306 



INDEX 



Capillarity, 72 ; supply of water to 



crop by, 97, 106. 

 Carbon, determination of, 143. 

 Carbon to nitrogen in soils, ratio 



of, 46. 

 Carbonic acid in soil gases, 13 ; 



excreted by roots, 158 ; and water, 



action on rock minerals, 13. 

 Catch crops, no. 

 Chalk, 41; "pipes" in, due to 



weathering, 23; soils, 281. 

 Chalking, 261. 



Chemical analysis of soil, 139. 

 China clay, 19, 35. 

 Chlorosis, 283. 

 Citric acid as solvent in soil analysis, 



159. 



Clay, colloid, 35 ; flocculation of, 

 38 ; impermeability to water, 34, 

 71 ; nature of, 36, 52 ; origin of, 

 19 ; shrinkage on drying, 34, 284 ; 

 soils, 30, 283. 



Claying, 256. 



Cleopatra's Needle, weathering of, 

 n. 



Climate and situation, 136. 



Clostridium Pastorianum, 187. 



Club root in turnips, 204, 208. 



Cohesion due to surface tension, 82. 



Colloid clay, 35. 



Colmetage, 255. 



Colour of soils, 27; and temperature, 

 127. 



Condensation of water by soil, 87. 



Condition of land, 233. 



Conventions necessary in chemical 

 analysis of soil, 141. 



Crops, plant food removed by, 152. 

 , Crops, water required by, 91, 108. 

 ** Cultivation, effect of, on water con- 

 tent of soil, 95, 101, 104. 



rounded by running water, 17 ; 

 weathering of felspar, 19. 



Deflocculation, 39, 252. 



Defoe, definition of manure, 154. 



Deherain on available phosphoric 

 acid in soils, 158 ; nitrates in 

 drainage waters, 228 ; nitrifica- 

 tion, 195. 



Deherain and Maquenne on denitri- 

 fi cation, 198. 



Denitrification, 197. 



Density of soils, 63. 



Drainage, 92 ; required with irriga- 

 tion, 249 ; warms the land, 1 32 ; 

 waters, composition of, 222. 



Drains, flow of, 77. 



Drain-gauges, 78 ; flow greater than 

 rainfall, 87. 



Drift, glacial, 15 ; maps, 297; soils, 8. 



Drought of 1870 at Rothamsted, 

 108. 



Drought, susceptibility of different 

 soils to, 99. 



Drying effect of crops, 86, 108. 



Dunbar, potato soils of, 1. 



Dung, effects on water in soil, 117; 

 and denitrification, 201. 



Dyer on determination of available 

 phosphoric acid and potash, 1 59 ; 

 potash and phosphoric acid re- 

 tained by Rothamsted soils, 218. 



Early and late soils, 135. 

 Ebelmar on weathering of basalt, 2 1. 

 Egypt, irrigation in, 248. 

 Eremacausis, 170. 

 Evaporation, cooling effect of, 1 30 ; 



losses of water by, 97. 

 Exhausting effect, of nitrate of soda, 



253 ; of wheat, 237. 



DARWIN on action of earthworms, 



14. 

 Daubree on size of sand grains not 



Fairy rings, 239. 

 Fallows, bare, 86, 112. 

 Felspar, 18. 



