INDEX. 



Clover, requires nearly the same consti- 

 tuents as the potato, 207 



— and turnips, eflfect of in opening 

 the soil, 90 



— sick field, 137 



explanation of by Lawes and 



Gilbert, 162 



Compensation, law of, 242 



Compost, 145 



Compound manures, action of, not de- 

 pendent upon one constituent alouo, 

 263 



Copper in ash of plants, 58 



Com, conditions for formation of, 199 



Corn and straw, constituents in soils, 

 200 



relative proportions of in 



cereals affected by the weather, 192 



in the Saxon ex- 

 periments, 198, 203 



Crops reaped afford no indication of 

 quantity of nutritive mutter in the 

 ground, 194 



Cunnersdorf, manure experiments, 190 



— produce of unmanured fields of, 190 



— nearness of food in soil of, 197, 204 



— produce with farm-yard manure, 208 



— increased produce by farm-yard 

 manure, 209 



— soil, depth to which maniire pene- 

 trates, 224 



— produce with guano compared with 

 farm-yard manure, 267 



— produce with bone-earth and com- 

 parison with guano, 279 



— produce with rape cake, 283 



— experiments, effect of the nitrogen 

 in, 285 



DECREASING crops, progress of, 

 169 

 Diffusion, law of, does not explain the 

 absoqjtion of food by roots of plants, 

 53 



— experiments, 56 



Disinfection of excrements does not 



affect their energj', 274 

 Distribution of food by chemical and 



mechanical means, 87 

 Drainage, effect of, 90, 95 



— removal of siliceous plants by, 81, 



— water, its composition, 91 

 anaysis of, 363 



does not dissolve the food of 



plants, 95, 96, 102 

 Duckweed, power of selection in roots 



of, 51 

 Dung, mechanical action of, 146 



FAR 



EARTHY phosphates, 276 

 effect of, less marked in first 



year, 278 



— — diffusion of, through the soil, how 

 effected, 75, 77, 137 



— • — require the presence of potash 

 and silicic acid in the soil, 278 



and guano, comparative experi- 

 ments with, 279 



Eiu-opean husbandry, present Bt&tQ of, 

 237 



decline of, produced by the sys- 

 tem of farm-yard manuring, 252 



illustrated by Hessian 



Rhine district, 253 



Excrement, contain ash of food, 184 



— of man, 272 



collection of, in Rastadt, 273 



value of, 273 



not injured by disinfecting 



with sulphate of iron, 274 

 Exhaustion of soils, its nature, 74, 76, 



212 

 known by the average crop, 



252 

 in chemical and agricultural 



sense, 166 



law of, 167 



retarded by growth of fodder 



plants, 175 



— of wheat, oat, and rye soils, 172, 

 177 



FiU^LOW, 74 

 False teachers in agriculture, 239, 

 247 



Farm -yard manure, 144 



— effect of, varies with the 



composition of the soil, 212 



depends on the mi- 

 nimum nutritive matters in the soil, 

 213 



its mechanical action, 214 



restores fertility only by sup- 

 plying one or more deficient ingre- 

 dients of the soil, 213, 229 



law regulating the quantity 



to be applied, 218 



produce from, 208 



— — in the Saxon experi- 

 ments not always equal to the quan- 

 tity .applied, 209 



why generally useful, 214 



Saxon experiments with, 208, 



218 



— — manuring system, 188, 226, 

 236 



