¹ ‘Extrait de deux mémoires sur le gypse’, in Oeuvres de Lavoisier (6 vols., Paris, 1862–1893), iii. 109.Google Scholar The italics are mine. The second of the two memoirs on gypsum was read to the Académic des Sciences on 19 March 1766, and this abstract was probably written after that date but before October 1766, when Lavoisier modified his views on ‘les anciennes limites de la mer’.

² Opuscules physiques et chimiques (Paris, 1774)Google Scholar, in Oeuvres de Lavoisier, i. 441.Google Scholar I am indebted to Henry Guerlac for drawing my attention to this passage. See also Rappaport, R., ‘Lavoisier's geologic activities, 1763–1792’, Isis, lviii (1967), 383, and note 33.Google Scholar

³ Oeuvres de Lavoisier, v. 226.Google Scholar Cf. Guerlac, H., ‘A note on Lavoisier's scientific education’, Isis, xlvii (1956), 211–16.CrossRefGoogle Scholar

⁴ Details of his activities during this period are in Rappaport, op. cit. (2).

⁵ Buffon, , ‘Théorie de la terre’, in Oeuvres complètes de Buffon, ed. de Lanessan, J.-L. (14 vols., Paris, 1884–1885), i. 34–66Google Scholar, and ‘Cours de chymie de M. Rouelle, rédigé par M. Diderot et éclairci par plusieurs notes’, Bibliothèque Municipale de Bordeaux, MSS. 564–5, pp. 567–82. Guettard never emphasized a general theory of the earth but at least once he expressed views close to those of Buffon and Rouelle and claimed to have held them for some years (Muséum d'Histoire Naturelle, Paris, MS. 2193, ff. 18–20).

⁶ The term ‘pelagic’ had a broader meaning in the eighteenth century than at present, signifying anything to do with the open seas, at any depth; and it will be used in that sense throughout this study. See also note 34.

⁷ Buffon, , op. cit. (5), i. 56.Google Scholar

⁸ Ibid., i. 34–66, 104 ff. Cf. Guettard, , ‘Mémoire sur les poudingues. Seconde partie, Mémoires de l'Académie Royale des Sciences, 1753 (1757), pp. 181–2.Google Scholar Cf. de Maillet, Benoît, Telliamed, trans, and ed. Carozzi, Albert V. (Urbana, Illinois, 1968), especially pp. 65–72Google Scholar, and Carozzi's comments on Buffon on p. 4.

⁹ Rouelle cited by Lavoisier, ; see below, p. 252.Google Scholar

¹⁰ Guettard, , ‘Mémoire et carte minéralogique sur la nature & la situation des terreins qui traversent la France & l'Angleterre’, Mém. Acad. R. Sci. 1746 (1751), pp. 363–92.Google Scholar See also Rappaport, R., ‘The Geological Atlas of Guettard, Lavoisier, and Monnet: conflicting views of the nature of geology’, in Schneer, C. J. (ed.). Toward a history of geology (Cambridge, Mass., 1969), pp. 272–87.Google Scholar

¹¹ Rouelle, , op. cit. (5), p. 574.Google Scholar On occasion Rouelle also used tractus lithologically, for example in tractus calcaire (ibid., p. 572).

¹² Oeuvres de Lavoisier, iii. 126.Google Scholar

¹³ Ibid., iii. 135.

¹⁴ Ibid., iii. 137

¹⁵ Ibid., v. 12–13.

¹⁶ Lavoisier Papers, Académie des Sciences, dossier 420 (notes dated 1765, on the route from Paris to Senlis).

¹⁷ Lavoisier Papers (16), dossier 423 (25 March 1764). To judge from other notes in this dossier, the date should actually read 1765. It is possible, too, that Lavoisier had read the work of one of Buffon's severest critics: Raspe, R. E., Specimen historiae naturalis globi terraquei (Amsterdam, 1763)Google Scholar. This volume was in Lavoisier's library. Of the several catalogues of the library, I have consulted the ‘Catalogue des livres de la bibliothèque de Madame la Comtesse de Rumford’ (2 vols.), in the Lavoisier papers, Cornell University Library; see especially i. 62–80.

¹⁸ Lavoisier Papers (16), dossier 420 (3 June 1765). This kind of explanation was (and is) not unusual; cf. Guettard (op. cit. [10]), who admits the existence of local exceptions to his system of bandes, but says they do not invalidate the scheme he is proposing.

