1. See S. H. Mauskopf, "The Atomic Structural Theories of Ampère and Gaudin: Molecular Speculation and Avogadro's Hypothesis," Isis , 60 (1969), 61-74. [BACK]

2. Dumas explained his concept of mechanical types in "Mémoire sur la loi des substitutions et la théorie des types," C.r. , 10 (1840), 149-178 (on pp. 163-164). He depicted the molecule as a "building" in which the "framework"could be altered but not removed without dissolution of the compound (pp. 174-175). [BACK]

4. P. Thenard, "Suite des recherches sur le phosphore," C.r. , 25 (1847),892-894. [BACK]

5. J. Harris and W. H. Brock, "From Giessen to Gower Street: Towards aBiography of Alexander W. Williamson," Annals of Science , 31 (1974), 95-130. [BACK]

6. Williamson, "Theory of Aetherification," Philosophical Magazine , [3] 37 (1850), 350-356, reprinted in Papers on Etherification and on the Constitution of Salts (Edinburgh: Alembic Club Reprint no. 16, 1902), pp. 5-17. [BACK]

7. Williamson, "Theory of Aetherification," and more explicitly in "On the Constitution of Salts," JCS , 4 (1851), 350-355, reprinted in Papers , pp. 41-49 (on pp. 45-47). For a discussion see Colin A. Russell, History of Valency (Leicester: Leicester Univ. Press, 1971), pp. 50-54. [BACK]

8. Williamson, "Note on the Decomposition of Sulphuric Acid by Pentachloride of Phosphorus," Proceedings of the Royal Society , 7 (1854), 11-15. Williamson mentioned this paper and its results in a letter dated 10 March 1854 to Henry Roscoe, then in Heidelberg (Roscoe Collection). [BACK]

9. Gerhardt, "Remarques sur un travail de M. Hofmann sur les radicaux," Comptes rendus des travaux de chimie , 6 (1850), 233-236. [BACK]

10. Hofmann, "Note on the Action of Heat upon Valeric Acid," JCS , 3 (1850), 121-134. [BACK]

11. B. C. Brodie, "Observations on the Constitution of the Alcohol-Radicals, and on the Formation of Ethyl," JCS , 3 (1850), pp. 405-411, esp. p. 411. [BACK]

12. A. Wurtz, "Sur une nouvelle classe de radicaux organiques," Ann. chim. , [3] 44 (1855), 275-313. [BACK]

13. In an editorial note, Liebig mentioned Hofmann's priority when he printed a German summary of Wurtz' paper: "Über eine neue Klasse organi-

scher Radicale," Annalen , 96 (1855), 364-375 (on p. 365n.). Wurtz himself mentioned no predecessor other than Williamson. [BACK]

14. Wurtz, "Sur l'hydrure de cuivre," Ann. chim. , [3] 11 (1844), 250-252; Dumas, Traité de chimie appliquée aux arts , 1 (Paris, 1828), xxxviii. [BACK]

15. Wurtz, "Radicaux organiques," p. 306. [BACK]

16. Frankland, "Researches on the Organic Radicals," JCS , 3 (1850), 30-52 (on pp. 46-51); Hofmann, "Researches Regarding the Molecular Constitution of the Volatile Organic Bases," PTRS , 140 (1850), 93-131 (on pp. 93 and 95-97); Wurtz, "Mémoire sur une série d'alcaloides homologues avec ammoniaque," Ann. chim. , [3] 30 (1850), 443-507 (on pp. 444-445 and 501-502); Williamson, ''Theory of Aetherification," reprint p. 14. [BACK]

17. Gerhardt to Liebig, 18 October 1850, in C. Gerhardt, Jr., and E. Grimaux, Charles Gerhardt: Sa vie, son oeuvre, sa correspondance 1816-1856 (Paris: Masson, 1900), pp. 202-203 and 241; Liebig's letter is excerpted in Tiffeneau, ed., Correspondance , 2 , 121. [BACK]

18. Frankland, "On a New Series of Organic Bodies Containing Metals," PTRS , 142 (1852), 417-444 (on p. 441). [BACK]

19. Wurtz, "Radicaux organiques," pp. 308-313. [BACK]

20. A. W. Hofmann, "Life-Work of Liebig," in Zur Erinnerung an vorangegangene Freunde , 3 vols. (Braunschweig: Vieweg, 1888), 1 , 195-305 (on p. 273); Hofmann to Liebig, 10 May 1852, in Brock, LHB , p. 132. [BACK]

21. Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. For Liebig's indifference to theory, cf. Liebig to Wöhler, 15 April 1857, 27 February 1865, and March 1870, in Hofmann, LWB , 2 , 42, 179, and 280; also Kolbe to Vieweg, 16 March 1850, 18 April 1854, and 24 October 1859, VA 26, 74, and 153. [BACK]

22. See Kolbe to Vieweg, 9 April 1860, VA 157. [BACK]

23. See Erdmann to Gerhardt, 4 February 1855, in Grimaux, Gerhardt , p. 265. Erdmann had taken Gerhardt into the editorial board of the Journal für praktische Chemie at the beginning of 1852. When the first installment of Kolbe's Lehrbuch appeared, Erdmann protested loudly in a letter to Kolbe, which is not preserved (see Kolbe to Vieweg, 1 July 1854, VA 80). After Kolbe transferred to Leipzig, their relationship improved greatly. [BACK]

24. A. Strecker, "Über einige Verbindungen der Milchsäure," Annalen , 91 (1854), 352-367; Will referred to Strecker as a convert in 1854: Annalen , 91 , 265. See also Kolbe to Vieweg, 3 May and 1 June 1856, 20 February 1857, and 15 April 1860, VA 118, 119, 123, and 158. For Strecker's participation in Karlsruhe, see R. Anschütz, August Kekulé (Berlin: Verlag Chemie, 1929), 1 , 680 and 686-687. See also R. Wagner, "Adolph Strecker," Berichte , 5 (1872), 125-131. [BACK]

25. H. Kopp, "Über die specifischen Volume flüssiger Verbindungen," Annalen , 92 (1854), 1-32 (on pp. 24 and 28); Jahresbericht über die Fortschritte der Chemie , 7 (1854), 370-373; ibid., 10 (1857), 269-270; ibid., 13 (1860), 218-222; Kolbe to Vieweg, 1 July and 23 October 1854, VA 80 and 87; Kopp, Die Entwickelung der Chemie in der neueren Zeit (Munich: Oldenbourg, 1873), pp. 750-753 and 763. That Kopp as well as Will taught the reformed chemistry while Volhard was a student at Giessen (1852-1855) is stated in Vorländer, "Jacob Volhard," Berichte , 45 (1912), 1855-1902 (on pp. 1860-1861). [BACK]

26. F. Wrightson, "On the Atomic Weight and Constitution of the Alcohols," Philosophical Magazine , [4] 6 (1853), 88-99. [BACK]

27. Liebig's editorial notes to' Williamson, "Über Aetherbildung," Annalen , 81 (1851), 73-87 (on pp. 73n. and 76n). [BACK]

28. Williamson, "Note on the Preparation of Propionic and Caproic Acids," Philosophical Magazine , [4] 6 (1853), 204-206. Williamson later stated that he had tried in vain to talk Wrightson out of publishing the paper ( JCS , 7 [1854], 122). Williamson and Wrightson had first met in Liebig's laboratory in Giessen in the late 1840s. [BACK]

29. Wrightson, "Remarks on Professor Williamson's Othyle Theory," Philosophical Magazine , [4] 6 (1853), 418-420. [BACK]

30. Kolbe to Vieweg, no date, but 16 October 1853 by context, VA 59. [BACK]

31. Kolbe, "Kritische Bemerkungen zu Williamson's Wasser-, Aether- und Säure-Theorie," Annalen , 90 (1854), 46-61; "Critical Observations on Williamson's Theory of Water, Ethers, and Acids," JCS , 7 (1854), 111-121. [BACK]

32. Henry Watts to H. E. Roscoe, no date, but February 1854 by context, Roscoe Collection. [BACK]

33. Williamson to Roscoe, 9 February 1854, Roscoe Collection. [BACK]

34. Williamson, "On Dr. Kolbe's Additive Formulae," JCS , 7 (1854), 122-139; "Über Kolbe's chemische Formeln," Annalen , 91 (1854), 201-228. [BACK]

35. Williamson, "Kolbe's Formulae," pp. 123 and 132-135. When Kolbe visited London fourteen years later, he was graciously and warmly received by Williamson. In 1881, in the context of a violent diatribe against all of his scientific foes from Dumas to Baeyer, Kolbe mentioned his respect and affection for the Englishman, claiming that their earlier disagreement had been due to a mere misunderstanding ( JpC , 131 [1881], 311n.). [BACK]

