Chapter 9

Importance in agriculture 293 Influence on British farming 294 Influence of guano not wholly good 295 Value of guano as a manure 296 Origin and occurrence of guano 297 Variation in composition of different guanos 299 I. Nitrogenous guano-- (_a_) Peruvian guano 300 Different deposits of Peruvian guano 301 Appearance, colour, and nature of Peruvian guano 303 Composition of Peruvian guano 304 (_b_) Other nitrogenous manures: Angamos, Ichaboe 306 II. Phosphatic guanos-- Occurrence of phosphatic guanos 308 Inequality in composition of phosphatic guanos 309 "Dissolved" phosphatic guano 310 "Equalised" or "rectified" guano 311 The action of phosphatic guanos as manures 312 Proportion of fertilising constituents in guano 314 Mode of application of guanos 315 Quantity of guano to be used 317 Adulteration of guano 318 So-called guanos-- Fish-guano 320 Value of fish-guano 322 Meat-meal guano 324 Value of meat-meal guano 324 Bat guano 325 Pigeon and fowl dung 325

APPENDIX TO CHAPTER VIII. NOTE I. Peruvian guano imported into United Kingdom, 1865-1893 327 II. Guano deposits of the world 327 III. Composition of concretionary nodules 328 IV. Table showing gradual deterioration of Peruvian guano, 1867-1881 329 V. Composition of different guanos 329 VI. Liebig's theory as to the action of oxalic acid in guano 330 VII. Analyses of dung of fowls, pigeons, ducks, and geese 331