Index 



435, chrysocolla, 436; in field 

 soils containing tailings, 437; 

 in plots containing Cu ap- 

 plied to CUSO4, 439; sensi- 

 tiveness to copper salts, 422. 

 Cottonseed meal, in culture ex- 

 periments, 142; ammonifica- 

 tion, 153-155. 

 Cultures. See Nutrient solution; 

 Pot cultures; Pure Cultures; 

 Sand; Water culture. 



Denitrification, causes, 48. 



Desert plains, soil columns, 247; 

 localities: Coachella Valley, 

 248, Imperial Valley, 247, Mo- 

 jave Mesa, 248, Owens River 

 Valley, 248. 



Diffusion," in soil colloids. 292,296, 

 301, 303, 309, 319, 321. 



Distribution, and Activities of 

 Bacteria in Soils of the Arid 

 Region, 1. 



Dried blood, in culture experi- 

 ments, 142-147; ammonifica- 

 tion, 41, 145, nitrification, 45- 

 47. 



Effect of Copper, Zinc, Iron and 

 Lead Salts on Ammonifica- 

 tion and Nitrification in Soils, 

 127. 



Effects of Calcium and Mag- 

 nesium Carbonates on Some 

 Biological Transformations of 

 Nitrogen in Soils, 39. 



Ether, stimulating powers on 

 plant organisms, 129. 



Experiments on the Effects of 

 Constituents of Solid Smelter 

 Wastes on Barley Growth in 

 Pot Cultures, 495. 



Ferrous sulfate, effect on: Am- 

 monification in soils, 130, 131, 

 nitrification in soils, 135, 546- 

 549, barley growth. 503, 504, 

 517, 560', 573-575. plant 

 growth, bibliography with 

 comments, 541-543. 



Fertilizer salts, effect on wheat 

 kernels. 121; relation to de- 

 flocculation, 336. 



Fish guano. See Guano. 



Flower production of tobacco, in- 

 fluence of: Culture solution, 

 354, nitrogen, 355, phosphorus, 

 359, potassium, 360. 



Forbes, R. H., 395. 



Fundamental Interrelationships 

 Between Certain Soluble Salts 

 and Colloids, 291. 



Gericke, W. F., 495. 



Gila River mining and irrigation 

 district, Arizona, 396; maps, 

 398, 406; distribution of cop- 

 per compounds, 401, in vege- 

 tation, 410, 411, in Gila River 

 waters, 459, 473. 



Gliadin content of wheat. See 

 Wheat, gliadin content. 



Gluten content of Wheat. See 

 Wheat, gluten content. 



Guano, bat, in culture experi- 

 ments, 142, ammonification, 

 161, 162; fish, in culture ex- 

 periments, 142, 156, ammoni- 

 fication, 157, 158, 159. 



Hilgard, E. W., investigation of 

 soils of California, 1, 16, 176; 

 cited on: formation of hu- 

 mus, 174, 175, unhumified ma- 

 terial, 258, gypsum treatment 

 against black alkali, 276, de- 

 flocculation of clay colloids, 

 337. 



Holter, M. E., acknowledgment of 

 assistance, 181. 



Humic phosphoric acid in soils, 

 268. 



Humid soils, compared with arid 

 soils, 270. 



Humus and Humus Nitrogen in 

 California Soil Columns, 1 73 ; 

 method of examination, 177; 

 characteristics peculiar to 

 California soils, 179; bacterial 

 activity, 179; distribution, 

 180; regions studied: Coast 

 Range valleys, 209, desert 

 plains, 247, northeastern lava- 

 bed region, 241, Sacramento 

 Valley. 181, San Joaquin Val- 

 ley, 191, Sierra Nevada foot- 

 hills, 208, Southern Califor- 

 nia. 225. 



Hydroxide ions, relation to diffu- 

 sion in soil colloids, 301, 325. 



Hygroscopic coefficient, doubtful 

 validity in determination of 

 quantity of colloidal matter, 

 304, 305. 



Influence of the Composition and 

 Concentration of the Nutrient 

 Solution on Plants Grown in 

 Sand Cultures, 341. 



Ton, acid, 329; hydroxide, 301, 325. 



Iron, effects on ammonifying and 

 nitrifying flora in soils. 127. 



Iron sulfate. See Ferrous sulfate. 



Irrigation, experiments with cop- 

 per solutions, 428; sediments, 

 397, 473. 



[591] 



