naturelle Paris, Ms 283, VI and VII.

⁴⁸For this work, he was granted an exceptional remuneration of 4000 Livres per year, in addition to his salary as a commissioner. A further 600 Livres were added in order to pay a man ‘in charge of heavy works caused by the series of experiments’. This amount of 4600 Livres was to be paid throughout the duration of the work. Archives Nationales F¹² 1330.

⁴⁹A report of the public session held on 14 November 1781 was published in the Mercure de France dated 5 December 1781, 196. Pierre-Joseph Macquer, Prospectus et plan d'une description générale de l'Art de la teinture (Paris, 1782).

⁵⁰Nieto-Galan (note 13), 337–8.

⁵¹The manufacture founded in 1740 was located at Vincennes; it was transferred to Sèvres in 1756. On the history of hard-paste porcelain at Sèvres, see Antoine d'Albis, Sèvres (1756–1783). La conquête de la porcelaine dure, histoire inédite de la manufacture au XVIII ^e siècle, Dossier de l'Art (Dijon, 1999). On Macquer's researches on porcelain, see Willem Constantin Alhers, Un chimiste du XVIII ^e siècle, Pierre-Joseph Macquer (1718–1784). Aspects de sa vie et de son œuvre, Thèse de 3 ^ème cycle (1969), 105–30 and annexes 201–9 and 227–234; Coleby (note 4), 96–110.

⁵²From 1753, Hellot received a gratification of 1200 livres per year ‘as recognition of the care he devotes to the compositions used in making the paints and gilding of porcelain, the secret of which his Majesty has reserved to himself’. Service des collections documentaires de Sèvres – Cité de la céramique, F2. Macquer carefully copied in a 280-page notebook this collection of all the processes of the manufacture of Vincennes ‘Recueil de tous les procédés de la manufacture de Vincennes décrits pour le Roy, Sa Majesté s'en etant reservé le secret par Arret du 19 août 1753 par M ^r Hellot de l‘Acad ^e Rle des Sciences’, Collections documentaires Sèvres Y52.

⁵³He received the same salary as Hellot. From 1760 on, he was the only one in charge of this work; Collections documentaires Sèvres, D1.

⁵⁴Nicholas Zumbulyadis, ‘Bötger's Eureka!: New Insights into the European Reinvention of Porcelain’, Bulletin for the History of Chemistry, 35 (2010), 24–32.

⁵⁵Collections documentaires Sèvres, Y 52, 4.

⁵⁶Didier-François d'Arclais de Montamy, ‘Porcelaine de la Chine (Art de la poterie)’, Encyclopédie ou Dictionnaire raisonné des Sciences, des Arts et des Métiers, par une Société de gens de Lettres. Diderot et D'Alembert (Paris, 1765). XIII, 106–22; Nicolas-Christian de Thy, Comte de Milly, L'art de la porcelaine (Paris, 1771).

⁵⁷i.e. infusible at high temperature.

⁵⁸René-Antoine Ferchault de Réaumur, ‘Idée générale des différentes manières dont on peut faire la porcelaine et quelles sont les différentes matières de celle de la Chine’, Histoire et mémoires de l'Académie royale des sciences (1727 [1729]), 185–203; Jean Torlais, Un esprit encyclopédique en dehors de l'Encyclopédie, Réaumur d'après des documents inédits (Paris, 1961), 93–105.

⁵⁹The date is certified by his fees (F4) and his personal expense book (Y59).

⁶⁰Macquer's letter to Boileau, director of the manufacture, 11 December 1760, BNF, Ms Fr 9135, folios 10 recto–11 verso. Antoine Baumé, ‘Porcelaine (Art de fabriquer la)’, Dictionnaire portatif des arts et métiers (Paris, 1766), II, 420–35. The qualities of beautiful porcelain described on pages 421–3 were reproduced in full by the Comte de Milly in the avant-propos of his Art de la porcelaine (note 56), xij–xxiij.

⁶¹‘Déposé cacheté au secrétariat le 27 janvier 1751, ouvert à l'Académie le 29 janvier 1766 à la demande de l'auteur’, Archives of the Académie des sciences, pochette de séance of 27 January 1751 and Procès verbal of the same day, folio 10 recto.

⁶²Étienne Guettard, ‘Mémoire sur les granits de France comparée à ceux d’Égypte’, Histoire et mémoires de l'Académie royale des sciences (Paris, 1751), footnote p. 210.

⁶³Pierre-Joseph Macquer, Recueil des experiences chimiques faites pour la perfection de la porcelaine de la Manufacture royale etablie à Seves par M. Macquer de l'academie Royale des sciences. The first notebook reports the 666 experiments, carefully numbered, performed between 1757 and 1760; it is complemented by a second notebook with experiments numbered from 687 to 1101, performed between 1760 and 1761. Isolated experiments for studying earths only are referenced by means of a specific numbering, Collections documentaires Sèvres Y57 and Y58.

⁶⁴For Macquer, only clayey stones mixed with limestone, gypsum and pebbles or the mixture of gypsum and pebbles were fusible.

