^{page 499 note 1} Varro, , Rerum Rusticarum, lib. I. cap. 13.Google Scholar

^{page 499 note 2} Columella, , Rerum Rusticarum, lib. II. cap. 15: “With bottom shelving in the manner of ponds, well built and paved, that the moisture shall not pass through, for it is of great importance that the dung retain its strength by the juice of it not being dried up.”Google Scholar

^{page 500 note 1} The Whole Art of Husbandry, by Esq, J. M. F.R.S., 1707, p. 96Google Scholar. In later editions the author gives his full name.

^{page 501 note 1} Ellis, Wm, The Modern Husbandman, for the month of 11, pp. 67 et seq. in the 1743 edition.Google Scholar

^{page 501 note 2} James, Donaldson, Modern Agriculture, or the present state of husbandry in Great Britain, 1796, pp. 26. 245 et seq.Google Scholar

^{page 501 note 3} Eighteen to twenty-four cartloads, each containing 16 to 18 cwt., per statute acre, according to Donaldson.

^{page 501 note 4} These papers are summarised by Young in his interesting “Essay on Manure,” Bath Soc. Papers, vol. X. 1804. See also Young’s Farmer’s Calendar, Art. Manure.Google Scholar

^{page 501 note 5} Quoted in Boussingault, Economie Rurale, 2nd edition, 1851, vol. I. p. 707.Google Scholar

^{page 501 note 6} Voelcker, A., Journ. Roy. Agric. Soc. 1856, 17, 191–260.Google Scholar

^{page 502 note 1} Thaer, A. von, Grundsatze der raliondlen Landwirtschaft, 1810, Bd. 2, pp. 87 et seq.Google Scholar The experiments are described in a paper by Thaer and Einhof entitled “Versuohe und Beobachtungen über die Excremente vom Hornvieh, und ihre Fäulniss,” published in Hermbstädt Archiv der Agricullurchemie, 1804, 1, 255–304.Google Scholar Nothing illustrates more vividly the enormous strides made by agricultural chemistry during the period 1804 to 1840 than a comparison between this and Boussingault’s papers.

^{page 502 note 2} Economie Rurale. Boussingault thought that some of the nitrogen was actually exhaled: it was not till physiologists had proved this not to be the case that the full value of his work was appreciated.

^{page 503 note 1} Their last paper on the subject summarises their work and that of the other investigators up to that time. Journ. Roy. Agric. Soc. 1895, pp. 47–146.

^{page 503 note 2} Beiträge zur Begründung einer rationellen Fütterung der Wiederkäuer, Heft 1, 1860.Google Scholar

^{page 503 note 3} Maercker, and Schneidewind, , Landw. Jahrbücher, 1898, 27, 215–40Google Scholar

^{page 504 note 1} Schattenmann, , Annales Chim. Phys. Series 3, vol. IV. p. 358.Google Scholar The work is also quoted in Boussingault’s Economie Rurale, 2nd edition, vol. I. p. 701.Google Scholar

^{page 504 note 2} Annales Agronomiques, 1884, 10, 289–301.Google Scholar

^{page 504 note 3} Landw. Versuchs-Stat. 1897, 48, 247–360.Google Scholar

^{page 504 note 4} Landw. Versuchs-Stat. 1897, 48, 189–245.Google Scholar

^{page 504 note 5} Landw. Jahrbücher, 1898, p. 215.Google Scholar

^{page 507 note 1} West of Scot. Bull. No. XIV. 1914.Google Scholar

^{page 507 note 2} Leeds Bull. No. 90, p.9.Google Scholar

^{page 510 note 1} Journ. Roy. Ac. Soc. 1913, 74, 410.Google Scholar

^{page 515 note 1} See Journ. Boy. Agric. Soc. 1902, 63, 85–87.Google Scholar

^{page 515 note 2} Berry, , West of Scot. Bull. No. XIV. 1914.Google Scholar

^{page 515 note 3} Wood, , This Journ, 1907–1908, 2, 207.Google Scholar

^{page 515 note 4} Journal S.E. Agric. Coll. 1905, No. 14, 187.

^{page 522 note 1} “The Simpler Natural Bases.” Barger, G., Longman’s Monographs on Biochemistry, 1914.Google Scholar

^{page 523 note 1} See “The Physiology of Protein Metabolism,” Cathcart, , Longman’s Biochemical Monographs, 1912, pp. 49–55.Google Scholar

^{page 523 note 2} E.g. Brasch, and Neuberg, , Biochem. Zeit. 1908, 13, 299; and 1909, 22, 403.Google Scholar Neuberg, ibid. 1909, 18, 424 et seq. and 1909, 20, 450 et seq. Borchardt, , Zeit. f. physiol. Chem. 1909, 59, 96.CrossRefGoogle Scholar

^{page 523 note 3} Dakin, , J. Biol. Chem. 1908, 4, 63.Google Scholar

^{page 523 note 4} Ehrlich, , Zeitsch. Verrein Rübenzucker Ind. 1905, 539–67.Google Scholar

^{page 523 note 5} Biochem. J. 1917, 11, 71.CrossRefGoogle Scholar

^{page 524 note 1} Bienstock, , Archiv f. Hygiene, 1899, 36, 355–89; 1901, 39, 390–427.Google ScholarRettger, L. F.J. Biol. Chem. 1906, 2, 71–86; 1907, 4, 45–55; and 1912, 13, 341–46.Google Scholar

^{page 524 note 2} See Barger, , loc. cit. p. 8.Google Scholar

^{page 525 note 1} McGowan, , Houston, , Frye, and Kershaw, , Royal Commission on Sewage Disposal. 5th Report, Appendix IV. 1910, pp. 249–51.Google Scholar

^{page 526 note 1} McGowan and Frye, ibid. pp. 52–72.

