INDEX. 



385 



Nitrate of ammonia, formation of, 308 



Nitrate of soda, 318 



action of, on earthy phosphates, 



88 

 experiments on cereals with, by 



Bavarian Society, 318 

 Nitric acid in rain water, 274 

 Nitrogen classification of manures, 279 



esteemed chief agent in manures, 278 



indefinite idea of, in manures, 279 



assimilable and sparingly assimilable, 

 280 



amount of in soils, 289 



amount of, in different layers of soils 

 illustrated in Russian black soil and in 

 Caen soil, 294 



cause of the inactivity of the great 

 mass of, in soils, 302 



most abundant in the upper ten inches 

 of soils, 294 



in soils and farm-yard manure com- 

 pared as to effect, 298 



profit and lossof, in the Saxon experi- 

 ments, 276 



Nitrogen compounds, function of, in 



seeds, 58 



in annuals, 58 



in perennials, 60 



in soils bear no ratio to their pro- 

 ductive powers, 290 

 supposed different forms of, in soils 



as operative and inoperative, 291, 292 

 in soils not distinguished by action 



of alkalies, 295 

 in farm-yard manure only partly 



separable by distillation with alkalies, 



298 

 in manures and soils, different 



effects of, on what dependent, 299 

 Nitrogenous food, experiments on -the 



growth of plants without, 56 

 removed in crops is more than fully 



restored by rain, 277 

 restored to soils by fodder plants, 



310 

 Nitrogenous manures not always the 



most efficacious, 271 

 effects of, not proportional to the 



nitrogen present, 310 



first effect of, 312 



when required, 310 



Nutritive substances, closeness of in 



soils (figure), 190 



proper relative proportions of, 

 131 



maximum and minimum of, in 



soils, 207 



minimum of, regulate the crop, 207 



effect of the absorption of, in the 



upper layers of the soil, 152 



Oat, food of, derived from arable soil 

 (figure), 200 



and turnip compared, 53 



several stages of growth of, 49 

 Oberbobritzsch, unmanured field, prod- 

 uce from, 186 



17 



Oberschona, unmanured field, produce 

 from, 186 



Organic matter in manure does not ar- 

 rest exhaustion, 182 



incorporation of in soils improves 



their physical condition, 96 



Osmosis, laws of, 65 



Palms, starch in stems of, 335 



Peas and barley plant, growth of com- 

 pared, 154 



Perennial plant, mode of growth of, 29 



Peruvian guano, composition of, 245 



and ash constituents of seeds, dif- 

 ference of, 246 



effect of, due to the presence of 



oxalic acid, 247 



moistened with sulphuric acid made 



more quickly available, 248 



Phosphate of lime, diffusion of in soil, 88 



Phosphoric acid and nitrogen, proportion 

 between in oats and turnips, 52 



Pierre, analysis of soil by, 294 



Pincus, experiments on clover with gyp- 

 sum, 320 



Plants, annual, biennial, and perennial, 

 vital properties compared, 29 



annual, mode of growth of, 33 

 leafy, mode of growth of, 43 



biennial, mode of growth of, 34 



perennial, mode of growth of, 31, 41 



growth of, without nitrogenous food, 

 56 



growth of in turf, 112 



in solutions of their food, 109 



underground organs of, 28, 31 



rich in starch, sugar, and gum, con- 

 tain much potash in their ash, 39 



store up food in certain organs for fu- 

 ture use, 41 



Pools, analysis of stagnant water of, 103 

 Potash in soils, not always available, 238 



necessary for vegetation, 246 

 Potato, constituents of, 199 



draws its principal constituents from 

 the arable surface soil, 199 



effect of the cultivation of. on arable 

 soil, 215 



Poudrette, nature of, 258 



Practical men, 236 



their teaching and practice often 



opposed to each other, 314 



Protoplastem of wheat plants, propor- 

 tion between nitrogenous and non-ni- 

 trogenous substances hi, 54 



11 



Radication of plants, 26 



importance of a knowledge of, 



28 



Rape-cake, its composition, 267 

 more diffusible in soils than guano, 



268 

 its fertilising action illustrated In 



the Saxon experiments. 268 



