for food consumed, 232;
nitrogen in, 230;
phosphoric acid in, 230;
water in, 230.

Cows, percentage of food voided in excrements of, 281;
solid excrements of, 280;
urine voided by, 280.

Cress, experiments with, 41.

Crimea, bones from, 360.

Cropped soils, nitrates in, 157
--lost by drainage in, 141.

Crops, capacity of, for assimilating manures, 486;
difference in root-systems of, 488;
manuring of common farm, 493-530;
period of growth of, 489;
potash removed in, 218;
suited for sewage, 434;
variation in composition of, 490.

Crusius on phosphoric acid removed from the farm, 207.

Crust guanos, 308, 379.

Crystalloids, 491.

Curacao phosphates, 308, 330, 379.

Darmstadt experiments with basic slag, 410-413.

Darwin on origin of nitrate-fields, 335.

Daubeny on mineral sources of phosphoric acid, 200.

Davy, Sir Humphry, lectures of, on agricultural chemistry, 17-19;
on heat and water absorbing and retaining properties of soils, 57;
on hygroscopic power of soils, 99.

Deherain, on nitrification, 52;
on nitrification in sulphate of ammonia, 191;
on rate of nitrification, 186.

Denitrification, 177;
conditions favourable for, 178;
effected by bacteria, 178.

Derby, Lord, introduction of Peruvian guano by, 301.

Detmer on humus in soil, 47.

Dew, action of, on guano, 300;
explanation of, 77;
most abundant in summer, 78.

Dicalcic phosphate, 387;
formula of, 398;
molecular composition of, 398;
percentage composition of, 398.

Digby, Sir Kenelm, on value of nitrates to plants, 45;
theory of, on plant-food, 6-8.

Diorite, phosphoric acid in, 202, 211.

Direct manures, 113.

Dissolved-bone compound, 372.

Dissolved bones, 368; composition of, 371.

Dissolved guano, 310.

Dolerite, phosphoric acid in, 202, 211.

Dolomite, phosphoric acid in, 202, 211.

Downton experiments on sewage-sludge, 439.

Drainage, average of thirteen years, 160;
nitrates in, 160;
nitrates lost by, 140;
phosphoric acid lost by, 206;
potash lost by, 217.

Drainings of manure-heaps, analysis of, 290.

Dried blood, 424;
composition of, 424;
manure for sugar-cane, 425;
potash in, 219;
rate of nitrification in, 192;
source of nitrogen, 152;
suited for horticulture, 425.

Dried flesh, 425;
nitrogen in, 425.

Dried leaves, as litter, 242;
composition