⁶⁵Test No. 36: ‘On the other hand, it is constant in all chemical experiments that gypsum and all gypsum stones are composed of vitriolic acid united with a calcareous stone of a particular nature’, Y57.

⁶⁶In the expense book the interruption due to the chemistry course is recorded from September 30 to June 1758. The expenses related to the test furnace appear on 15 January 1759. Collections documentaires Sèvres Y59.

⁶⁷One gros of earth from Amilli, 2 gros of stones and 18 grains of sand of earth of Lyons.

⁶⁸Letter from Macquer to Boileau, 11 December 1760, BNF, Ms Fr 9135. Millot, the furnace chief, witnessed more than 1500 to 1800 tests in Macquer's laboratory and affirmed that he himself had carried out more than 1200 others. Collections documentaires Sèvres Y59bis.

⁶⁹Pierre-Joseph Macquer, ‘Mémoire sur les argilles, et sur la fusibilité de cette espèce de terres, avec les terres calcaires’, Mémoires de l'Académie royale des sciences (1758), 155–76 (159).

⁷⁰‘Contract between Macquer and Baumé for the chemistry course’, BNF manuscript, Ms Fr 9134 folios 82–4. This contract dated June 16 1757 was transcribed by J.P Contant, L'enseignement de la chimie au jardin royal des plantes de Paris (Cahors, 1952), 65–9.

⁷¹‘Mr. Baumé consented to help me and to share with me the considerable work that had to be done on these objects’, Macquer (note 69), 160.

⁷²This project, written on the last page of the first experiment notebook, Y57, was alluded to in a letter from La Bourdonnais de Bois Hullin to Macquer on 25 September 1761: ‘Should you by chance be tempted to create a plant in Brittany, we could tell you places where wood is cheaper and where facilities are available’, BNF, Ms Fr 9135. Philippe Macquer, a lawyer at the Parlement, was very close to his brother Pierre-Joseph; he seems to have been his prête-nom for publishing the Dictionnaire des Arts et Métiers in 1766, the same year as the Dictionnaire de Chymie.

⁷³BNF, Ms Fr 9135, folio 14 recto-verso.

⁷⁵Pierre-Joseph Macquer, ‘Sur la cause de la fusion des terres et des pierres les unes dans les autres’, pochette de séance of the Académie des sciences of 16 December 1758.

⁷⁴Johann Heinrich Pott, Lithogéognosie ou Examen chymique des pierres et des terres en général, et du talc, de la topaze, & de la stéatite en particulier, avec une dissertation sur le feu & sur la lumière (Paris, 1753).

⁷⁶ Histoire de l'Académie royale des sciences (1758), 57–62; Macquer (note 69), 155–76. The reading started on 26 May, continued on 9 June and ended on 12 June 1762.

⁷⁷Macquer (note 69), 176.

⁷⁸Jean D'Arcet, ‘Mémoire sur l'action d'un feu égal et violent continué pendant plusieurs jours sur un grand nombre de pierres & de chaux métalliques, essayées pour la plupart telles quelles sortent du sein de la terre’, Histoire de l'Académie royale des sciences (1766 [1769]), 75–9. The report of the commissioners, Macquer, de Montigny and Jussieu was printed with the text of the memoir (Paris: Cavelier 1766), 108–22.

⁷⁹Pierre-Joseph Macquer, ‘Mémoire sur l'action d'un feu violent de charbon appliqué à plusieurs terres, pierres et chaux métalliques’, Mémoires de l'Académie royale des sciences (1767 [1770]), 298–313 and Histoire de l'Académie royale des sciences, 57–62.

⁸⁰Collections documentaires Sèvres B2 and B3.

⁸¹Report of 31 August 1764, Collections documentaires Sèvres B3.

⁸²Étienne Guettard, ‘Histoire de la découverte faite en France de matières semblables à celles dont la porcelaine de Chine est composée, lûe à l'Assemblée publique de l'Académie Royale des sciences le mercredi 13 novembre 1765 par M. Guettard de la même Académie’, (Paris, 1765). The reading was repeated at the ordinary meetings of 16 and 23 November 1765 (PV folios 385 and 386 versos); the printed text was distributed on 8 January 1766.

⁸³Guettard's manuscripts kept at the library of the Muséum d'histoire naturelle prove that he really had succeeded in making porcelain, Ms 175, technology file. The ‘cahier de laboratoire 1748–1750 des expériences réalisées avec Monseigneur’, the tests of couverte, ‘les expériences sur la porcelaine’ are all proofs of his success. Moreover, Guettard's experiments were also evoked by Madame Thiroux d'Arconville in the preliminary dissertation to her translation of the Leçons de Chymie by Peter Shaw (Paris, 1759), lxj.

⁸⁴Lauraguais’ first reply was on 22 January 1766. On 29 January the opening of Guettard's sealed note instigated the reading of one by Lauraguais deposited in the registers because it was based on Le Guay's testimony. The dispute between Guettard and Lauraguais continued until the distribution on 19 March of a printed text of Lauraguais’ observations, for which the Académie appointed Nollet, de Montigny and Leroy as commissioners.

