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

CHAPTER