580 



INDEX. 



285 ; decomposes double silicates, 

 463 ; favourable to clover, 464 ; 

 as an oxidising agent, 464. 



Hales, Stephen, theory of, on plant- 

 growth, 8. 



Hampe, Dr, on nitrogen in plants, 46. 



Harting on sources of plant-nitrogen, 

 42. 



Heat, of soils, 76-78 ; of fermenta- 

 tion, 78. 



Heiden, Dr, on application of farm- 

 yard manure, 265 ; on fixation of 

 bases and acids by soil, 59 ; ou loss of 

 ammonia from dung, 249 ; on per- 

 centage of food voided by animals, 

 253 ; on straw as litter, 244, 249. 



Hellriegel, on amount of water in 

 soils, 75 ; on barley, 498 ; on ni- 

 trogen in plants, 44. 



Helmout, Van, theory of, on source 

 of plant-food, 4. 



Henslow, Professor, on coprolites, 

 374. 



Heraus on organisms in soil, 95. 



Herbage, effect of manure on, 505. 



Herrings as manure, 321. 



Herve-Mangon, experiments on action 

 of light on plants by, 38. 



Hilgeustock on tetracalcic phosphate, 

 405. 



Hippuric acid, experiments with, 46 ; 

 in farmyard manure, 257. 



Hire, De la, on evolution of gases by 

 plants, 11. 



Hofmeister on horse excrements, 

 243. 



Hoof-guano, source of nitrogen, 152. 



Hoofs and horns, manure from, 425. 



Hops, manuring of, 528 ; potash re- 

 moved by, 217 ; slow-acting man- 

 ures benefit, 528. 



Horn, capable of nitrification, 182 ; 

 as manure, 425 ; nitrogen in, 426 ; 

 phosphoric acid in, 426. 



Hornblende, 105. 



Horse-dung, alkalies in, 226 ; com- 

 position of, in dry state, 227 ; hot, 

 225 ; nitrogen in, 225, 226 ; phos- 

 phoric acid in, 226 ; water in, 225, 

 226. 



Horse-manure, 242 ; amount produced 

 per day, 243 ; amount produced per 

 year, 243 ; analyses of. 283 ; dry 



matter in, 243 ; dry nature of, 245 ; 

 fermentation rapid in, 245 ; mineral 

 matter in, 243; nitrogen in, 243, 



Horse-urine, alkalies in, 230 ; com- 

 position of, in dry state, 231 ; fer- 

 tilising ingredients in, 232 ; nitrogen 

 in, 230 ; phosphoric acid in, 230 ; 

 water in, 230. 



Hosaus on assimilation of ammonia, 

 50. 



Howland Island guano, 309, 328 ; 

 phosphoric acid in, 330. 



Huanillos, guano from, 302, 327 ; 

 nitrogen in, 330 ; phosphoric acid 

 in, 330. 



Huano, 297. 



Hueppe on organisms in soil, 95. 



Hughes, John, on bracken-fern as 

 litter, 241 ; on composition of 

 bracken, 283. 



Humates in farmyard manure, 259. 



Humboldt, A., discovery of Peruvian 

 guano by, 300. 



Humic acid in farmyard manure, 

 258 ; in humus, 47. 



Humin in humus, 47. 



Humus, absorptive power of, 68, 98 ; 

 evaporation from, 99 ; nature of, in 

 soil, 47 ; soils improved by addi- 

 tion of, 273. 



Huou Island guano, 309, 328 ; phos- 

 phoric acid in, 330. 



Huxtable and Thompson on retention 

 of plant-food by soil, 57. 



Hydrated silicates, 107, 459. 



Hydrochloric acid as a fixer, 245. 



Hydrogen, amount of, in plants, 40 ; 

 source of, in plants, 40. 



Hygroscopic power of soils, 75. 



Ichaboe guano, 307 ; nitrogen in, 



329 ; phosphoric acid in, 329. 

 Independence Bay guano, 302, 327 ; 



nitrogen in, 329 ; phosphoric acid 



in, 329. 



India, nitre soils of, 162. 

 Indirect manures, 113, 114, 449-473. 

 Ingenhousz, John, experiments by, on 



nitrogen in plants, 41 ; on oxygen 



evolved by plants, 12. 

 Insoluble phosphate, 386; value of, 396. 

 Iodine, in ash of plants, 55 ; in 



nitrate of soda, 340, 342. 



