348 



INDEX 



Chemical analysis of soil, 159 



China clay, 20, 39 



Chlorosis, 327 



Citric acid as solvent in soil analysis, 

 181 



Clay, colloid, 39 ; flocculation of, 

 42 ; impermeability to water, 38, 

 76 ; nature of, 44, 57 ; origin of, 

 20 ; shrinkage on drying, 38, 

 328; soils, 65, 327 



Claying, 296 



Cleopatra's Needle, weathering of, 

 n 



Climate and situation, 158 



Clostridium Pastorianum, 212 



Club root in turnips, 240, 244 



Cohesion due to surface tension, 91 



Colloids, 39, 50, 249 



Colmetage, 295 



Colour of soils, 28 ; and tempera- 

 ture, 144 



Condensation of water by soil, 98 



Condition of land, 271 



Conventions necessary in chemical 

 analysis of soil, 161 



Crops, plant food removed by, 172 



Crops, water required by, 101, 121 



Crowstone, 25, 329 



Cultivation, effect of, on water con- 

 tent of soil, 106, 114, 118 



DARWIN on action of earthworms, 



H 



Daubree on size of sand grains not 

 rounded by running water, [8 ; 

 weathering of felspar, 20 



Deflocculation, 45, 283, 292 



Defoe, definition of manure, 174 



Deherain on available phosphoric 

 acid in soils, 180; nitrates in 

 drainage waters, 265 ; nitrifica- 

 tion, 223 



Deherain and Maquenne on denitri- 

 fication, 226 



Denitrification, 226 



Density of soils, 69 



Drainage, 103 ; required with irriga- 

 tion, 288 ; warms the land, 1 49 ; 

 waters, composition of, 258 



Drains, flow of, 84 



Drain-gauges, 85, III ; flow greater 

 than rainfall, 91 



Drift, glacial, 16 ; maps, 341 ; soils, 8 



Drought of 1870 at Rothamsted, 

 121 



Drought, susceptibility of different 

 soils to, 113 



Dry farming, 129 



Drying effect of crops, 121, 130 



Dunbar, potato soils of, I 



Dung, effects on water in soil, 131 ; 

 and denitrification, 228 



Dyer on determination of available 

 phosphoric acid and potash, 181 ; 

 potash and phosphoric acid re- 

 tained by Rothamsted soils, 254 



Early and late soils, 154 

 Ebelmar on weathering of basalt, 21 

 Egypt, irrigation in, 287 

 Eremacausis, 195 

 Evaporation, cooling effect of, 147 ; 



losses of water by, 109 

 Exhausting effect, of nitrate of soda, 



292 ; of wheat, 275 



Fairy rings, 278 



Fallows, bare, 96, 125, 130, 225, 328 



Felspar, 19 



Fen land, potatoes from the black 



soils of, 2 : reclamation of, 298 

 Fertility, 271 

 Film of water surrounding soil 



particles, 78 

 ' Finger-and-toe," 240, 244, 281 

 Fixation of nitrogen, 199 

 Flint, 18 



Flocculation of clay, 42, 45, 283 

 Flow of water through soils, 75 

 Frank on mycorhiza, 241 

 Frosts in valleys, 152 ; killing effect 



of, 141 

 Fruit trees in grass land, 123 

 Fuller's earth, 41 

 Fungi in the soil, 192, 239, 278 



Gayon and Dupetit on denitrifica- 

 tion, 227 

 Germination, temperatures of, 142 

 Glacial drift, 16 

 Glauconite, 27 

 Granite, weathering of, 19 

 Gravel, 15 



Green manuring, 210 

 Greenhouse soils, 237 

 Greenstone, weathering of, 22 





