INDEX. 



585 



source of, m soil, 133 ; in oxen 

 excrements, 280 ; in pasture-lands, 

 158 ; peat-soils richest in, 123 ; in 

 Peruvian guano, 302, 306, 307, 329 ; 

 in pig-dung, 226-227 ; position of, 

 in agriculture, 115-160; relative 

 manurial value of, 556; Rotham- 

 sted experiments on, 115 ; in 

 scutch, 427 ; in sewage, 431 ; in 

 sewage-sludge, 439 ; in sheep -dung, 

 226 - 228 ; in sheep excrements, 

 280 ; in sheep-urine, 230 ; in soil, 

 120 ; in soil, portion of, easily 

 nitrifiable, 187 ; in soils at various 

 depths, 156 ; in soot, 428 ; source 

 of, in plants, 15, 16, 40-52 ; sources 

 of soil, 131-137 ; in straw, 237, 243 ; 

 in subsoil, 121 ; in surface - soil, 

 121 ; in swine-urine, 230 ; in wool- 

 len rags, 427. 



Nitrogenous guano, 300-308, 329. 



Nitrogenous manures, application of, 

 478 ; benefit cereals, 494 ; hurtful 

 to leguminous crops, 523. 



Nitrogenous organic substances, in 

 Chincha guano, 305 ; in concretion- 

 ary nodules, 328. 



Nitros omon as, 167. 



Nitrous acid, converted into nitric 

 acid, 168 ; formed from ammonia, 

 167. 



Nobbe, on fixation of free nitrogen, 

 136 ; on potash in soil, 108. 



Nollner on origin of nitrate - fields, 

 339. 



Norfolk, coprolites from, 374 ; experi- 

 ments on barley, 497 on meadow- 

 land, 509 on turnips, 513. 



North America, guano from, 298, 328. 



Norwegian apatite, 375. 



Oak-tree, water transpired by, 71. 



Oat-straw, composition of, 238 ; man- 

 urial constituents in, 282. 



Oats, Arendt's experiments with, 503 ; 

 avenine in, 503 ; fertilising ingre- 

 dients removed from soil by, 485 ; 

 hardy crop, 502 ; manurial con- 

 stituents in, 282 ; manuring of, 

 501-504 ; nitrogen removed in crop 

 of, 148 ; require mixed nitrogenous 

 manures, 502 ; source of nitrogen, 

 153 ; Rothamsted experiments on 

 growth of, 567. 



Oficinas, 342. 



Ohlendorff, introduction of dissolved 

 guano by, 311. 



Oilcakes, imports of, 153 ; source of 

 nitrogen, 153. 



Oil-seeds, source of nitrogen, 153. 



Oligoclase felspars, 103, 214 ; com- 

 position of, 103 ; potash in, 220. 



Organic matter, in bones, 363 ; in 

 dung, 228, 260 ; in manures, 543 ; 

 not necessary for nitrifying organ- 

 ism, 169. 



Orthoclase felspars, 103, 214 ; com- 

 position of, 103 ; potash in, 220. 



Ox-dung, fertilising ingredients in, 

 for food consumed, 228. 



Ox-urine, fertilising ingredients in, 

 232. 



Oxalic acid in guano, action of, 330. 



Oxen, excrements of, 280 ; food aided 

 by, 280 ; solid excreta voided by, 

 280 ; urine voided by, 280. 



Oxidation, 79 ; products of, 79, 80. 



Oxygen, absorbed by plant-roots, 81 ; 

 absorbed by soil, 81 ; evolved by 

 plants, 11 ; necessary for fertility, 

 81 ; necessary for nitrification, 52, 

 173 ; percentage of, in plants, 39 ; 

 source of, in plants, 39. 



Pabellon de Pica, guano from, 298, 

 302, 327; nitrogen in, 330; phos- 

 phoric acid in, 330. 



Pacific Islands, guano from, 298. 



Pacific Ocean, sea-weed in, 339. 



Palagonite as potash manure, 213. 



Palm-kernel meal, manurial constit- 

 uents in, 282. 



Pasteur, on fermentation in urine, 

 255 ; on nitrification, 166. 



Pastures, accumulation of nitrogen in, 

 134 ; benefited by basic slag, 414 ; 

 deficient in lime, 451 ; effect of 

 manure on herbage of, 505 ; nitro- 

 gen in, 158 ; permanent, 138, 194 

 manuring of, 509 ; season influ- 

 ences, 507 ; soil influences, 507. 



Patagonian guano, 308, 327 ; nitrogen 

 in, 330 ; phosphoric acid in, 330. 



Patent phosphate meal, 405. 



Patillos, guano deposits at, 327. 



Patos Island, guano deposits at, 328 ; 

 phosphoric acid in, 330. 



Patterson on superphosphate, 399. 



