The Project Gutenberg eBook of Manures and sthe Principles Of Manuring, by C. M. Aikman.

		Series 2.				Series 3.

	STANDARD MANURES	Standard manures,				Standard manures,
		and cross-dressed with—				and cross-dressed with—
		550 lb. nitrate of soda.				400 lb. amonium salts.
Plots.
		Roots.		Leaves.		Roots.		Leaves.
		Tons.	cwt.	Tons.	cwt.	Tons.	cwt.	Tons.	cwt.
1	Farmyard manure, 14 tons	22	11	4	2	22	3	5	7
2	Farmyard manure, 14 tons, and 3-1/2 cwt. superphosphate	23	12	4	14	21	8	5	6
3	Without manure, 1846, and since	13	7	3	4	6	14	2	18
4	3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 400 lb. mixed mineral manure	12	17	3	15	16	2	3	0
5	3-1/2 cwt. superphosphate	15	13	3	5	8	10	3	1
6	3-1/2 cwt. superphosphate, and 500 lb. sulphate of potash	15	15	2	18	14	6	2	16
7	3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 36-1/2 lb. ammonium salts	16	0	3	1	16	3	3	0

		Series 4.				Series 5.

	STANDARD MANURES	Standard manures,				Standard manures,
		and cross-dressed with				and cross-dressed with
		2000 lb. rape-cake, and				2000 lb. rape-cake.
Plots.		400 lb. ammonium salts.
		Roots.		Leaves.		Roots.		Leaves.
		Tons.	cwt.	Tons.	cwt.	Tons.	cwt.	Tons.	cwt.
1	Farmyard manure, 14 tons	24	11	6	1	23	7	4	6
2	Farmyard manure, 14 tons, and 3-1/2 cwt. superphosphate	23	12	6	1	23	1	4	6
3	Without manure, 1846, and since	10	11	3	17	11	2	3	0
4	3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 400 lb. mixed mineral manure	24	18	5	7	20	4	3	9
5	3-1/2 cwt. superphosphate	11	7	4	2	12	3	3	2
6	3-1/2 cwt. superphosphate, and 500 lb. sulphate of potash	21	6	5	7	16	14	2	15
7	3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 36-1/2 lb. ammonium salts	21	6	5	9	17	10	3	3

	Produce per Acre, weighed as Hay.
	Average per annum,			Average per annum,
Manures per Acre per Annum.	20 years, 1856-75			16 years, 1876-91
	(1st crops only).			(1st and 2d crops).
	10 years,	10 years,	20 years,	1st	2nd
	1856-65.	1866-75.	1856-75.	crops.	crops.	Total.
	cwt.	cwt.	cwt.	cwt.	cwt.	cwt.
Unmanured continuously	22-1/2	20	21-1/4	18	8-1/2	26-1/2
3-12 cwt. superphosphate of lime	23-14	21-1/4	22-1/4	18	9	27-1/2
3-1/2 cwt. superphosphate of lime, and 400 lb. ammonium salts	33-7/8	30-1/2	32-1/4	30-3/4	10-1/2	41-1/4
400 lb. ammonium salts	30-1/2	22	26-1/4	18-1/4	10-1/8	27-3/8
275 lb. nitrate of soda, 3-1/2 cwt. superphosphate, and mixed mineral manure	45-1/4	47-5/8	46-1/2	41-1/8	12-1/8	53-1/4
275 lb. nitrate of soda	34-1/4	33-1/2	33-7/8	30-1/8	10	40-1/8

		Produce per Acre—Tubers.
Plot.	Manures per Acre per Annum	Good.		Small.		Diseased.		Total.
		Tons.	cwt.	Tons.	cwt.	Tons.	cwt.	Tons.	cwt.
1	Unmanured	1	18	0	6-1/4	0	2-1/4	2	7-1/2
2	Farmyard manure (14 tons)	3	19-3/8	0	7-5/8	0	6-5/8	4	13-5/8
3	Farmyard manure (14 tons), and 3-1/2 cwt. superphosphate	4	9-1/2	0	8	0	8-3/4	5	6-1/4
4	Farmyard manure (14 tons), 3-1/2 cwt. superphosphate, and 550 lb. nitrate of soda	5	8	0	7	0	19-1/2	6	14-1/2
5	400 lb. ammonium salts	1	19-1/2	0	7-1/8	0	3-1/2	2	10-1/8
6	550 lb. nitrate of soda	2	11-7/8	0	6-7/8	0	5-1/4	3	4
7	400 lb. ammonium salts, 3-1/2 cwt. superphosphate, 300 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia	5	14-1/4	0	8-1/4	0	14-3/4	6	17-1/4
8	550 lb. nitrate of soda, 33-1/2 cwt. superphosphate, 300 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia	5	19-7/8	0	7-7/8	0	19-1/8	7	6-7/8
9	3-1/2 cwt. superphosphate	3	0-3/4	0	8	0	4-5/8	3	13-3/8
10	3-1/2 cwt. superphosphate, 300 lb. sulphate potash, 100 lb. sulphate soda, and 100 lb. sulphate magnesia	3	4-1/2	0	6-1/2	0	4-7/8	3	15-7/8
1. In each year the tops were spread on the respective plots.

		Produce per Acre—Tubers.
Plot.	Manures per Acre per Annum	Good.		Small.		Diseased.		Total.
		Tons.	cwt.	Tons.	cwt.	Tons.	cwt.	Tons.	cwt.
1	Unmanured in 1876, and each year since	1	3-3/4	0	3-3/4	0	0-1/4	1	7-3/4
2	Unmanured in 1882, and since; previously farmyard manure (14 tons)	2	14-1/4	0	4-3/4	0	2	3	1
3	Farmyard manure (14 tons) alone, 1883, and since; previously 3-1/2 cwt. superphosphate also	4	3-1/4	0	4-1/4	0	4-1/2	4	12
4	Farmyard manure (14 tons) alone, 1883, and since. In 1882 and previously 3-1/2 cwt. superphosphate, and in 1881 and previously 550 lb. nitrate of soda also	4	6-1/4	0	4-1/2	0	4-3/4	4	15-1/2
5	400 lb. ammonium salts	1	2-3/4	0	4-3/4	0	0-1/2	1	8
6	550 lb. nitrate of soda	1	17-3/4	0	3-3/4	0	0-3/4	2	2-1/4
7	400 lb. ammonium salts, 3-1/2 cwt. superphosphate, 300 lb. sulphate of potash, and 200 lb. mixed mineral manure	5	6-3/4	0	5	0	4-1/2	5	16-1/4
8	550 lb. nitrate of soda, 3-1/2 cwt. superphosphate, 300 lb. sulphate of potash, and 200 lb. mixed mineral manure	5	7-1/2	0	4-1/4	0	3-3/4	5	15-1/2
9	3-1/2 cwt. superphosphate	2	17-3/4	0	3-1/4	0	1	3	2
10	3-1/2 cwt. superphosphate, 300 lb. sulphate of potash, and 200 lb. mixed mineral manure	3	2-1/4	0	3-1/4	0	1-1/4	3	6-3/4

INDEX.

Abraum salts, 421.

Absorptive power of soils for water, 67, 98;

how to increase, 74.

Acidity in soils neutralised by lime, 458.

Acids fixed by soil, 58.

Adametz on organisms in soil, 92.

Adulteration of guano, 318-320.

Africa, guano from, 298, 328.

Agricultural chemistry, historical introduction to, 3-61;

Liebig's researches on, 23-32;
Liebig's services to, 31.

Agronomy, 56.

Air, ammonia in, 48, 118;

nitrates in, 118;
nitrogen in, 116;
organic nitrogen in, 118.

Aitken, Dr, experiments with basic slag, 413

—with beans, 526, 530;
on germ-life in bones, 368;
on manuring of turnips, 515.

Albert, Heinrich, on solubility of basic slag, 409.

Albite, composition of, 103.

Albuminates, 460.

Albuminoids, in plants, 491;

of milk, nitrification in, 182;
phosphorus in, 205.

Algerian phosphate, 379.

Algoa Bay, guano deposits at, 328.

Alkalies, in cow-dung, 226, 227

—cow-urine, 230
—horse-dung, 226, 227
—horse-urine, 230
—pig-dung, 226, 227
—pig-urine, 230
—sheep-dung, 226, 227
—sheep-urine, 230.

Alkalinity necessary for nitrification, 172.

Alumina, in ash of plants, 55;

compounds, reversion caused by, 388, 400;
salts, in salinas, 335.

America, virgin soils of, 133.

American farming, 86.

Amides, 501.

