INDEX 



491 



Siderite, 154. 

 Silage, 348, 385- 

 Silica, 152. 



function in plants, 16. 

 Silicates, hydrated, 149, 152. 

 Silt, 80. 



Soda, not essential, 16. 

 Soil, adhesion in, 115. 

 Soil acidity, 160, 250, 253. 



air space, 115. 

 Soils, alluvial 56, 66, 76. 

 Soil analysis, 167. 



apparent specific, gravity, 113. 



by strong acids, 161. 



interpretation, 173, 195. 

 Soil atmosphere, 51. 



arid, 178. 



Soil bacteria, 204, 206. 

 Soil carbon dioxide of, 5 1 - 



carbonate of lime in 154, 186. 



chloroform extract of, 157. 



chemical composition, 167. 



relation to adaptation to crops, 

 II. 



classification, 85, 95, 117. 



cohesion, 115. 



color, 112. 



complete analysis, 168. 



colluvial, 63. 



constituents, 149. 



crumbs, 90. 



cumulose, 63. 



deficiencies, 174, 244, 245. 



depth, 102. 



depth limitations of, ic6. 



effects of manure on, 290. 



ether extract of, 157. 



extract, composition, 182. 



fertility of, relation to composi- 

 tion, 171. 



relation to water, 123. 

 Soil, fixation in, 234, 239. 



from igneous rocks, 63. 



Soil, from rocks, 54. 

 glacial, 57, 68, 76, 97. 

 investigation of minerals of, 155. 

 limestone, 73, 76, 90, 97. 

 maps, 99. 

 losses and gains of, 61, 76, 271, 



341. 



mechanical composition, 86. 

 mechanical analysis, 79. 

 minerals, 147. 

 minerals, solubility, 183. 

 muck, 74. 

 organic matter, 156, 228. 



ammonia-soluble, 162. 

 particles, relation to texture, 83. 

 particles, 79. 

 peat, 74. 



pentosans in, 157. 

 physical properties, 101. 

 provinces of the U. S., 74- 

 quantity of water in, 127. 

 retention of water by, 134. 

 sedentary, 61. 

 series, 94. 

 shrinking of, 117. 

 specific gravity, 113. 

 survey, 99. 

 solutions, 199. 

 temperature, 107, no, in. 

 texture and composition 87. 

 toxic theory of, 158. 

 transported, 61. 

 types, 94- 



types, composition, 179. 

 ventilation, 51. 

 water, 132, 136, 138. 

 water control, 147. 

 water losses, 142. 

 water gains, 139. 

 water and transpiration, 121. 

 weathering, 61. 

 water in, 132. 

 water-soluble part, 196. 



