INDEX 



309 



Peat, origin of, 43, 174 ; reclamation 



of, 258 ; soils, 288. 

 Percolation, 75, 115; through 



gauges at Rothamsted, 78. 

 Phosphoric acid, determination of, 



146 ; retention by soil, 219. 

 Pipe clays, 35. 

 Pipes in chalk rock, 23. 

 Plasmodiophora brassicae, 204, 208. 

 Plasticity of clay, 34, 40. 

 Ploughing, damage done by deep, 



29, 285. 

 Pore space, 60. 

 Potash, determination of, 146, 150; 



origin in soils, 19, 28 ; retention 



by soil, 217. 

 Potatoes grown on different soils, 



value of, t. 

 Pseudomonas radicicola, 180, 182. 



Qqality of produce from early and 



late soils, 137. 

 Quarry water, 1 1. 

 Quartz, 17. 

 Quincke on range of molecular 



forces, 71. 



Radiation, 126. 



Rainfall and crops, 91. 



Rainfall and drainage, 115. 



Recovery of manures in crop, 164. 



Red lands of Dunbar, value of 

 potatoes from, 1. 



Richthoven on loess deposits, 10. 



Rock-forming minerals, 16. 



Rolling, effect of, 105. 



Roots, solvent action of, 158 ; 

 weathering action of, 14. 



Rothamsted, available constituents 

 in soil of, 162 ; bare fallows at, 

 114 ; composition of drainage 

 waters at, 222 ; composition of 

 soil, 37. S 8 I drain gauges at, 78 ; 



drought of 1870 at, 108 ; investi- 

 gations on fixation of nitrogen at, 

 176, 178, 189 ; lime in soil of, 216; 

 losses of nitrogen in manure at, 

 201; method of sampling soils at, 

 48 ; nitrates in soil at, 196 ; phos- 

 phoric acid in soil of, 162, 22 1; 

 potash in soil of, 218 ; weights of 

 soil at, 64. 

 Rutile, 34. 



Sachs on solvent action of roots, 

 158; on temperature and tran- 

 spiration, 124 ; on water in soil, 

 when plants wilt, 84. 



Salfeld on soil inoculation, 185. 



Salt, causing sterility, 244 ; marshes, 

 vegetation of, 279. 



Salts, soluble in soils, 147. 



Sampling of soils, 47. 



Sand, origin of, 17, 33 ; velocity of 

 current required to carry, 33. 



Sandy soils, 30, 242, 274. 



Saturation of soils by water, 69, 77. 



Saussure" on theory of nutrition, 175. 



Schloesing on colloid clay, 35 ; on 

 mechanical analysis of soils, 50. 



Schloesing and Muntz on nitrifica- 

 tion, 191. 



Schloesing/?/* on fixation of nitrogen, 

 181. 



Schneidewind on denitrification, 200; 

 on fixation of nitrogen, 186. 



Schultz on green manuring, 185. 



Sea, effect on climate, 1 36. 



Sedentary soils, 7. 



Selenite, 24, 26, 285. 



Senft on decomposition of felspar, 

 19. 



Serpentine, 22. 



Sewage farms, crops on, 92 ; purifi- 

 cation of, by soil, 213. 



Shingle, growth of vegetation on, 

 10. 