Ammonia, absorbed by soil, 81;

amount dissolved in rain, 49;
amount in air, 48;
amount in soil, 127;
amount supplied to soil by rain, 155;
converted into nitrates in soil, 50;
converted into nitrous acid, 167;
fixed by soil, 58;
from decomposition of farmyard manure, 258;
from gas-works, 353;
lost in mixing manures, 533;
relation of, to plants, 48-50;
salts, most easily nitrifiable, 191;
salts of, in farmyard manure, 257;
sulphate of, 352-358;
value of, as a manure, 352.

Ammonium chloride in Chincha guano, 305.

Ammonium-magnesium phosphate in Chincha guano, 305.

Ammonium oxalate in concretionary nodules, 328.

Ammonium phosphate, in Chincha guano, 305;

in concretionary nodules, 328.

Ammonium sulphate, 352-358;

in Chincha guano, 305;
in concretionary nodules, 328.

Ammonium sulphocyanate, 355.

Ammonium urate in concretionary nodules, 328.

Amphibole, potash in, 220.

Analysis, of manures, 539-554;

of soils, value of, 90.

Anderson, Dr, analyses of minerals by, 103, 105-107;

on nitrogen in soil, 121, 124.

Angamos, guano from, 301, 329.

Animals, phosphoric acid in, 205;

potash in, 205;
solid excreta of, 224;
urine of, 228.

Apatite, Canadian, 201, 374;

composition of, 210;
most abundant form of phosphoric acid, 200;
varieties of, 200.

Application of manures, 474-492.

Arabian coast, guano deposits on, 328.

Arable soil, absorptive power of, 98.

Arbrohlos Island guano, 309.

Arendt, experiments on oats by, 503.

Aristotelian doctrine of chemical elements, 4.

Artificial soil, 54.

Aruba phosphate, 308, 328, 379.

Ash, constituents of plants, 53-55;

of rye, phosphoric acid in, 204;
of wheat, phosphoric acid in, 204;
of farmyard manure, composition of, 287, 288.

Ashes, an adulterant of guano, 319;

mixed with manures, 532.

Asia, guano from, 298.

Asparagin, nitrification in, 182.

Atacama, nitrate of soda deposits at, 342.

Atmosphere, ammonia in, 48, 81;

relation of, to plants, 39.

Atwater on nitrogen in plants, 44.

Augite, 105.

Australia, guano from, 298;

virgin soils of, 133.

Avenine in oats, 503.

Aves guano, 309, 328;

phosphoric acid in, 330.

Bacilli, 94.

Bacon, Lord, on salt as a manure, 469.

Bacteria, in soil, 92;

different classes of, 93-96.

Baker Island guano, 309, 328;

phosphoric acid in, 330.

Ballestas, guano from, 302, 327;

nitrogen in, 329;
phosphoric acid in, 329.

Barilla, potash in, 420.

Barley, farmyard manure not suited for, 497;

fertilising ingredients removed from soil by, 485;
manurial constituents in, 282;
manuring of, 495, 498;
nitrogen removed in crop of, 145;
Norfolk experiments on, 497;
period of growth of, 495;
period of ripening of, 495;
Rothamsted experiments on growth of, 566;
soils suited for, 496;
uniform manuring of, 497.

Barley soils, amount of nitrates and nitrogen in, 158.

Barley-straw, composition of, 238;

manurial constituents in, 282.

Basalt, phosphoric acid in, 202, 210.

Bases fixed by soil, 58.

Basic ammonium phosphate in concretionary nodules, 328.

Basic process of steel-smelting, 400.

Basic silicates, 103.

Basic slag, 401-417;

after-effects of, 412;
application of, method of, 416
—rate of, 414;
compared with other manures, 410-414;
composition of, 404, 417;
Darmstadt experiments with, 410;
discovery of value of, 403;
manufacture of, 401;
preparation of, processes for, 406;
relative activity of, 411;
soils best suited for, 414;
solubility of, 408;
Wagner's experiments with, 408-413.

Bat guano, 320, 325;

nitrogen in, 325;
phosphoric acid in, 325.

Beans, fertilising ingredients removed from soil by, 485;

good effect of gypsum on, 526;
manurial constituents in, 282;
manuring of, 525-527;
phosphorus in, 205;
relative value of manurial ingredients to, 526;
source of nitrogen, 153.

Bean-straw, manurial constituents in, 282.

Beatson, General, experiments of, with Peruvian guano, 301.

Beddington meadows, irrigation at, 432.

Bedfordshire, coprolites from, 374.

Belgian phosphate, 377.

Berthelot on sources of plant-nitrogen, 42.

Biological properties of soil, 92-96.

Blood corpuscles, potash in, 217.

Blood, dried, 424;

composition of, 424;
manure for sugar-cane, 425;
potash in, 217, 219;
rate of nitrification in, 192;
source of nitrogen, 152;
suited for horticulture, 425.

Bohemia, phosphoric acid removed from, 206.

Bolivia, guano deposits at, 327.

Bollaert on nitrate deposits, 333.

Bone-ash, 369;

composition of, 372.

Bone-black, 369;

composition of, 372.

Bone-char, 369;

composition of, 372.

Bone-dust, 360.

Bone-meal, 361, 364;

composition of, 371;
condition of nitrogen in, 540.

Bone-phosphate, 385.

Bones, 359-372;

action of, 365;
boiled, 361;
bruised, 361;
capable of nitrification, 182;
collected in Britain, 353, 362;
composition of, 362, 371;
compound, 372;
crops suited for, 368;
dissolved, 368, 371;
early use of, 359;
fermentation of, 361;
floated, 365;
forms of, 360;
grinding of, 365;
imports of, 151;
inorganic matter in, 363;
nitrogen in, 151;
organic matter in, 363;
putrefaction of, 365, 366;
raw, 361;
source of nitrogen, 151;
treatment of, 364.

Bonnet, Charles, discovery of source of plant's carbon by, 11.

Boracic acid in salinas, 335.

Bordeaux phosphate, 379.

Boussingault, on dry matter in horse-manure, 243;

early researches of,
in agricultural chemistry, 21;
experiments by, on nitrification, 185, 198;
on excrements of pig, 250;
on nitrates in guano, 304;
on nitrogen in plants, 41, 42;
on nitrogen in soil, 124;
on nitrogen in excreta, 234;
on nitrogen lost during fermentation, 245.

Bracken-fern, analyses of, 283;

as litter, 241.

Bran, manurial constituents in, 282.

Bretschneider on sources of plant-nitrogen, 42.

Brewers' grain, manurial constituents in, 282.

Bromine in ash of plants, 55.

Browse Island guano, 309, 328;

phosphoric acid in, 330.

Brüstlein and Peters on fixation of bases and acids by soil, 59.

Buckland, Dr, discovery of coprolites by, 373.

Buckwheat absorbs ammonia, 352.

Bull River, phosphates from, 376.

Cabbages, benefited by saline manures, 529;

manuring of, 528-529;
soils suited for, 529.

Caird, Sir James, experiments by, with Peruvian guano, 301.

Calcareous earth, absorptive power of, 98;

stones, phosphoric acid in, 211.

Calcium phosphate in Chincha guano, 305.

Calcium sulphate in concretionary nodules, 328.

Caliche, composition of, 342;

occurrence of, 341.

California, guano deposits at, 328.

Cambridgeshire, coprolites from, 373.

Cameron, Sir Charles, on assimilation of urea by plants, 46.

Canadian apatite, 201, 374.

Cape Vert guano, phosphoric acid in, 330.

Carbolic acid, action of, on nitrifying organisms, 177.

Carbon, fixation of, by plants, 37;

in plants, discovery of source of, 11.

Carbon bisulphide, effect of, on nitrification, 166, 176.

Carbonate of ammonia formed in fermentation of dung, 247, 258.

Carbonic acid, absorbed by plants, 12

—by soil, 81;
in ash of plants, 55;
oxidation of, by bacteria, 95;
produced in decomposition of farmyard manure, 258.

Carbonising-works, ammonia from, 353, 358.

Carburetted hydrogen, produced in decomposition of farmyard manure, 258.

Caribbean phosphates, 379.

Carnallite, 420.

Carolina phosphate, 376.

Carrots, manurial constituents in, 282.

Catacombs, bones from, 360.

Catch-cropping, 138, 489.

Cattle foods, average composition of, 557.

Caustic lime, 453.

Cereals, manuring of, 493-504;

nitrogenous manures benefit, 494;
potash in, 217;
silicates absorbed by, 494;
value of nitrate of soda as manure for, 346.

Chalk, an adulterant of guano, 319;

lias, phosphoric acid in, 211.

Charcoal, a filter for sewage, 437.

Charleston phosphate, 376.

Chemical analysis of manures, interpretation of, 539;

value of, 539.

Chemical composition of soil, 87-92.

Cheshire, bones used in, 360.

Chesterfield Island guano, 309.

Chili and Peru, chief source of nitrate of soda, 162.

