3 So 



INDEX 



Minerals, composition of rock-form- 

 ing, 17 



Mitscherlich on benetzungs-warme, 

 98 



Molecular forces, 77 



Molisch on iron bacteria, 239 



Moor-band pan, 25 



Moore, cultivation of nodule organ- 

 isms, 208 



Mould, 196 



Mulches, 108, 115, 284 



Miiller on nitrification, 218 



Mycorhiza, 240, 321 



NatroliTE, 27 



Nile water, 287 



Nitragin, 208 



Nitrates, determination of, 168 ; for- 

 mation of, 116. 218 ; in drainage 

 waters, 262 ; in soil, effect of 

 cultivation on, 223 ; produced by 

 bare fallow, 125, 225 



Nitrification, 218 



Nitrogen, determination of, 164 ; 

 fixation of, 199, proportion re- 

 covered in crop, 228, 230 



Nobbe on nitragin, 207 



Nodules on leguminous plants, 205 



O'EMLER on specific heat of soil, 



147 



Olivine, 23 



Optimum proportion of water in 

 soils, for growth, 75, 89 ; tem- 

 peratures for growth, 140 



Orchids, germination of, 244 



Osborne on mechanical analysis of 

 soils, 56 



Osmosis, entry of plant food by, 

 178 



Packing of soil particles, 6fi 



Pan, iron, in soils, 25, 319, 329 



Paring and burning, 302 



Parkes on temperatures of drained 

 and undrained land, 149 



Peat, origin of, 48, 197, 199 ; recla- 

 mation of, 298 ; soils, 332 



Percolation, 81, 128 ; through 

 gauges at Rolhamsted, 85 



Phosphoric acid, determination of, 

 166, 184 : retention by soil, 256 



Pipe clays, 39 



Pipes in chalk rock, 24 

 Plasmodiophora brassicse, 240, 244 

 Plasticity of clay, 38 

 Ploughing, damage done by deep, 



30, 329 

 Pore space, 68 

 Potash, determination of, 166, 17c ; 



origin in soils, 20, 29 ; retention 



by soil, 253 

 Potatoes grown on different soils, 



value of, 1 

 Protein in wheat, 158 

 Protozoa in soil, 194, 232, 303 

 Pseudomonas radicicola, 205, 207 



Quality of produce from early and 



late soils, 157 

 Quarry water, 11 

 Quartz, 17 

 Quincke on range of molecular 



forces, 77 



Radiation, 143 



Rainfall and crops, 102 



Rainfall and drainage, 85, 128 



Recovery of manures in crop, 185, 

 230 



Red lands of Dunbar, value of 

 potatoes from, 1, 62 



Richthoven on loess deposits, IO 



Rock-forming minerals, 17 



Rolling, effect of, 118 



Roots, solvent action of, 179 ; 

 weathering action of, 14 



Rothamsted, available constituents 

 in soil of, 173 ; bare fallows at, 

 126 ; composition of drainage 

 waters at, 259 ; composition of 

 soil, 4T, 63 ; drain-gauges at, 85 ; 

 drought of 1870 at, 1 21 ; investi- 

 gations on fixation of nitrogen at, 

 201, 216 ; lime in soil of, 252 ; 

 losses of nitrogen in manure at, 

 230 ; method of sampling soils 

 at, 53 ; nitrates in soil at, 215 ; 

 phosphoric acid in soil of, 184, 

 258; potash in soil of, 254; 

 weights of soil at, 71 



Russell, protozoa in soil, 232 



Rutile, 37 



Sachs on solvent action of roots, 

 179; on temperature and tran- 



