[82] See Historical Introduction, pp. 40-45.
[83] The evidence demonstrating this is to be found in the fact that the amount of carbon found in different soils rises or falls in proportion to the nitrogen. See p. 126.
[84] See Chapter IV. on Nitrification.
[85] Diffusion as well as capillary attraction is a means of bringing nitrates again to the surface-soil after rain.
[86] See Appendix, Note VI., p. 158, and Note VIII., p. 160; also p. 154.
[87] See Appendix, Note VII., p. 159.
[88] See following Chapter on Nitrification, p. 178.
[89] According to the Agricultural Returns for 1888, the number of cows in milk in Great Britain amounted to 2,450,444. If we multiply this number by 22 the result is 54,000,000 lb., or in tons 24,107. This quantity represents 154,067 tons of ordinary commercial nitrate of soda.
[90] For 1878 (p. 146 et seq.) The reader interested in the subject is referred to the paper itself.
[91] In tons 4464, and represents 28,530 tons of nitrate of soda.