Chincha Island guano, 302, 303, 327;

composition of, 305;
nitrogen in, 329;
phosphoric acid in, 329.

Chipana, guano deposits at, 327.

Chlorapatite, composition of, 210.

Chlorine in ash of plants, 55.

Chloroform prevents nitrification, 166, 176.

Chlorophyll, organisms destitute of, 169;

produced by nitrate of soda, 347;
relation of, to fixation of carbon by plants, 37.

Chuca, 341.

Citrate of ammonia, solubility of phosphates in, 408.

Clay, absorptive power of, 68;

analysis of, 107;
grey, evaporation of water from, 99;
loamy, evaporation of water from, 99;
sandy, absorptive power of, 98
—evaporation of water from, 99;
soils, benefited by basic slag, 414
—puddling in, 455;
stiffish, evaporation of water from, 99;
strong absorptive power of, 98.

Clover-hay, fertilising ingredients removed from soil by, 486;

manurial constituents in, 282;
manuring of, 522.

Clover-sickness, 522.

Coal, nitrogen in, 353.

Coke-works, ammonia from, 353, 358.

Colloids, 491.

Colour of soil, 80;

difference in temperature due to, 80.

Columbia, guano deposits at, 327.

Composts, 113, 445-448;

farmyard manure a typical, 446;
manufacture of, 445;
object of, 445;
purposes served by, 445;
substances used for, 447.

Compound bones, 372.

Concretionary nodules, composition of, 328.

Conglomerate, 341.

Connecticut, experimental station at, 33.

Cooke, F. J., on, farmyard manure, 272, 277;

field experiments. 547;
manuring of barley, 497
—of mangels, 514
—of meadow-land, 509
—of swedes, 514
—of wheat, 501.

Copper, oxide of, in plants, 55.

Copperas, as a fixer, 246, 247.

Coprolites, 373;

percentage of phosphates in, 201:
occurrence of, 201, 373.

Corcovado guano, nitrogen in, 329;

phosphoric acid in, 329.

Cordilleras, 340, 341.

Costra, 341.

Cotton-cake, decorticated, manurial constituents in, 282.

Cotton-cake, undecorticated, manurial constituents in, 282.

Cotton-seeds, imports of, 153.

Cova, 341.

Covered manure, potatoes grown with, 289;

wheat grown with, 289.

Cow-dung, alkalies in, 226;

composition of, in dry state, 227;
cool, 225;
nitrogen in, 226;
phosphoric acid in, 226;
water in, 226.

Cow-manure, 247;

amount voided per day, 248;
amount voided per year, 248;
analysis of, 286;
dry matter in, 248;
fermentation in, slow, 248;
mineral matter in, 248;
mucilaginous matter in, 248;
nitrogen in, 248;
resinous matter in, 248.

Cow-urine, alkalies in, 230;

composition of, in dry state, 231;
fertilising ingredients in, 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.

Curaçao 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.

Dehérain, 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 of, 242;
nitrogen in, 242;
phosphoric acid in, 242;
potash in, 242.

Ducks' dung, analysis of, 331.

Duhamel and Hales, theory of, on plant-growth, 8.

Dundonald, Earl, treatise by, on agricultural chemistry, 13.

Dung and urine, composition of, 234.

Dutrochet on absorption of plant-food, 55.

Dyer, Dr Bernard, analyses of stable manure by, 283;

experiments on peat as litter, 240;
on nitrate of soda as manure for mangolds, 349.

Earth, an adulterant of guano, 319;

composition of solid crust of, 102.

Ecuador, guano deposits at, 327.

Egyptian guano, nitrogen in, 329;

phosphoric acid in, 329.

Elbe, waters of, phosphoric acid in, 206;

potash in, 217.

Elm-tree, water transpired by, 71.

Enderbury Island guano, 309, 328;

phosphoric acid in, 328.

Endosmosis, 55.

English farming, 86.

Equalised guano, 311.

Essex, coprolites from, 374.

Estremadura phosphate, 375.

Ethylamine, nitrification in, 182.

Evaporation from soil, 71, 72, 98.

Excreta, amount of nitrogen in, 149, 292;

composition of, 226, 292;
difference in amount of, for food consumed, 279;
liquid, in farmyard manure, 224;
solid, in farmyard manure, 224;
solid, undigested food in, 224;
solid, voided by cows, 280, 292;
solid, voided by horse, 292;
solid, voided by oxen, 280;
solid, voided by sheep, 280, 292.

Factors for calculating manurial ingredients

into their different compounds, 553.

Falkland guano, 308;

nitrogen in, 330;
phosphoric acid in, 330.

Fallow-fields, nitrates formed in, 188.

Fanning Island guano, 328;

phosphoric acid in, 330.

Farmyard manure, 223-292;

action of, on soils, 273;
ammonia in, 258;
amount produced on farm per year, 252;
analyses of, 259, 286;
application of, 264;
ash of, 287, 288;
carbonic acid gas in, 258;
classes of constituents of, 224;
compared with artificials, 476;
composition of, 259;
denitrification in, 179;
depth to plough to, 267;
effect of, on potatoes, 520;
fertilising matter in, 270;
fire-fang in, 264;
fresh, composition of, 286, 288;
functions of, 268;
heat in fermentation of, 78, 253;
humates in, 259;
humic acid in, 258;
inadequate source of nitrogen to soil, 271;
indirect influence of, 273;
influence of, on soil, 475;
Lawes, Sir John, on composition of, 291;
Lord Kinnaird's experiments with, 289;
marsh-gas in, 258;
mineral matter in, 260;
moisture in, 260;
nitric acid in, 259;
nitrogen in, 260;
ratio of, to ash ingredients, 271;
organic matter in, 260;
phosphoretted hydrogen in, 258;
phosphoric acid in, 260;
potash in, 260;
products of decomposition of, 257;
rate of application of, 275;
retrogression of nitrogen in, 142;
rotten, composition of, 287, 288
—value of, 261;
rotting, effects of, on, 262;
solid excreta in, 224;
sulphuretted hydrogen in, 258;
supplemented with nitrogen, 271;
supplemented with phosphoric acid, 272;
temperature, effect of, on soil, 79, 274;
typical compost, 446;
ulmates in, 259;
ulmic acid in, 258;
unfavourable to certain crops, 477;
urine in, 228;
value of, 268;
variation in composition of, 223;
water in, 258.

Fatty acids in guano, 305.

Felspars, 103;

albite, 103;
composition of, 103;
labradorite, 220;
oligoclase, 103, 214, 220;
orthoclase, 103, 214, 220;
phosphoric acid in, 211;
potash manures, 213;
potash in, percentage of, 213, 220.

Ferment, aerobic, 173, 255;

anaerobic, 255.

Fermentation, ammonium carbonate formed during, 245;

in bones, 365;
heat of, 79;
of farmyard manure, 253;
of guano, 299;
temperature of, 256.

Fern, bracken, as litter, 241.

Ferric chloride, test for sulphocyanates, 355.

Fertilisers and Feeding Stuffs Act, 543.

Fertilising ingredients, amount of soluble, in soil, 90;

amounts removed by different crops, 484, 485;
chemical condition of, in soil, 89;
lodge in seed, 491;
in soil, 87.

Fertility, of the soil, 65-97;

potential, of soil, 214, 549;
properties necessary for, 66;
supply of oxygen necessary for, 81.

Field experiments, 545, 548;

educational value of, 547;
on rate of nitrification, 187.

Finger-and-toe prevented by lime, 461.

Fire-fang in farmyard manure, 264.

Fischer on absorption of plant-food, 55.

Fish-guano, 320-323;

application of, 323;
consumption of, 152;
manufacture of, 321;
nitrogen in, 321;
phosphoric acid in, 321;
production of, 322;
source of nitrogen, 152;
value of, 322.

Fixers, 246;

chemical reactions with, 284.

Fleece, potash in, 217.

Fleischer, Professor, on solubility of phosphates, 408.

Flesh-guano, 320.

Flint Island guano, 309.

Flitcham experiments on growth of wheat, 500.

Floated bones, 362, 365.

Florida phosphate, 378.

Fluorapatite, composition of, 210.

Food, consumed by pigs, 281;

dry matter of, voided in dung, 228;
percentage of, in excrements, 281.

Food-constituents, plant, necessary for nitrification, 170.

Forbes, David, on nitrate-fields of Chili, 334.

Forest-soils, absence of nitrification in, 193.

Fowl-dung, 320, 326;

analysis of, 331.

Fownes on phosphoric acid in rocks, 202.

Frankland, P. F., experiments on nitrification, 52, 167, 198.

Franklin, Benjamin, experiment of, with gypsum, 462.

Frey Bentos, meat-meal guano from, 324.

Galapagos Islands, guano deposits at, 327.

