[99] Le Stazioni Sperimentali Agrarie Italiane, February, 1891. [100] Journal of the American Chemical Society, Vol. 17, p. 43. [101] Vid. op. et loc. cit. supra. [102] L’Engrais, Tome 10, p. 65. [103] Journal of Analytical and Applied Chemistry, Vol. 5, p. 694. Zeitschrift für analytische Chemie, Band 18, S. 99. [104] Vid. op. cit. 92, p. 103. [105] Journal of the Chemical Society (Abstracts), Vol. 58, p. 1343. [106] Comptes rendus, Tome 114, p. 1189. [107] Vid. op. cit. 24 and 25. [108] Report communicated to author by W. G. Brown. [109] Chemisches Centralblatt, 1895, p. 562. [110] Wiley, Report on Fertilizers to Indiana State Board of Agriculture, 1882. [111] Proceedings of the Association of Official Agricultural Chemists, Atlanta, 1884, p. 19. Report of Indiana State Board of Agriculture, 1882, p. 230, and Proceedings of the Association of Official Agricultural Chemists, Atlanta, 1884, p. 30. Huston and Jones. (These gentlemen are now investigating all materials used as sources of phosphoric acid in fertilizers; their results here quoted are from unpublished work, and include but a small part of the work so far done.) American Chemical Journal, March, 1884, p. 1. Proceedings of the Association of Official Agricultural Chemists, Atlanta, 1884, p. 23. Ibid, p. 28. Ibid, p. 38. Ibid, p. 45. U. S. Department of Agriculture, Chemical Division, Bulletin No. 7, p. 18. Ibid, Bulletin No. 28, p. 171. Ibid, Bulletin No. 31, p. 100. Ibid, Bulletin No. 31, p. 99. [112] Manuscript communication to author. [113] Pamunky phosphate is the so-called “olive earth” found along the Pamunky river, in Virginia. It is almost all precipitated iron and aluminum phosphates, and the product is peculiar in that the iron is almost all in the ferrous condition. [114] In the work of T. S. Gladding only fifty cubic centimeters of citrate were used. [115] In the work of T. S. Gladding only fifty cubic centimeters of citrate were used. [116] Zeitschrift für analytische Chemie, Band 10, S. 133. [117] Lehrbuch der Düngerfabrication. [118] Bulletin 54, Purdue Agricultural Experiment Station, p. 4. [119] Vid. op. cit. supra, p. 7. [120] Runyan and Wiley; Paper presented to Washington Section of the American Chemical Society, April 11, 1895. [121] Bulletin 38, Chemical Division, U. S. Department of Agriculture, p. 16. [122] Chemiker Zeitung, 1895, S. 553. [123] Die Käuflichen Dungermittel Stoffe, dritte Auflage, 1889. [124] Wyatt, Phosphates of America, p. 128. PART SECOND. NITROGEN IN FERTILIZERS.