Chapter V

Von Bemmelén, determination of water, 310
method of humus estimation, 332

Vegetable life, action, 48
soils, 58–60

Volatile matter, estimation, 455

W

Wahnschaffe, preliminary treatment of samples, 91

Warington, absorption of potash and ammonia, 120
and Peake, oxidation of carbon, 316
experiments in nitrification, 468–470, 485–488
indigo method, 528–531
Schloesing method, 505–508

Water absorption by soils, determination, 136–143
capacity of soils, effect of pressure, 143
determination at 110°, 306
general conclusions, 313
estimation after air drying, 305
in water-free atmosphere, 149
in fresh samples, 304
soils, determination, 303–314
movement, causes, 155
in soils, 151–169
methods, 151
relative flow, 159
residual amount, dried at 110°, 308
solvent, action, 47
for soils, 343
special examination, 576–583
total solid matter, 576

Way, absorptive power of soils, 118, 120

Weight of soil, 102

Welitschowsky, measurement of percolation, 161–163

Wheeler and Hartwell, analysis of sea-weeds, 13

Whitney and Marvin, method of determining soil temperatures, 112–115
causes of water movement, 155
determination of interstitial space, 134
effect of potential, 172
influence of surface area on absorption, 123
measurement of percolation, 163
relative flow of water, 159
surface tension of fertilizers, 156
theory of subsidence, 180

Williams, machine for mineral sections, 267
-Warington method for nitric acid, 540, 541

Winogradsky, experiments in nitrification, 471–483

Wolff and Wahnschaffe, method of determination of water absorption, 136
determination of coefficient of evaporation, 148
method for silt analysis, 192
preliminary treatment of soil samples, 88

Wollny, determination of water absorption, 142
occurrence of carbon dioxid, 282

Wülfing’s apparatus, 277

Wyatt, phosphate deposits, 8