Garden earth, absorptive power of, 98;

ammonia in, 128.

Gas-liquor, ammonia in, 353.

Gas-works, ammonia from, 353, 358.

Gases, absorbed by soils, 81;

present in soil, 100.

Gazzeri on retention by soil of plant-food, 57.

Geese-dung, analysis of, 331.

Geic acid in humus, 47.

Gelatin, nitrification in, 182;

from bones, 364.

Germany, agricultural research in, 32;

bones imported from, 360;
manufacture of meat-meal guano in, 324.

Germination, influence of temperature on, 76;

oxygen necessary for, 81.

Gilbert, Sir J. Henry, on barley-manuring, 496;

on Liebig's mineral theory, 28;
on manuring of potatoes, 520;
Presidential address of, 61;
and see Lawes and Gilbert.

Glauber on artificial production of nitre, 164.

Glue, 364.

Glycin, assimilated by plants, 47.

Glycocoll, experiments with, 46.

Gneiss, 106;

phosphoric acid in, 207.

Grandeau, Professor, on forms of plant-food in soil, 107;

on loss of phosphoric acid, 207.

Granite, 105;

in guano, 303;
phosphoric acid in, 202, 211;
potash in, 214.

Grass, Bangor experiments on, 508;

effect of manure on, 505;
influence of farmyard manure on, 506;
manuring of, 504-510.

Gray, Asa, on transpiration by plants, 71.

Great Cayman guano, 379.

Green manures, 113.

Grouven on guano, 313.

Guanape Island guano, 302, 327;

nitrogen in, 329;
phosphoric acid in, 329.

Guanine, 304;

experiments with, 46.

Guano, 293-331;

action of, as a manure, 312;
adulteration of, 318;
application of, 315;
bat, 325;
composition of, 305, 329;
crust, 308;
deposits of the world, 327;
dissolved, 310;
equalised, 309;
fermentation of, 299;
fertilising constituents in, 314;
fish, 320-323;
importance of, in agriculture, 293;
inequality in composition of, 309;
influence of, on farming, 294;
meat-meal, 324;
mode of application of, 315;
nitrification in, rate of, 192;
nitrogenous, 300-308;
origin of, 297;
Peruvian, 300-306;
phosphatic, 308;
quantity to apply, 317;
rectified, 311;
so-called, 320;
source of phosphoric acid, 202;
source of potash, 219;
value of, as a manure, 296;
variation in composition of, 299.

Gulf of Mexico, guano deposits at, 328.

Gulls, guano from, 297.

Gunning on sources of plant-nitrogen, 42.

Gunpowder, exports of, 149;

nitrogen lost in, 149;
production, annual, of, 149;
saltpetre in, 149, 333.

Gypsum, 462-464;

absorptive power of, 98;
action of, mode of, 462—on nitrification, 173;
an adulterant of guano, 319;
as a fixer, 246, 247, 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 fermentation, 78.

Heiden, Dr, on application of farmyard manure, 265;

on fixation of bases and acids by soil, 59;
on loss of ammonia from dung, 249;
on percentage of food voided by animals, 253;
on straw as litter, 244, 249.

Hellriegel, on amount of water in soils, 75;

on barley, 498;
on nitrogen in plants, 44.

Helmont, Van, theory of, on source of plant-food, 4.

Henslow, Professor, on coprolites, 374.

Heraüs on organisms in soil, 95.

Herbage, effect of manure on, 505.

Herrings as manure, 321.

Hervé-Mangon, experiments on action of light on plants by, 38.

Hilgenstock 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 removed by, 217;
slow-acting manures benefit, 528.

Horn, capable of nitrification, 182;

as manure, 425;
nitrogen in, 426;
phosphoric acid in, 426.

Hornblende, 105.

Horse-dung, alkalies in, 226;

composition of, in dry state, 227;
hot, 225;
nitrogen in, 225, 226;
phosphoric 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, 244.

Horse-urine, alkalies in, 230;

composition of, in dry state, 231;
fertilising ingredients in, 232;
nitrogen in, 230;
phosphoric acid in, 230;
water in, 230.

Hosäus 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 addition of, 273.

Huon Island guano, 309, 328;

phosphoric 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.

Iquique, nitrate of soda from, 333.

Iron in ash of plants, 54;

necessary for plant-growth, 55;
reversion in superphosphates caused by, 390, 399.

Iron-works, ammonia from, 353, 355, 358.

Irrigation, 431-433;

intermittent, 434;
subsoil, 432.

Jamieson, Professor, experiments with coprolites, 380.

Jarvis Island guano, 309, 328;

phosphoric acid in, 330.

Jersey, manuring of potatoes in, 521.

Johnson, Professor S. W., on application of superphosphate, 395;

on Earl Dundonald, 13;
on nitrogen in buffalo-horn shavings, 426;
on nitrogen in soils, 123;
on solubility of basic slag, 408;
value of organic nitrogen to plant, 46.

Jürgensen on nitrogen in excreta, 234.

Kainit, as a fixer, 247;

potash in, percentage of, 214, 220, 421;
rate of application of, 423.

Kaolin clay, analysis of, 104.

Karmrodt, analysis of Chincha Island guano, 305;

of concretionary nodules, 328.

Karnallite, potash in, 220.

Kellner, experiments on nitrification by, 52.

Kelp, potash in, 420.

Kieserite, 420.

Kinnaird, Lord, experiments by, with farmyard manure, 289.

Kitchen-garden soil, nitrogenous matter in, 122.

Knop on condition of nitrates in soil, 138.

Koosaw River, phosphates from, 376.

Kreatin assimilated by plants, 47.

Kuria Muria guano, 309, 328.

Labrador, guano deposits at, 328.

Labradorite, 214;

potash in, 220.

Lacepede Island guano, 309, 328;

phosphoric acid in, 330.

Lahn phosphate, 379.

Lava, phosphoric acid in, 202, 211.

Lawes, Sir J. B., and Gilbert, early researches of, at Rothamsted, 34;

experiments with farmyard manure, 271;
experiments with Peruvian guano, 301;
inauguration of Rothamsted experiments by, 33;
on composition of farmyard manure, 291;
on manuring of wheat, 483;
on motion of plant's sap, 56;
on percentage of food in excreta, 233;
on rate of nitrification, 186;
on sources of plant-nitrogen, 43;
on sulphate of ammonia, 356;
on unexhausted manures, 550, 557-559.

Lawes, Sir J. B., experiments with guano by, 301;

manufacture of superphosphate by, 382;
on application of superphosphate, 395;
on bones, 359;
on composition of farmyard manure, 291;
on farmyard manure, 477;
on loss of nitrates, 142;
on sources of nitrogen, 154.

Leather, as manure, 428;

nitrogen in, 428.

Leaves, dried, as litter, 242;

nitrogen in, 242;
phosphoric acid in, 242;
potash in, 242.

Legrange, Charles, on extent of nitrate-fields, 343.

Leguminous plants, benefited by basic slag, 414

—by potash, 523;
fixation of free nitrogen by, 42;
gain of nitrogen with, 135;
manuring of, 522-527, 530;
nitrogenous manures hurtful to, 523.

Lehmann on ammonia as plant-food, 50, 352.

Leipzig, bones from, 361.

Leones, guano deposits at, 327.

Leucite, potash in, 220.

Lias chalk, phosphoric acid in, 211.

Liebig, criticism of humus theory by, 25;

dissolved bones discovered by, 361;
first report to British Association, 24;
manufacture of superphosphate from bones by, 359;
mineral theory of, 26-29;
on ammonia as a manure, 352;
on importation of bones by Britain, 360;
researches of, in agricultural chemistry, 23-32;
services of, to agricultural chemistry, 31;
theory of manures by, 29;
theory of, on rotation of crops, 29.

Light, action of, on plant-growth, 38.

Lime, 449-461;

abundant occurrence of, 452;
action of, 461
—contradictory, 450
—not thoroughly understood, 449
—on nitrogenous organic matter, 460
—on soil's texture, 455;
antiquity of, as a manure, 449;
binding effect of, 457;
biological action of, 459;
caustic, 453;
chemical action of, 457;
decomposes minerals, 458;
different forms of, 453;
effect of, on soils, 112;
fixed by soils, 58;
in ash of plants, 54;
mechanical functions of, 455;
mild, 453;
necessary for nitrification, 171, 459
—for plant-growth, 55, 450;
neutralises acidity in soils, 458;
phosphates of, 385-388;
pig excrements contain, 281;
prevents clay puddling, 456;
returned to soil, 452;
soils contain, 450-452.

Limestone, analyses of, 106;

evaporation of water from, 99;
occurrence of, 452.

Linseed, imports of, 153;

manurial constituents of, 282.

Linseed-cake, manurial constituents of, 282.

Liquid manure, 442-444.