⁸⁵Pierre-Joseph Macquer, Recette d'une porcelaine nouvelle de ma composition dont j'ai déposé à l'academie des essais consistans en deux souscoupes et trois petites tasses en couverte, aujourdhui samedi 12 juillet 1766. This sealed note, No. 119, is kept in the Macquer's biographical file at the l'Académie des sciences. It was opened on 13 March 1967 at the request of Mr. Alhers. The five porcelain pieces ‘sealed with two black wax stamps’ are recorded in the inventory of the Cabinets de l'académie royale des sciences 1765, library of the Institut de France, Ms 1387, folio 287.

⁸⁶In his observations Macquer proposed alternative solutions: any really pure white clay could be used instead of Lyons earth, the sand of the latter could be substituted for spath of Alençon or Hertré, and fine sands or any sandstone could replace Aumont sand.

⁸⁷Alum was composed of a white clayey earth (pure clay) and vitriolic acid. By neutralizing the acid Macquer isolated white clay, the basis of porcelain.

⁸⁸Montamy (note 56), 106–22; Baumé (note 60); Macquer, ‘Porcelaine’, Dictionnaire de chymie (Paris, 1766), II, 271–91.

⁸⁹D'Albis (note 51), 12–33.

⁹⁰Pierre-Antoine Hannong, whose father owned a porcelain manufactory at Frankenthal in Germany, had sold the secret of hard porcelain paste to the manufactory of Sèvres. He brought workmen, equipment, and earths from Germany and had furnaces built. He succeeded in his first attempts at hard porcelain as it was fabricated in Saxony, and revealed its secret on 1 September 1763. Hannong, ‘Secrets de la porcelaine de Franckenthal’; Pierre-Joseph Macquer, ‘Exposition et description des matériaux et des manipulations qu'on employe pour la composition de la porcelaine que le S ^r Pierre Antoine Hannong a présentée et dont il a vendu les secrets à la manufacture du Roy par acte’, Collections documentaires Sèvres C2. In a report dated 7 August 1764, Macquer noted that he had personally verified the experiments, BNF, Ms Fr 9135, folios 19 recto–20 recto. See d'Albis (note 51), 12–9.

⁹¹Pierre-Joseph Macquer, ‘Rapport de M. Macquer à M. de Courteille relatif à ses expériences pour la fabrication de la porcelaine dure’, 28 avril 1763, Collections documentaires Sèvres C2.

⁹²The journey to Bordeaux and its vicissitudes deserves a separate discussion which exceeds the scope of this paper.

⁹³More than 200 tests were reported by Dufour, assistant to the furnace chief Millot; Collections documentaires Sèvres C2.

⁹⁴ Mercure de France, July 1769, 190–202; Journal des sçavans (1769), 558–565. The new porcelain had all the requisite qualities, in particular withstanding boiling water and resisting sudden temperature variations.

⁹⁶Macquer (note 69), footnote p. 160.

⁹⁵Hellot's poor health compelled Macquer to carry out the work alone from 1760.

⁹⁷On his trips to Paris, the archbishop of Bordeaux handed over to Macquer samples of kaolin discovered in his diocese by a surgeon's wife who was searching for a white earth for her washing. D'Albis (note 51), 26–32.

⁹⁸BNF, Ms Fr 9135, 12305 and 12306; Archives nationales, fonds privé Malesherbes 399/AP/133: letter dated 9 June 1764 addressed to Macquer; Macquer answered on 17 June 1764.

⁹⁹‘He handed over to Mrs. Bertin and de Courteille some pieces from these first tests, and even the King saw some of them with which he appeared satisfied’, BNF, Ms Fr 9135, folio 44 verso.

¹⁰⁰‘The new china all in white and gold was on a special table. There were about sixty pieces all very beautiful’. The copy of Macquer's letter to his brother is kept at the BNF, Ms Fr 9135, folios 182 verso–187 verso. This account was printed in the Moniteur des arts dated February 1864 and transcribed in full by Alhers (note 51), 227–34.

¹⁰¹In 1761, Louis Claude Cadet de Gassicourt (1731–1789) proposed to the manufacture a process for removing the stains that persisted on china and requested the reversion of Hellot's post, Collections documentaires Sèvres D1 ; Macquer's letter to Boileau dated 11 December 1760, BNF Ms Fr 9135. See also ‘Essais des procédés non acceptés à la manufacture’, Collections documentaires Sèvres C3.

¹⁰²Macquer's letter to the Marquis de Birague dated 21 February 1767, BNF Ms Fr 9135, folio 23 recto–24 verso.

¹⁰³i.e. let the silk slowly cool down in the colouring bath.

¹⁰⁴Macquer's death before completing his Description générale de l'Art de la teinture unfortunately makes it impossible to assess the influence on this fundamental work of the experience acquired during his evaluations at the Bureau du Commerce.

¹⁰⁵The concept of hybrid artisanal-scientific expert has been introduced by Ursula Klein. See Ursula Klein,‘Technoscience avant la lettre’, Perspectives on Science, 13 (2005), 226–66.