¹⁹ Rappaport, , op. cit. (2), 378–9Google Scholar, and op. cit. (10), 281. Buffon noted briefly that the barometer can be used to measure accurately the height of mountains; see Oeuvres complètes de Buffon, i. 136.Google Scholar

²⁰ Oeuvres de Lavoisier, v. 75.Google Scholar See also Lavoisier Papers (16), dossiers 415, 419, and Rappaport, , op. cit. (10), 282.Google Scholar

²¹ See Oeuvres complétes de Buffon, i. especially 229–30Google Scholar, and Guettard, , ‘Description minéra-logique des environs de Paris’, Mém. Acad. R. Sci. 1756 (1762), pp. 225–7.Google Scholar Disagreement between Guettard and Lavoisier on the subject of map-making is discussed in Rappaport, , op. cit. (10), especially 278–9.Google Scholar

²² Lavoisier Papers (16), dossier 421: ‘Observations mineralogiques faittes en 8^bre 1766 dans [une] partie du vallois du Soissonnois de la champagne et de la Brie’, ff. 1v–2r.

²³ Ibid., ff. 2r, 2v, 3r.

²⁴ This is evident from an examination of the maps based on this voyage; the relevant map numbers and titles are given in Duveen, D. I., Supplement to a bibliography of the works of Antoine Laurent Lavoisier 1743–1794 (London, 1965), pp. 131–2.Google Scholar

²⁵ The journals are at the Académie des Sciences and at Cornell University Library. For a discussion of the period after 1770 see Rappaport, , op. cit. (2), 380–4.Google Scholar

²⁶ Oeuvres de Lavoisier, v. 187, 203.Google Scholar Cf. a minute of a letter from Lavoisier to the Académie (undated but written after Guettard's death on 6 January 1786), Lavoisier Papers, Cornell University Library, MS. 29. In this letter Lavoisier emphasizes that specimens he wants to analyse must be clearly identified as to place of origin.

²⁷ Oeuvres de Lavoisier, v. 198Google Scholar and Plates. He also noted that the superior beds can be destroyed by a subsiding ocean and that the number of beds therefore may be fewer than the number of ‘excursions’ of the sea.

²⁸ Ibid., v. 48–52, 72–83. The corresponding maps are dated 1766 and numbered 26 and 40^bis, the former in the Atlas et description minéralogiques de la France (Paris, 1780)Google Scholar, the latter in the rare second edition of the Atlas and reproduced in Rappaport, , op. cit. (10), 280.Google Scholar

²⁹ Muséum d'Histoire Naturelle, Paris, MS. 237, folder 6. An early date is suggested by the fact that the sketches are accompanied by a separate note dated 1770 and are in a folder labelled by Lavoisier: ‘Histoire naturelle memoire/generale/Tractus Calcaire. (Coupes géologiques.)’. The term tractus is characteristic of his youthful notes. Evidence for a later date includes the use of the word ‘géologie’, which was not widespread in France before about 1780.

³⁰ Lavoisier Papers (16), dossier 335B, f. 2v.

³¹ Oeuvres de Lavoisier, v. 201–4.Google Scholar

³² See Needham, J. T., Recherches physiques & métaphysiques sur la nature & la religion, & une nouvelle théorie de la terre, in Spallanzani, Lazzaro, Nouvelles recherches sur les découvertes microscopiques, et la génération des corps organisés (2 vols, in 1, London and Paris, 1769), ii. especially 82, 102–3Google Scholar, where Needham uses sedimentation rates as evidence for an extended time scale. Lavoisier's copy of this work is at Cornell University and, although used in appearance, contains no marginalia.

³³ The latter point, often emphasized by historians of geology, has here been subordinated to those ideas which Lavoisier himself considered most important and treated at length. Lavoisier emphatically attributed to the mathematician Gaspard Monge his ideas on the development of life on earth; see Oeuvres de Lavoisier, v. 202.Google Scholar Monge is not known to have had any competence in geology, but some evidence for his interest in natural history and his participation in conversations in Lavoisier's laboratory can be found in Aubry, Paul V., Monge: le savant ami de Mapoléan Bonaparte, 1746–1818 (Paris, 1954), pp. 30, 39Google Scholar, and Taton, René, L'oeuvre scientifique de Monge (Paris, 1951), p. 324.Google Scholar

³⁴ Lavoisier Papers (16), dossier 335C, f. 4v, and Oeuvres de Lavoisier, v. 189.Google Scholar These terms occur here for the first time in Lavoisier's writings. In the published memoir he claimed to be following Rouelle's usage, but this is not borne out by the Rouelle manuscripts. Buffon is the only one of Lavoisier's teachers known to have used these terms and then in only one passage: Oeuvres complètes de Buffon, i. 128.Google Scholar But the terms are Latinisms that Lavoisier could have found in other works, such as Raspe, R. E., An account of some German volcanes, and their productions (London, 1776), pp. 15, 17.Google Scholar Raspe's book was in Lavoisier's library.

³⁵ Oeuvres de Lavoisier, v. 206, 213.Google Scholar