296 INDEX. 



SEcnox 



Hornblende, ingredients of, . . . ^ .60 



" action of, air and moisture on, . . 77 



Horse-dung, analysis of, . . . . . . 203 



" *' value compared with cow-dung, . , 204 



" " fermentation of, . . . . . 204 



" " how to be treated, . . • (P- 144) 



'' boiling establishments, . . . . .210 



Hruschauer, analysis of vine ashes, . . . 21 



Human excrement, Fleitmann's analysis of, . . (p. 150) 



•' '• Berzelius's '•' . . (p. 149) 



Humic acid, . . . . . (p. 98) 



Humin, . . . . . . . 102 



Humus, ...... (p. 95) 



" constituents of, . . . . (p. 94) 



" formation of, . . ' . . (p. 94) 



Humin, formula of, . . . . . (p. 94) 



Humic acid, " formation of apocrenates by, . . 126 



Humate of ammonia, . . . • (P- 9''>) 



Hydrogen, . . . . . . .40 



" in sandy soil, . . . . . 127 



" considered as unity, . . . .55 



" combination of, . . . . . 55 



" excess of, in decaying soil, . . , 100 



" group, in organic bodies, . , . . 101 



I. 



Indian corn, northern limit of . . . . .26 



" '' temperature of germination, ... 26 



Iowa soils, analysis of, . . . . . (p. 33) 



Iodine, in land plants, ..... 87 



Irrigation, .... 254, 279, 281, 282, 283 



" most fertile source of benefit from, . . 283 



natural, ...... 286 



Iron, carburet of, . . . . . .65 



" geateof, ...... 122 



*' phosphate of, . . . . . .80 



" silicate of, ..... . 48 



" sulphate of, formation, . , . . ,79 



*' *' action, . . . , . 82 



