584 INDEX. 



PAGB 



Sedentary soils IXi I3) 4O 



Sedimentary rocks 47 ( 43 



Sediment deposited by Mississippi in Gulf 7 



Sediments, exhibition of, from physical analysis 95, 96 



number of, in physical analysis 93 



table of diameters and hydraulic values 94 



Seeds, germination of ^oq 



Semi-humid and semi-arid region 377, 397 



Serpentine ,g 



Sieves, use in physical analysis of soils 88 



Silica, absorption and secretion by plants 31 



and alumina, soluble ; quantitative relations 385 



solubility in water 3! 



soluble, retained in alkali soils 391 



Silicate minerals , x 



Silicates of soda and potash, soluble 31 



Silicon, abundance of, in rocks .xxxi 



Silicophile plants, a fiction 522 



Sinkholes 4, 



Soapstone ,5 



Soda in arid and humid regions 394 



Soda, nitrate of 66 



Sodium salts, leached out by drains and rivers 24 



Soil analysis, change of views regarding 317 



discrepant methods used in 402 



practical utility of 3^ 



Soil and subsoil, causes and processes of differentiation 120 



ill-defined 120 



Soil bacteria, numbers of 14! 



Soil character, recognition from native vegetation 487, 511 



Soil-dilution experiments 347 



fi S ures 343, 349, 350 



table of 350 



Soil-examination, short approximate methods for, used at California 



station 560 



summary directions for, in field or farm 556 



Soil-formation influenced by rainfall 22 



physical processes of I 



Soil-forming processes accelerated by high temperatures 398 



Soil-grains, number of 99 



surface of 99 



determination by air-flow 99 



by ' ' Benetzungswiinne " 99 



investigation, historical review of Hi^ 



moisture, regulation and conservation of 234 



phosphates, solubility in water ; Schloesing fils 332 



probe, mode of using 177 



profiles in arid and humid region 165 