Lithia in ash of plants, 55.

Litter, loam as, 239;

peat as, 240;
straw as, 236;
uses of, 236.

Lloyd on fattening animals, 253.

Loam, as litter, 239;

evaporation of water from, 99;
poor in fertilising matter, 239.

Lobos, guano deposits at, 327.

Lobos de Afuera guano, 302, 327.

Macabi Island guano, 302, 327;

nitrogen in, 329;
phosphoric acid in, 329.

Maercker, Professor, on destruction of nitrifying organisms, 177.

Magnesia, fixed by soils, 58;

in ash of plants, 54;
in pig excrements, 281;
necessary for nitrification, 171;
necessary for plant-growth, 55;
sulphate of, as a fixer, 246, 285.

Maize, absorbs ammonia, 352;

fertilising ingredients removed from soil by, 485;
manurial constituents in, 282;
source of nitrogen, 153.

Malden Island guano, 309, 328;

phosphoric acid in, 330.

Malpighi on importance of atmospheric air for germination, 39.

Malt-dust, manurial constituents in, 282.

Manganese, oxide of, in ash of plants, 54.

Mangels, fertilising ingredients removed from soil by, 485;

guano a manure for, 318;
manurial constituents in, 282;
manuring of, 346, 511, 513, 514;
Rothamsted experiments on growth of, 568.

Manitoba soils, nitrogen in, at various depths, 156;

rate of nitrification in, 186.

Manure, cow, 247;

farmyard, 223-292;
horse, 243;
liquid, 442-444;
meaning of word, 109;
pig, 250;
sewage, 430-441;
sheep, 251;
stable, from peat-moss, 283
—wheat-straw, 283.

Manures, action of, 61;

analysis of, interpretation of, 539-544;
application of, 474-492;
method of, 531-538; cash prices of, 555;
equal distribution of, 531;
functions of, 109, increase soil-fertility, 474;
intrinsic value of, 545;
lasting effects of, 483;
methods of valuing, 544;
minor artificial, 424-429;
mixing of, 531-538;
nitrogenous, 293-359;
phosphatic, 359-417;
potassic, 418-423;
quantities of, applied to oats, 504;
unexhausted, 549-552, 558;
units for determining commercial value of, 554;
valuation of, 539-559;
value of, deduced from experiments, 548;
various classes of, 111-114.

Manurial constituents of various foods, 282.

Manurial ingredients, unit value of, 544.

Manuring of, barley, 495-498;

beans, 525-527, 530;
cabbages, 528;
cereals, 493-504;
clover, 524;
common farm crops, 493-530;
grass, 504-510;
hops, 528;
leguminous crops, 522-528;
mangels, 511, 513, 514;
oats, 493-504;
peas, 527;
potatoes, 517-522;
roots, 510-517;
turnips, 510, 511, 513-517;
wheat, 499-501.

Maracaïbo guano, nitrogen in, 330;

phosphoric acid in, 330.

Marl, phosphoric acid in, 211.

Marsh-gas from farmyard manure, 258.

Meadow-hay, fertilising ingredients removed from soil by, 485;

manurial constituents in, 282;
Rothamsted experiments on manuring of, 570.

Meadow-land, benefited by basic slag, 414, 508;

manuring of, 508;
Norfolk experiments on, 509.

Meat-meal guano, 320, 324;

composition of, 152;
imports of, 324;
manufacture of, 324;
nitrogen in, 324;
phosphoric acid in, 324;
rate of nitrification in, 192;
source of nitrogen, 152;
value of, 324.

Mechi on liquid manure, 442.

Mejillones guano, 309, 327;

phosphoric acid in, 330.

Mène, on sources of plant-nitrogen, 42.

Menhaddo, guano manufactured from, 322.

Mexico phosphate, 308, 328.

Mica, analysis of, 105;

potash in, 214, 220.

Micro-organisms, convert ammonia into nitrous acid, 167;

convert nitrous acid into nitric acid, 168;
effect fermentation, 80;
effect fixation of free nitrogen, 44;
effect nitrification, 161;
oxidising power of, 197.

Mild lime, 453.

Milk, nitrification in albuminoids of, 182;

nitrogen removed in, 147;
phosphoric acid removed in, 207;
potash removed in, 218.

Mineral phosphates, 373-381;

value of, as a manure, 380.

Mineral salts necessary for nitrification, 52.

Minor artificial manures, 424-429.

Mixing manures, 532-538;

ammonia lost in, 533;
nitric acid lost in, 536;
phosphates reverted in, 536.

Moisture, atmospheric, action on guano, 300;

in farmyard manure, 260;
in manures, 543;
necessary for nitrification, 52, 176.

Molds, 94.

Mona guano, 309.

Mond, Ludwig, on nitrogen in coal, 354.

Monks guano, 327;

phosphoric acid in, 330.

Monocalcic phosphate, 386;

formula of, 398;
molecular composition of, 398;
percentage composition of, 398;
reversion of, with iron and alumina compounds, 399
—with tricalcic phosphate, 399.

Mulder on humus in soil, 47, 126.

Müller, A., on nitrogen in soil, 121, 124.

Munro, Dr J. M. H., on nitrification, 52;

on sewage-sludge as manure, 439;
on urine voided, 292.

Müntz, on ammonia in air, 118;

on nitrifying organisms in soil, 180;
on oxidising power of micro-organisms, 197.

Muriate of potash, application of, 423;

forms calcium chloride, 422;
harmful effects of, 421;
more concentrated than sulphate, 422.

Mustard, 139.

Navassa phosphate, 308, 328, 379.

Nesbit on composition of guano, 301.

New Granada, guano deposits at, 327.

New Zealand, meat-meal guano from, 324.

Nile, nitrates in waters of, 159.

"Nitraries," 163.

Nitrate-fields, appearance of, 340;

origin of, 334.

Nitrate of soda, 332-351;

amount exported from Chili, 151, 332, 351;
amount imported into Britain, 151, 351;
appearance of fields of, 340;
application of, 347;
Chili and Peru chief source of, 161;
composition of, 343;
crops suited by, 346;
discovery of deposits of, 333;
extent of deposits of, 342;
encourages deep roots, 344;
formation of fields of, 334-340;
method of applying, 347;
method of mining, 341;
nitric acid in, source of, 337;
nitrogen in, percentage of, 343;
not an exhausting manure, 345;
origin of fields of, 334;
properties of, 343;
quantity to apply, 348;
shipments of, 351;
soils benefited by, 348;
source of nitrogen, 150;
top-dressing with, 344.

Nitrates, amount lost by drainage, 140;

amount produced at different times, 189;
amount in soil, 129;
conditions diminishing loss of, 139;
constantly formed in soil, 138;
in barley-soils, 158;
in cropped soils, 130, 157;
in drainage-waters, 160, 188;
in fallow-soils, 129;
in manured wheat-soils, 131, 157;
in soil, 129, 162;
lost by drainage, 137;
most formed in summer, 139;
nitrogen as, in Rothamsted soils, 198;
position of, in soil, 188;
quantity formed in fallow-fields, 188.

Nitre, beds, 163;

occurrence of, 162;
soils of India, 162.

Nitric acid, amount of, supplied to soil by rain, 155;

derived from sea weed, 337;
formed from ammonia, 118;
formed from nitrous acid, 168;
in farmyard manure, 259;
in soil, 128;
lost in mixing manures, 536;
most important nitrogen compound for plants, 161;
relation of, to plants, 50;
source of, in nitrate of soda, 337.

Nitrification, 51, 52, 161-198;

action of gypsum on, 173;
alkalinity necessary for, 172;
in asparagin, 182;
bearing of, on agriculture, 193;
in bones, 182;
cause of, 165;
conditions favourable for, 170;
denitrification, 177-179;
effected by micro-organisms, 51, 167;
in ethylamine, 182;
in fallow-fields, 184;
food-constituents necessary for, 170;
field experiments on rate of, 187;
in gelatin, 182;
in horn, 182;
laboratory experiments on rate of, 185;
in manures, 190, 192;
in milk albuminoids, 182;
mineral salts necessary for, 52;
moisture necessary for, 52, 176;
old theories on, 196;
organic matter not necessary for, 169, 196;
oxygen necessary for, 52, 173;
plant-roots promote, 181;
in rape-cake, 182;
rate of, 183;
rotation of crops, bearing of, on, 195;
soil best suited for, 192;
in subsoils, conditions favourable for, 181;
substances capable of, 181;
in summer, 183;
sunlight, effect of, on, 176;
temperature necessary for, 52, 175;
in thiocyanates, 182;
in urea, 182;
in wool, 182.

Nitrifying organisms, depth found at in soil, 180;

distribution of, in soil, 179;
effect of poisons on, 176;
organic matter not required by, 169.