36. Gerhardt, "Über Wasser-, Aether- und Säure-Theorie," Annalen , 91 (1854), 198-200.

37. Ibid. [Liebig, editorial note], p. 199n. [BACK]

36. Gerhardt, "Über Wasser-, Aether- und Säure-Theorie," Annalen , 91 (1854), 198-200.

37. Ibid. [Liebig, editorial note], p. 199n. [BACK]

38. Frankland, "Organic Bodies"; "Über eine neue Reihe organischer Körper, welche Metalle enthalten," Annalen , 85 (1853), 329-373. [BACK]

39. Kolbe, Lehrbuch , 1 , 12-14 (the first installment consisted of pp. 1-176).

40. Ibid., pp. 14-18.

41. Ibid., pp. 20-22, 24, and 43-44. Cf. Kolbe, "Notiz über das Cyanbenzoyl," Annalen , 90 (1854), 52-63, and "Über eine neue Bildungsweise des Benzoylwasserstoffs und die chemische Constitution der Aldehyde," Annalen , 98 (1856), 344-349. [BACK]

39. Kolbe, Lehrbuch , 1 , 12-14 (the first installment consisted of pp. 1-176).

40. Ibid., pp. 14-18.

41. Ibid., pp. 20-22, 24, and 43-44. Cf. Kolbe, "Notiz über das Cyanbenzoyl," Annalen , 90 (1854), 52-63, and "Über eine neue Bildungsweise des Benzoylwasserstoffs und die chemische Constitution der Aldehyde," Annalen , 98 (1856), 344-349. [BACK]

39. Kolbe, Lehrbuch , 1 , 12-14 (the first installment consisted of pp. 1-176).

40. Ibid., pp. 14-18.

41. Ibid., pp. 20-22, 24, and 43-44. Cf. Kolbe, "Notiz über das Cyanbenzoyl," Annalen , 90 (1854), 52-63, and "Über eine neue Bildungsweise des Benzoylwasserstoffs und die chemische Constitution der Aldehyde," Annalen , 98 (1856), 344-349. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

42. Kolbe, Lehrbuch , 1 , 24-27.

43. Ibid., pp. 29-31.

44. Ibid., pp. 22-23.

45. Ibid., p. 35.

46. Ibid. pp. 40-41.

47. Ibid. pp. 41-43.

48. Ibid. pp. 49-53.

49. Ibid. pp. 51-52; Kolbe to Vieweg, 1 March 1853 [sic for 1854], VA 69. [BACK]

50. Hofmann, "Heinrich Will: Ein Gedenkblatt," Berichte , 23R (1890), 852-899 (on p. 857). [BACK]

51. Anschütz, Kekulé , 1 , 16-17, from a letter to Anschütz, date not cited but probably shortly after the turn of the century, from Reinhold Hoffmann. [BACK]

52. Volhard, Justus von Liebig (Leipzig: Barth, 1909), 1 , 351; Vorländer, "Volhard," pp. 1860-1861. [BACK]

53. Will, "Zur Theorie der Constitution organischer Verbindungen," Annalen , 91 (1854), 257-292. [BACK]

54. Hofmann, "Will," pp. 881-882; idem, Erinnerung , 3 , 249. [BACK]

55. Hofmann, Introduction to Modern Chemistry (London: Walton & Maberley, 1865), p. v; Schorlemmer to Roscoe, 5 November 1881, Roscoe Collection. [BACK]

56. Kolbe, "Radicale; Radicaltheorie," Handwörterbuch , 6 (1854), 802-807. The German summary of Wurtz' paper was "Über eine neue Klasse organischer Radicale," Annalen , 96 (1855), 364-375. See also Kolbe to Vieweg, 23 December 1855, 5 January 1856, and 20 February 1857, VA 113, 114, and 123. [BACK]

57. Frankland, Experimental Researches in Pure, Applied, and Physical Chemistry (London: J. van Voorst, 1877), pp. 147-148; Sketches from the Life of Edward Frankland (London: Spottiswoode, 1901), pp. 193-196. [BACK]

58. Kolbe, "Radicale." To be precise, Kolbe did not explicitly write that carbon has a maximum combining capacity of four, and he did not say that methyls "substitute" directly for the oxygen of carbonic acid. The argument continued to be phrased in terms of the copula theory. He was, however, quite clearly and consciously applying Frankland's law, which he now accepted, to carbon. [BACK]

59. Kolbe, "Über die chemische Constitution der elementaren Moleküle," JpC , 115 (1873), 119-126 (on pp. 124-125n.). [BACK]