XII 



HOW CROPS FEED. 



Carbonic acid, solvent action of. . . .128 



Carbouic oxide 93 



Chabasite 115 



" action on saline com- 

 pounds 345 



" formed in Roman mason- 

 ry a51 



Chalk soils 192 



Charcoal, absorbs gases 1C5 



" defecating action of. 174 



Chili saltpeter 253 



Chlorite . 113 



Chrysolite 114 



Clay 132,134, 154 



" absorptive power 174 



" effect of, on urine 293 



Clay-Blate 119 



Coffee, condenses gases 168 



Color of soil .. . 190 



Conglomerates.. 121 



Crenates , 231 



Crenic acid 227, 229 



Decay 289 



Deliquescence 103 



Deserts 197 



Dew : . . 189, 195 



Diffusion of gases 100 



Diorite 120 



Doleri te 120 



Dolomite 115, 121 



Draining 185 



Drain water, composition of 312 



Drift 144 



Dye stuffs, fixing of 174 



Earth-closet 171 



Eremacausis 289 



Evaporation, produces cold 188 



" amount of, from soil. 197 



Exhalation 202, 206 



Exposure of soil 195 



Feldspar 108 



" growth of barley in 160 



Fermentation 290 



Fixtation of bases in the soil 339 



Frost, effects of, on rocks 124 



" " " on soils 184,185 



Fumic acid 258 



Gases, absorbed by the plant 103 



" " " porous bo.lies.. 167 



" " " soils 16.5, 166 



" diffusion of 100 



" osmose of ^.102 



Glaciers 12.i 



Glycine 29(1 



GlycocoU 296 



Gneiss 119 



Granite 118, 120 



Gravel 152 



" warmth of 195 



Guanin 296 



Gypsum 115 



" does not directly absorb 



water 163 



" fixes ammonia 344 



Hardpan 150 



neat, absorption and radiation of. . 



188, 193 



" developed in flowering 24 



" of soil 187 



Hippuricacid 395, 277 



Hornblende 112 



Hydration of minerals 127 



Hydraulic cement 122 



Hydrochloric acid gas ; 93 



Hydrogen, supply of, to plants 95 



" In decay 291 



Hydrous silicates, formation of 352 



Hygroscopic quality 164 



Humates 230 



Humicacid 226, 229 



Humin 230, 229 



Humus 136, 224, 276 



" absorbent power for water.. 162 

 " absorbs salts from solutions. 172 



" action on minerals 138 



" chemical nature of 138 



" does it feed the plant? 232 



" not essential to crops 238 



" value of 182 



Iodine in sea-water 322 



Isomorphism Ill 



Kreatin 196 



Kaolinite 113,132 



Latent heat 188 



Lawes' and Gilbert's wheat experi- 

 ment? .372 



Leucite 113 



Lime, effects of 184, 185 



Limestone 121, 123 



Loam 154 



Lysimeter 314 



Magnesite 115 



Marble .. 121 



Marl 155 



^larsh gas. 91, 99 



Mica...' 109 



