Index 



Physiological effect on tobacco 

 growth of: nitrogen, 348; 

 phosphorus, 356; i)otassium, 

 359. 



Phosphates, effect on protein con- 

 tent of wheat, 124. 



Phosi)horus, physiological effect 

 on tobacco, 357-359. 



Poppv, California, deep rooting, 

 186. 



Pot cultures with soils containing 

 copper, 432. 



Potash, effect on protein content 

 of wiieat, 125. 



Potash alum, effect on barley 

 growth, 503, 522, 561, 579- 

 581. 



Potassium, physiological effect on 

 tobacco, 359, 360. 



Potassium bicarbonates, chlorides, 

 sulfates, effects on soil col- 

 loids, 327, 328. 



Protein Content of Wheat, Stud- 

 ies upon Influences Affecting, 

 63. See also Wheat. 



Ps. fluroescens, culture experi- 

 ments, 142. 

 putida, culture experiments, 142. 



Pure cultures, ammonification by, 

 141; physiological efficiency, 

 141; experiments: organisms 

 selected, 142; organic ma- 

 terials, 142; method, 142; 

 analyses of soils, 143. See 

 also Cottonseed meal; Dried 

 blood; Guano; Nutrient solu- 

 tion; Peptone; Pot Cultures; 

 Sand; Water Culture. 



Eemy method, 4, 19. 



Eemy and Rosing, experiments on 

 soil bacteria, 128. 



Salts, effects on phenoldisulphonic 

 method of determining ni- 

 trates in soils, 21, 23-28; ef- 

 fects of kation, and of anion, 

 24, 32; tables of effects of: 

 NaCl, 25, Na,S04, 25, NaoCO,, 

 26, mixed alkali salts, 28; dif- 

 ference in behavior of Na.,S04 

 and NaoCOj, 26; comparison 

 of effects of NaCl, KCl, 

 MgCL, 32, 33; effects of dry 

 mixing of nitrates and salts, 

 34; cylinder experiment on 

 physiological effects on crop 

 plants, 294; vertical distri- 

 bution in cylinders, 296; ef- 

 fects on absorption of water 

 by soils, 301 ; fertilizer, and 

 deflocculation, 336; neutral, 

 agents forming diffusible col- 



lodial matter, 317, 318; ab- 

 sorption by plants from nutri- 

 ent solution, 366. 



Sand as a culture medium, 344; 

 influence of nutrient solution 

 on plants grown in, 341. 



Sarcina lutea, culture experi- 

 ments, 142. 



Sharp, L. T., 275, 291. 



Shaw, G. W., 63. 



Smelter Wastes, Solid, Experi- 

 ments on the Effects of Con- 

 stituents of, on Barley Growth 

 in Pot Cultures, 495. 



Snyder, H., cited on humification, 

 175. 



Sodium, absorption of, cause of 

 deflocculated condition of 

 salt-treated soils, 315; chem- 

 ical studies of, 310; repre- 

 sented in salt-treated soils by 

 calcium and magnesium, 311. 



Sodium bicarbonate, effect on soil 

 colloids, 322, 323. 



Sodium carbonate, cylinder ex- 

 periment on physiological ef- 

 fects on crop plants, 294; de- 

 flocculating agent, 291 ; eft'ect 

 on: nitrate determination, 26, 

 28, 36, 37, soil colloids, 322, 

 323; soil suspensions, not the 

 same as effect of NaOH, 304; 

 soils treated with, 296. 



Sodium chloride, application to 

 soil increases calcium and 

 magnesium in percolate, 310; 

 physiological eft'ects on crop 

 plants, 294; effect on: nitrate 

 determination, 25, 28, 36, floc- 

 culation of collodial matter 

 by varying concentrations, 

 309; soil's, 296. 



Sodium hydroxide, effect on: soil 

 colloids, 322, 323, soil suspen- 

 sions, different from that of 

 Na,CO„ 304. 



Sodium salts, effects on collodial 

 matter, 316, 327, 328. 



Sodium silicate, present in col- 

 loidal matter, 325. 

 Sodium sulfate, physiological ef- 

 fects on crop plants, 294; ef- 

 fect on: nitrate determina- 

 tion, 25, 28, 33, 36, 37, soils, 

 296. 

 Soil, bacteria, 129; bacteriology, 

 141; deflocculation, 315, 318, 

 324; diffusion, 313, 315; man- 

 agement, 331; percolation, 

 296, 297, 298, 299, 300, 303; 

 salt-treated, 302, 303, 307, 



[593] 



