INDEX. 



PAGB 



Grandeau method of humus estimation 132 



Granite soils, potash and phosphoric acid in 50 



Granitic rocks, weathering of 47 



sand, formation in arid climates 2 



Grano-diorite soils, of Sierra Nevada 51 



Granular sediments, influence upon tilling qualities 102 



Grape-vine, alkali, tolerance of 475 



Grasses, cultivated, sensitive to alkali 471 



Greasewood, range, tolerance of alkali ; figure 542, 543 



Greenstones, soils from 51 



Ground water, depth most favorable to crops 228 



variation of surface of 228 



Gulf-stream .... 295 



Gypsum or selenite, formation from sea-water evaporation 42 



how recognized 42 



H. 



Halite 76 



Hardpans, causes, formation and cements of 185 



Hardpan, physical, analysis of 103 



plowsole . . , 241 



Hawaiian Islands, humid and arid sides of 297 



soils, analyses of 356 



Hay bacillus ; figure 149, 150 



Heat and cold, effects on rocks i 



of high and low intensity 304 



reflection and dispersion from soil surface 304 



relations to soils and plant growth 301 



trapping of suns 288 



Heaviest clay soils, physical analysis of 115 



Heaving-out of grain 119 



Hematite 44 



Herbaceous plants as soil indicators 517 



Hog-wallows 114 



Hornblende and pyroxene 33 



weathering of 33 



Horsetail rushes, secretion of silica by 31 



Humates and ulmates 133 



cementing effects of in 



Humid and arid climates, rock-weathering in 47 



Humid region, upland soils of ; table 37 2 > 374 



Humification in soils 20 



normal conditions of 129 



tests ; Snyder, tables 14 



Humin substances, formation of I2 3 



Humus, amidic constitution of T 2 5 



and coal, amountsof.from vegetable substance 128 



