588 



INDEX. 



Resin in guano, 305. 



Retentive power of soils for water, 

 70-73. 



Retrogression, nitrogen lost by, 142. 



Reverted phosphates, 389-391 ; deter- 

 mination of amount of, 391 ; for- 

 mation of, 387 ; value of, 391. 



Rhine, nitrates in waters of, 158. 



Rice-meal, an adulterant of guano, 

 319 ; manurial constituents of, 282. 



Rocks, phosphoric acid in, 202. 



Roots, influence of manures on com- 

 position of, 512 ; manuring of, 510- 

 522 ; Norfolk experiments on, 513 ; 

 potash removed in, 217. 



Rotation of crops, bearing of, on 

 nitrification, 195. 



Rotations, phosphoric acid in, 290 ; 

 potash removed in, 290. 



Rothamsted, alternate Avheat and 

 bean rotation at, 524 ; ammonia in 

 rain at, 49 ; barley experiments at, 

 566 ; Broadbalk Field, alteration in 

 composition of, 159 manuring of, 

 159 produce of wheat on, 159 ; 

 early experiments at, 33-36 ; ex- 

 periments, 560 - 572 ; experiments 

 with nitrate of soda at, 347 ; ex- 

 periments on nitrogen question at, 

 115 mangel - wurzel, 568 oats, 



567 potatoes at, 519 value of 

 nitrogen in farmyard manure, 271 ; 

 increase of nitrogen with manures 

 at, 137, 513 ; nitrates in barley- 

 soils of, 158 ; nitrates in cropped 

 soils of, 130, 157 ; nitrates in drain- 

 age of, 189 ; nitrates in wheat-soils 

 of, 131, 157 ; nitrogen as nitrates 

 in soils of, 129, 198 ; nitrogen, de- 

 crease of, in soils, 159 ; nitrogen in 

 pasture at, 126 ; pasture, increase 

 of nitrogen in, 158 ; retrogression 

 of nitrogen at, 142 ; soil, nature of, 

 561 nitrogen in, at various depths, 

 156 ; total amount of nitrogen lost 

 at, 142 ; turnip experiments at, 



568 ; unmanured fallow-land loses 

 nitrogen by drainage at, 141 ; wheat 

 experiments at, 500, 562-565. 



Roy on sources of plant-nitrogen, 42. 

 Rubidia in ash of plants, 55. 

 Ruffle, John, on superphosphate, 388. 

 Rye, manurial constituents in, 282. 

 Rye-grass suited for sewage, 435. 



Rye-straw, summer, composition of, 

 238 ; winter, composition of, 238. 



St Helena, experiments at, with 

 Peruvian guano, 301. 



Saldanha Bay guano, 328 ; nitrogen 

 in, 329 ; phosphoric acid in, 329. 



Salinas, 335. 



Salm - Horstmar, Prince, on water- 

 culture, 54. 



Salt, 465-473 ; action of, on crops, 

 472 ; adulterant of guano, 319 ; 

 amount applied, 473 ; antiquity of 

 use of, 465 ; an antiseptic, 468 ; 

 application of, 472 ; clarifies water, 

 470 ; coagulates clay, 470 ; decom- 

 poses minerals, 470 ; a germicide, 

 468 ; indirect action of, 468 ; me- 

 chanical action of, 470 ; nature of 

 action of, 465 ; not a necessary 

 plant -food, 466 ; occurrence of, 

 467 ; prevents rapid fermentation, 

 471 ; quantity to apply, 473 ; sol- 

 vent action of, 470 ; sources of, 468. 



Saltpetre, formation of, 164 ; occur- 

 rence of, 215 ; plantations, 163. 



Sand, absorptive power of, 68 ; an 

 adulterant of guano, 319 ; cal- 

 careous, absorptive power of, 98 ; 

 siliceous, absorptive power of, 98. 



Sandy soils deficient in lime, 451. 



Sandwich Islands, guano deposits at, 

 328. 



Saragossa Sea, sea-weed in, 339. 



Saussure, De, on absorption of gases 

 by soil, 81 ; on nitrogen in plants, 

 41 ; researches on plant-food by, 15. 



Sawdust an adulterant of guano, 319. 



Scheibler, Professor, on basic slag, 

 404. 



Schloesing and Muntz, on nitrifica- 

 tion, 51, 166 ; experiments on rate 

 of nitrification by, 185 ; on denitri- 

 fication, 179 ; on ferments effecting 

 nitrification, 167 ; on fixation of 

 free nitrogen, 42 ; on ammonia in 

 air, 119, 132 ; on nitrogen absorbed 

 by soil from air, 132 ; on tempera- 

 ture favourable for nitrification, 

 175. 



Schoenite, potash in, 220. 



Schlibler, on absorptive power of 

 soils, 98 ; on retentive power 'of 

 soils, 98. 