Nitrobaeter, 167.

Nitrogen, 115-160;

absorbed by soil, 81, 131;
accumulates in pastures, 134;
in air, 116;
as ammonia in soils, 127;
amount of, in plants, 40;
amount of, in soil, 123;
artificial supply of, 150;
in bat guano, 325;
in bones, 363, 364;
combined, in air, 118;
combined, in rain, 119, 155;
condition of, in manures, 540;
converted into nitrates in soil, 51;
in cow-dung, 226-228;
in cow excrements, 278;
in cow-urine, 230;
difference between surface and subsoil, 126;
different forms of, 45, 116;
dissolved in rain, 131;
in dried blood, 424;
in farmyard manure, 260;
in fish-guano, 321;
fixation of free, 136;
forms of, in plants, 491;
free, relation of, to plant, 117;
gain of, with leguminous crops, 135;
in guanos, 329;
in hoofs and horns, 426;
in horse-dung, 226-228;
in horse-manure, 243;
in horse-urine, 230;
importance of, in soil, 88;
in lean flesh, 424;
in leather, 428;
least abundant of manurial ingredients in soil, 271;
loss of, artificial sources of, 144;
loss of, by crops, 144;
loss of, on farm, 146;
loss of, sources of, 137-150;
loss of, total amount of, 142;
lost in the arts, 148;
lost in free condition, 141;
lost in treating farmyard manure, 146;
lost in milk, 147;
lost by retrogression, 142;
in Manitoba soils, 156;
in meat-guano, 324;
nature of, in soil, 124;
as nitrates in soil, 128;
as nitrates in cropped soils, 130, 157;
as nitrates in Rothamsted soils, 198;
as nitrates in wheat-soils, 157;
in nitrate of soda, 343;
nitric, in soil, 128;
organic, absorbed by plants, 47;
organic, in soil, 125;
original source of, in soil, 133;
in oxen excrements, 280;
in pasture-lands, 158;
peat-soils richest in, 123;
in Peruvian guano, 302, 306, 307, 329;
in pig-dung, 226-227;
position of, in agriculture, 115-160;
relative manurial value of, 556;
Rothamsted experiments on, 115;
in scutch, 427;
in sewage, 431;
in sewage-sludge, 439;
in sheep-dung, 226-228;
in sheep excrements, 280;
in sheep-urine, 230;
in soil, 120;
in soil, portion of, easily nitrifiable, 187;
in soils at various depths, 156;
in soot, 428;
source of, in plants, 15, 16, 40-52;
sources of soil, 131-137;
in straw, 237, 243;
in subsoil, 121;
in surface-soil, 121;
in swine-urine, 230;
in woollen rags, 427.

Nitrogenous guano, 300-308, 329.

Nitrogenous manures, application of, 478;

benefit cereals, 494;
hurtful to leguminous crops, 523.

Nitrogenous organic substances, in Chincha guano, 305;

in concretionary nodules, 328.

Nitrosomonas, 167.

Nitrous acid, converted into nitric acid, 168;

formed from ammonia, 167.

Nobbe, on fixation of free nitrogen, 136;

on potash in soil, 108.

Nöllner on origin of nitrate-fields, 339.

Norfolk, coprolites from, 374;

experiments on barley, 497
—on meadow-land, 509
—on turnips, 513.

North America, guano from, 298, 328.

Norwegian apatite, 375.

Oak-tree, water transpired by, 71.

Oat-straw, composition of, 238;

manurial constituents in, 282.

Oats, Arendt's experiments with, 503;

avenine in, 503;
fertilising ingredients removed from soil by, 485;
hardy crop, 502;
manurial constituents in, 282;
manuring of, 501-504;
nitrogen removed in crop of, 148;
require mixed nitrogenous manures, 502;
source of nitrogen, 153;
Rothamsted experiments on growth of, 567.

Oficinas, 342.

Ohlendorff, introduction of dissolved guano by, 311.

Oilcakes, imports of, 153;

source of nitrogen, 153.

Oil-seeds, source of nitrogen, 153.

Oligoclase felspars, 103, 214;

composition of, 103;
potash in, 220.

Organic matter, in bones, 363;

in dung, 228, 260;
in manures, 543;
not necessary for nitrifying organism, 169.

Orthoclase felspars, 103, 214;

composition of, 103;
potash in, 220.

Ox-dung, fertilising ingredients in, for food consumed, 228.

Ox-urine, fertilising ingredients in, 232.

Oxalic acid in guano, action of, 330.

Oxen, excrements of, 280;

food aided by, 280;
solid excreta voided by, 280;
urine voided by, 280.

Oxidation, 79;

products of, 79, 80.

Oxygen, absorbed by plant-roots, 81;

absorbed by soil, 81;
evolved by plants, 11;
necessary for fertility, 81;
necessary for nitrification, 52, 173;
percentage of, in plants, 39;
source of, in plants, 39.

Pabellon de Pica, guano from, 298, 302, 327;

nitrogen in, 330;
phosphoric acid in, 330.

Pacific Islands, guano from, 298.

Pacific Ocean, sea-weed in, 339.

Palagonite as potash manure, 213.

Palm-kernel meal, manurial constituents in, 282.

Pasteur, on fermentation in urine, 255;

on nitrification, 166.

Pastures, accumulation of nitrogen in, 134;

benefited by basic slag, 414;
deficient in lime, 451;
effect of manure on herbage of, 505;
nitrogen in, 158;
permanent, 138, 194
—manuring of, 509;
season influences, 507;
soil influences, 507.

Patagonian guano, 308, 327;

nitrogen in, 330;
phosphoric acid in, 330.

Patent phosphate meal, 405.

Patillos, guano deposits at, 327.

Patos Island, guano deposits at, 328;

phosphoric acid in, 330.

Patterson on superphosphate, 399.

Payen and Boussingault on composition of dried flesh, 425.

Peas, manurial constituents in, 282;

manuring of, 527;
phosphorus in, 205;
source of nitrogen, 153.

Peat, absorbing properties of, 239;

adulterant of guano, 317;
analysis of stable-manure from, 281;
litter, 239;
nitrogen in, 240;
retaining properties of, 240;
soils, 123.

Pelicans, guano from, 297.

Penguin Island guano, 330;

nitrogen in, 330;
phosphoric acid in, 330.

Penguins, guano from, 297.

Percival on carbonic acid in plants, 12.

Peru, guano deposits in, 327;

guano first used in, 297;

nitrate of soda from, 161, 162.

Peruvian guano, 300-306;

appearance of, 303;

composition of, 304-306;

deposits of, 301;

imports of, 151, 297;

source of nitrogen, 151.

Peters and Eichhorn on solvent power of salt, 471.

Petzholdt on sources of plant's nitrogen, 42.

Pfeffer on action of light on plant-growth, 38.

Phœnix Island guano, 309.

Phosphate of iron in Chincha guano, 305.

Phosphate of lime, in Algerian phosphate, 379;

in apatite, 374;
in Belgian phosphate, 377;
in bones, 364;
in Cambridge coprolites, 374;
in Carolina phosphates, 376;
in crust guanos, 379;
in Estremadura phosphate, 375;
in Florida phosphate, 378;
in French phosphates, 379;
in Lahn phosphates, 379;
in Somme phosphate, 378;
reverted in mixing manures, 537.

Phosphates of lime, 385-388, 398;

importance of mechanical condition of, 542.

Phosphates, mineral, 373-381;

imports of, 381;
value as a manure, 380.

Phosphatic guano, 308, 330.

Phosphatic manures, application of, 480.

Phosphoretted hydrogen in farmyard manure, 258.

Phosphoric acid, 199-211;

in ash of plants, 54;
in basic slag, 404;
in bat guano, 325;
in bones, 363;
condition of, in soil, 203;
in cow-dung, 226-228;
in cow excrements, 280;
in cow-urine, 230;
in farmyard manure, 260;
in fish-guano, 321;
fixed by soils, 58;
gain of, 208;
in guano, percentage of, 329, 330;
guano a source of, 202;
in hoofs and horns, 426;
in horse-dung, 226-228;
in horse-urine, 230;
importance of, 88;
loss of, artificial sources of, 206
—by drainage, 206
—in farmyard manure, 208
—in milk, 207
—in sewage, 208
—sources of, in agriculture, 205;
in meat-guano, 324;
mineral sources of, 200;
necessary for plant-growth, 55;
occurrence of, in animals, 205
—in nature, 199
—in plants, 204
—in soil, 203;
in oxen excrements, 280;
in pig-dung, 226, 227;
in pig excrements, 281;
in pig-urine, 230;
position of, in agriculture, 199-211;
relative trade values of, in manures, 400;
in rocks, 202, 211;
in sewage-sludge, 441;
in sheep-dung, 226-228;
in sheep excrements, 280;
in sheep-urine, 230;
statement of, in analyses of manures, 541.

