INDEX. 



585 



PACK 



Soil, samples, directions for taking, by Calif. Station 553 



sedentary or residual n, 13, 40 



study, qualifications needed for 524 



surveys, early, of Kentucky, Arkansas and Mississippi 316 



temperature, annual range near surface in arctic and tropical regions 303 



change with depth ; table 303 



influence of evaporation on 307 



influence of soil material 306 



influence of surface conditions, 303 



influence of vegetation and mulch 305 



tests by crop analysis, Godlewski, Vanderyst 337, 338 



by extraction with organic acids ; Dyer, Maxwell 339 



water, different conditions of 195 



Soils, acid-soluble and water-soluble portions most important 324 



alluvial 12, 13 



ancient, in geological formations xxix 



calcareous, definition of 367, 496, 524 



classification of, figure II 



colluvial 12, 24 



definition of xxix 



derived from various rocks 49 



effects of crusting on 221 



indefinite action of dilute acids on 326 



interpretation of analyses ; Wohltmann 403 



physico-chemical investigation of 313 



(see Table of Contents) 



Solar radiation, influence of 302 



Solubility, continuous, of soils in water 328 



King's table, rich and poor soils 330 



Schultze's table, rich soil 328 



Ulbricht's table, poor soil 329 



Solvent action of water upon soils 3 2 7 



power of water 17 



Solubility, increased with nitrogen-content 141 



Sour grasses 123 



humus, antiseptic properties of 122 



soils 122 



Souring of soils, by cultivation 123 



Stable or farmyard manure 7 2 



composition of, table 73 



green-manuring only substitute 74 



method of using, in humid region 74 



physical effects of 73 



use of, in the arid region 74 



Stalactites and stalagmites 4 1 



Stassfurt Salts, discovery of 69 



importance to agriculture 7 



origin of 7 