^{page 527 note 1} Thus the losses on the addition of tap-water were:

The figures are all shown as per 100,000 of sewage but as the volume of sewage did not change they are proportional to the actual weights involved.

Some of the missing nitrogen in this case is to be found in the sludge which deposits each time the contact bed is filled.

^{page 527 note 2} Report to the Corporation of Belfast on the purification of the Belfast Sewage (Baird, Belfast, 1908). Also, 5th Report of the Sewage Commission, Appendix VI. pp. 171–94.

^{page 534 note 1} Verslag. Landbouwk. Onderzoek. Rijkslandbouwproefstat. No. 1, p. 21, 1907; No. 7, p. 106, 1910.

^{page 535 note 1} The glass spiral between B and C is to relieve the strain on the apparatus.

^{page 539 note 1} The manure was fresher and contained more straw than the last sample; its content of nitrogen was lower.

^{page 539 note 2} At first sight 20 c.c. may appear to be rather a large experimental error. It is however exceedingly difficult to get an accurate value for the initial and final volumes of air. The apparatus is in effect a volumenometer, and in addition to the difficulties inherent in this form, there is the further difficulty that the tension of aqueous vapour is not constant throughout, but is different in the flask from what it is in the reagent bulbs B or C, or the capacity bulb on the way back from the pump to the flask. These uncertainties cause errors in the initial and final amounts, and therefore still greater errors in the difference used in these calculations. The difference observed in the experiment on p. 538 is six times the error of the experiment.

^{page 542 note 1} Reiset, , Jahresbericht der Chemie, 1856.Google Scholar

^{page 542 note 2} Ville, , Recherches Expérimentales sur la Végétation, 1857.Google Scholar

^{page 542 note 3} Boussingault, , Ann. de Chim. et de Phys. (III.) 46, 1856, and Compt. Rend. 1858, 47 (see his collected works).Google Scholar

^{page 543 note 1} Lawes, Gilbert and Pugh, , Phil. Trans. 1861, 431–577, “On the sources of the nitrogen of vegetation.”Google Scholar

^{page 543 note 2} Angus, Smith, Memoirs Manchester Lit. and Phil. Soc. 1865, vol. XXII. (vol. II. of 3rd Series), 47–63; 1867, vol. XXIV. (vol. IV. of 3rd Series), p. 37; also Report to the Local Govt. Board, 1882.Google Scholar

^{page 543 note 3} Frankland, Denison and Chalmers, Morton, Royal Commission, Pollution of Rivers, 1868, vols. I.—IV.Google Scholar

^{page 543 note 4} Loc. cit. (see p. 527 above).

^{page 544 note 1} Comptes Rendus, 1882, 95, 644–46Google Scholar, and 1365–67: also Mémoires de la Soc. des Sciences physiques et naturelles de Bordeaux, 1886, Séries III. Vol. II.Google Scholar

^{page 544 note 2} Journ. f. Landw. 1894, p. 383.

^{page 544 note 3} Landw. Jahresbücher, 21, 317.Google Scholar

^{page 544 note 4} Pfeiffer, Th., Franke, E., Götze, C., Thurmann, H., “Beiträge zur Frage über die bei der Fäulnis stickstoffhaltiger organischer Substanzen eintretenden Umsetzungen,” Landw. Versuchs-Stat. 1897, 48, 189–245.Google Scholar

^{page 545 note 1} Thus Rumker, , Mitt. Landw. Instit. Breslau, 1909, 4, 853–872, “Zur Frage der Stallmistzersetzung,” directs attention to the great amount of nitrification that would be required if the whole of the nitrogen were lost by alternate nitrification and denitrification, and asks where the lime is to come from, apparently overlooking the fact that only a small amount is necessary as it could be used over and over again.Google Scholar

^{page 545 note 2} Journ. Soc. Chem. Ind. 1897, 16, 510.Google Scholar

^{page 545 note 3} Annales Instit. Agron. 1911, 10. 2nd series, 1–48.Google Scholar

^{page 547 note 1} Adeney, , Proc. Royal Irish Acad. 1905Google Scholar; also Royal Commission on Sewage Disposal, 5th Report, Appendix VI. 1908, pp. 13–20.Google Scholar

^{page 550 note 1} Journ. South-Eastern Agric. Coll. Wye, 1905, No. 14, 187.

^{page 551 note 1} For further experiments with horse manure see this Journal, 1917, 8. 299.Google Scholar

^{page 554 note 1} Journ. Roy. Agric. Soc. 1917, 77, 1–35.Google Scholar

^{page 556 note 1} Journ. Roy. Agric. Soc. 1917, 77, 1–35.Google Scholar

^{page 557 note 1} It is difficult to suggest anything wholly new in agriculture. An illustration of a manure pit can be seen in Hale's Compleat body of Husbandry, 1756, and another in an interesting pamphlet by Boussingault, La Fosse à Fumier, Paris, Béchet Jeune, 1858.