Phosphorite, 201, 374.

Phosphorus, in albuminoids, 205;

in animals, 205;
in beans, 205;
in peas, 205;
in plants, 204;
in pig-iron, 401.

Physical properties of soils, 66-87.

Pichard on action of gypsum on nitrification, 173.

Pig-dung, composition of, 226;

in dry state, 227.

Pig excrements, 281;

composition of, 281.

Pig-manure, 250;

amount produced per day, 251;
mineral matter in, 251;
nitrogen in, 251;
poor in nitrogen, 251.

Pig-urine, composition of, 230

—in dry state, 231.

Pigeon-dung, 320, 325;

analysis of, 331.

Pigs, excrements of, 281;

food consumed by, 281.

Pisagua, nitrate-fields at, 340.

Plant, action of light on, 38;

amount of hydrogen in, 40
—nitrogen in, 40
—oxygen in, 40;
ash constituents of, 53-55;
carbon fixed by, 37, 38;
food, absorption of, by, 55;
phosphoric acid in, 204;
potash in, 216;
proximate composition of, 36;
relation of ammonia to, 48-50;
source of hydrogen in, 40
—nitrogen in, 40-52
—oxygen in, 39, 40.

Plant-food, absorption of, 490;

amount of soluble, in soil, 100;
early theories on source of, 4;
retained by soil, 57.

Plant-roots, grow downwards, 84;

nitrification promoted by, 181;
openness required by, 83;
room required by, 85;
soil in relation to, 84.

Pliny, on lime as a manure, 449;

on salt as a manure, 465.

Pockets a source of phosphoric acid, 202.

Poisons, effect of, on nitrifying organisms, 176.

Polstorff on ash constituents of plants, 53.

Polyhallite, potash in, 220, 420.

Porphyry, in guano, 303;

phosphoric acid in, 202, 211.

Potash, 212-220, 418-423;

in ash of plants, 54;
in barilla, 420;
chloride of, 218;
condition of, in soil, 216;
in cows' excrements, 280;
in drainage-waters, 217;
in farmyard manure, 260;
in felspars, 220;
in fleece, 217;
fixed by soils, 58;
importance of, in soil, 88;
in kelp, 420;
less important than phosphoric acid, 212;
manures, 218, 418-423;
muriate of, 218, 421;
necessary for nitrification, 171;
necessary for plant-growth, 55;
occurrence of, 213;
in ocean, 213;
in oxen excrements, 280;
in pig excrements, 280;
in plants, 216;
position of, in agriculture, 212-220;
relative manurial value of, 556;
Scottish soils supplied with, 419;
in sheep excrements, 280;
soda replaces, 466;
sources of loss of, 217;
in Stassfurt salts, 214;
statement of, in analyses of manures, 542;
in sugar-beet refuse, 219;
sulphate of, 218, 421;
in wood-ashes, 218, 220, 419.

Potash manures, 218, 418-423;

application of, 422, 480
—rate of, 423;
barilla as, 420;
crops suited for, 423;
relative importance of, 418;
soils suited for, 423;
sources of, 419;
Stassfurt salts as, 420;
wood-ashes a source of, 419.

Potassium phosphate in concretionary nodules, 328.

Potassium sulphate, in Chincha guano, 305;

in concretionary nodules, 328.

Potatoes, effect of farmyard manure on, 520;

fertilising ingredients removed from soil by, 485;
grown with covered manure, 289;
Highland Society's experiments on, 518;
manurial constituents in, 282;
manuring of, 517-522
—in Jersey, 529
—influences composition of, 521;
potash removed in, 217;
Rothamsted experiments on, 519, 571.

Precipitated ammonium phosphate in concretionary nodules, 328.

Precipitated phosphate, 330, 387.

Precipitation, treatment of sewage by, 436.

Priestley, discovery of evolution of oxygen by plants, 11;

on nitrogen in plants, 40.

Prussiate of potash, manufacture of, 353.

Pugh on sources of plant-nitrogen, 42.

Punta de Lobos guano, 302;

nitrogen in, 303;
phosphoric acid in, 303.

Punta de Patillos, guano deposits at, 327.

Pyroxene, potash in, 220.

Quartz, evaporation of water from, 99.

Queensland, meat-meal guano from, 324.

Quercitan, experiments of, with roses, 8.

Rape-cake, capable of nitrification, 182;

manurial constituents in, 282.

Rape-seeds, imports of, 153.

Raza Island guano, 328;

phosphoric acid, 330.

Rectified guano, 311.

Relative trade values of phosphoric acid, 400.

Resin in guano, 305.

Retentive power of soils for water, 70-73.

Retrogression, nitrogen lost by, 142.

Reverted phosphates, 389-391;

determination of amount of, 391;
formation 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 composition 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 wheat 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;
experiments, 560-572;
experiments with nitrate of soda at, 347;
experiments 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 drainage of, 189;
nitrates in wheat-soils of, 131, 157;
nitrogen as nitrates in soils of, 129, 198;
nitrogen, decrease 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;
decomposes minerals, 470;
a germicide, 468;
indirect action of, 468;
mechanical 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;
solvent action of, 470;
sources of, 468.

Saltpetre, formation of, 164;

occurrence of, 215;
plantations, 163.

Sand, absorptive power of, 68;

an adulterant of guano, 319;
calcareous, 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 Müntz, on nitrification, 51, 166;

experiments on rate of nitrification by, 185;
on denitrification, 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 temperature favourable for nitrification, 175.

Schoenite, potash in, 220.

Schübler, on absorptive power of soils, 98;

on retentive power of soils, 98.

Schulze on fixers, 246.

Scutch, 427;

manufacture of, 427;
nitrogen in, 427.

Sea-weed, nitric acid in, 339.

Seals, guano from, 297.

Seed, fertilising ingredients lodge in, 491.

Seine, nitrates in waters of, 158.

Sénébier, Jean, on carbon in plants, 12;

on nitrogen in plants, 41.

Sewage, 430-441;

charcoal a filter for, 437;
crops suited for, 434;
denitrification in, 179;
dry matter in, 431;
effects of continued applications of, 433;
filters for, 437;
irrigation with, 431-433;
nitrification in, 166;
nitrogen lost in, 149;
phosphoric acid lost in, 149;
purified by soils, 435;
treatment of, by precipitation, 436;
value of, as a manure, 430.

Sewage-sick land, 433.

Sewage-sludge, 438-441;

as a manure, experiments with, 438;
nitrogen in, 439;
phosphoric acid in, 439;
profitable treatment of, 441;
value of, 439;
water in, 438.

Shale-works, sulphate of ammonia, from, 358.

Shark's Bay guano, 309, 328.

Sheep, excrements of, 280, 281;

solid excreta voided by, 280;
urine voided by, 280.

Sheep-dung, alkalies in, 226;

composition of, in dry state, 227;
most valuable excrement, 227;
nitrogen in, 226;
phosphoric acid in, 226;
water in, 226.

Sheep-manure, 251;

amount produced per day, 251
—per year, 252;
dry matter in, 252;
mineral matter in, 252;
nitrogen in, 252.

Sheep-urine, alkalies in, 230;

composition of, in dry state, 231;
most valuable urine, 231;
nitrogen in, 230;
phosphoric acid in, 230;
water in, 230.

Shoddy, 427;

production of, 152, 425;
nitrogen in, 152, 427.

Sicily, bones from, 360.

Sidney Island guano, phosphoric acid in, 330.

Siemens, Dr, experiments by, with light on plants, 38.

Silica, in ash of plants, 55;

in Chincha guano, 305;
jelly, 169;
necessary for plant-growth, 55.

Silicates, 102;

absorbed by cereals, 494.

Silicic acid fixed by soils, 58.

Simon on humus in soil, 47.

Slaked lime, 454.

Slugs killed by lime, 461.

Smut prevented by lime, 461.

Soda, in ash of plants, 54;

fixed by soils, 58;
necessary for plant-growth, 55;
nitrate of, 332-351;
in salinas, 335;
replaces potash, 466.

Sodium chloride in Chincha Island guano, 305.

Sodium phosphate in concretionary nodules, 328.

Sodium sulphate in concretionary nodules, 328.

Soil, 65-108;

absorptive power of, for water, 67, 98;
acids fixed by, 58-60;
action of lime on, 453;
ammonia absorbed by, 81;
amount of soluble plant-food in, 100;
artificial, 54;
barley, nitrates in, 158;
bases fixed by, 58-60;
best suited for nitrification, 192;
biological properties of, 92-96;
capacity for heat, 76-78;
carbonic acid absorbed by, 81;
chemical composition of, 87-92, 101-107;
colour of, 80;
cropped, nitrates in, 157;
denitrification in, 177;
evaporation from, 71, 72;
farmyard manure, action of, on, 272;
fertilising ingredients in, 87;
fertility of, 65-108;
fineness of, 69-70;
gases in, 100;
hygroscopic power of, 75-76, 99;
improved by humus, 272;
influence of farmyard manure on, 475;
on nitrification, 180;
manures increase fertility of, 474;
nitrates in, amount of, 128-131;
nitrifying organisms in, 179;
distribution of, 179;
nitrogen absorbed by, 81, 82, 131;
nitrogen accumulates, 133;
nitrogen in, amount of, 120-128;
nitrogen least abundant of manurial ingredients in, 270;
nitrogen at various depths in, 156;
oxygen absorbed by, 81;
phosphoric acid in, 203
—condition of, in, 203
—occurrence of, in, 203;
peat, 123;
possesses power of fixing ammonia, 57;
potash in, 215
—condition of, in, 216;
potential fertility of, 549;
power of, for absorbing gases, 81;
relation of, to plant-roots, 84;
retention of plant-food by, 57;
retentive power of, for water, 70-73;
sewage purified by, 435;
shrinkage of, 74;
variation in absorbing powers of, 82;
varieties of, 67;
virgin, 133;
water in, most favourable amount of, 75;
water-logged, 179;
wheat, nitrates in, 157.

Soluble phosphate, 386.

Sombrero phosphate, 308, 328, 330, 379;

phosphoric acid in, 330.

Somme phosphate, 378.

Soot, 428;

application of, rate of, 429;
crops suited by, 429;
nitrogen in, 428.

South America, guano deposits in, 327;

meat-meal guano from, 324.

Starbuck Island guano, 309, 328;

phosphoric acid in, 330.

Stassfurt salts, 214;

potash in, 215, 420.

Stead and Ribsdale on formation of basic slag, 407.

Stoeckhardt, on composition of solid excreta, 226;

on composition of urine, 229.

Storer, Professor, on composition of birds' dung, 331;

on composition of leaves, 242;
on fish-guano, 323;
on nitrogen removed in milk, 147.

Straw, composition of, 238;

imports of, 153;
as litter, 236, 248;
mineral matter in, 238, 243;
nitrogen in, 237, 243;
variation in composition of, 237.

Subsoil, conditions favourable for nitrification in, 181.

Suffolk coprolites, 374.

Sugar-beet refuse, potash in, 219.

Sulphate of alumina, a precipitant of sewage, 437.

Sulphate of ammonia, 352-358;

ammonia in, 355;
application of, 356;
composition of, 355;
a concentrated nitrogenous manure, 356;
converted into nitrates, 356;
from gas-works, 353;
from iron-works, 355;
from shale-works, 354;
manure for cereals, 356;
most easily nitrifiable manure, 191;
production of, 151, 358;
properties of, 355;
source of nitrogen, 149;
sources of, 353, 354, 358;
sulphocyanate of ammonia in, 355.

Sulphate of lime a fixer, 246.

Sulphate of magnesia, an adulterant of guano, 319;

as a fixer, 246.

Sulphate of potash, application of, 422

—rate of, 423;
compared with muriate, 421;
sources of, 218, 420.

Sulphuretted hydrogen from farmyard manure, 258.

Sulphuric acid, action of, on bones, 382

—on guano, 311
—on tricalcic phosphate, 398;
in ash of plants, 54;
as a fixer, 245, 285;
necessary for plant-growth, 55;
superphosphate manufactured with, 384, 388.

Superphosphate, 382-400;

action of, 392-395
—sometimes unfavourable, 395;
application of, 395
—rate of, 397;
composition of, 391;
discovery of, 382;
hastens early growth, 394;
high-class, 392;
low-class, 392;
manufacture of, 383-385
—phosphates suitable for, 384;
medium-class, 391;
production of, 382;
reversion in, 389, 399, 400
—causes of, 389, 390;
reverted in soil, 392.

Surprise Island guano, 328.

Swan Island guano, 328.

Swedes, fertilising ingredients removed from soil by, 485;

manurial constituents in, 282;
manuring of, 514.

Swine-dung, alkalies in, 226;

composition of, 227;
nitrogen in, 226;
phosphoric acid in, 226;
water in, 226.

Swine-urine, alkalies in, 230;

composition of, 231;
nitrogen in, 230;
phosphoric acid in, 230;
water in, 230.

Sydney Island guano, 309.

Syenite, 106;

phosphoric acid in, 202, 211.

Sylvin, potash in, 220.

Symbiosis, 44.

Tamarugal, Pampa de, nitrate deposit in, 340.

Tarapaca, nitrate deposits in, 340.

Temperature necessary for nitrification, 52, 175.

Tetracalcic phosphate, 387;

occurrence of, 387, 405;
solubility of, 387.

Thaer on application of farmyard manure, 275.

Thiocyanates, nitrification in, 182.

Thomas-Gilchrist process of steel-smelting, 402.

Thomas-slag. See Basic slag.

Tillage increases number of plants, 86.

Timor Island guano, 309.

Tobacco, potash in, 217.

Torrefied horn, 426.

Torrefied leather, 428.

Tortola guano, 309.

Trachyte, phosphoric acid in, 202, 211.

Transpiration, by elm-tree, 71;

by oak-tree, 71.

Trees, as pumping-engines, 76;

water transpired by, 71.

Tricalcic phosphate, 386, 398.

Tubercles on roots of plants, 44.

Tull, Jethro, theory of, on plant-growth, 9-11, 69, 109.

Turkey, dung produced by, 331.

Turnips, fertilising ingredients removed from soil by, 485;

manurial constituents in, 282;
manuring of, 510, 511, 513-517;
Rothamsted experiments on growth of, 568.

Twigs, potash in, 217.

Tyrosin, assimilated by plants, 47.

Ulmates in farmyard manure, 259.

Ulmic acid, in farmyard manure, 258;

in humus, 47.

Ulmin in humus, 47.

Uncovered farmyard manure, 263, 289.

Unexhausted manures, valuation of, 549-552, 558.

Unit value of manurial ingredients, 544.

Units for determining commercial value of manures, 554.

Urate of ammonium in Chincha Island guano, 305.

Urea, assimilated by plants, 46;

in farmyard manure, 257;
nitrification in, 182.

Uric acid, experiments with, 46;

in Chincha Island guano, 305.

Urine, 228;

amount voided, 291;
composition of, varies, 228;
contains digested manurial ingredients, 228, 232;
devoid of phosphoric acid, 205;
and dung, composition of, 234;
influence of food on, 229;
nitrification in, 197;
nitrogen in, 292;
potash in, 292;
voided by cows, 280;
voided by oxen, 280;
voided by pigs, 281;
voided by sheep, 280.

Uruguay, meat-meal guano from, 324.

Valuation of manures, 539-559.

Vegetation, desirable to have soil covered with, 194.

Venezuela, guano deposits at, 327.

Ville, Georges, on assimilation of ammonia, 50;

theory of, on source of plant-nitrogen, 41.

Vine, potash removed by, 216.

Virgin soils, 133.

Voelcker, Dr, analysis of apatite, 210

—of farmyard manure, 259;
on action of superphosphate, 395;
on fresh and rotted dung, 261, 286;
on guano, 316;
on salt as a manure, 473.

Voss, Hermann, on manures used, 152.

Wagner, Professor, on, application of basic slag, 416;

assimilation of organic nitrogen, 46;
experiments with basic slag, 408-413;
fineness of basic slag, 409;
manures, 412;
relative manurial value of nitrogen compounds, 556;
solubility of basic slag, 408.

Wallace, Dr, on sewage purification, 436.

Walruses, guano from, 297.

Warington, R,., on ammonia in rain, 49;

on appearance of nitrous organisms, 168;
on conditions favourable for nitrification, 181;
experiments on rate of nitrification, 186;
on composition of farmyard manure, 260;
on manufacture of superphosphate, 383;
on manurial constituents of foods, 282;
on nitrification in alkaline solutions, 197;
on nitrogen in excrements, 233;
on nitrogen in soil, 122;
on potash in wool, 227;
researches of, on nitrification, 35, 52, 166-168, 180, 186.

Water, absorbed by plants, 73;

amount of, transpired by plant-leaves, 56;
an adulterant of guano, 319;
a carrier of plant-food, 55;
in cow-dung, 226
—cow-urine, 230;
from decomposition of farmyard manure, 257;
in horse-dung, 226
—horse-urine, 230;
necessary for plant, 67;
in pig-dung, 226
—pig-urine, 230
—sheep-dung, 226
—sheep-urine, 230;
transpired by elm-tree, 71
—oak-tree, 71.

Water-culture, 54.

Water-logged soils, 179.

Waterloo, bones from, 360.

Way, Thomas, on retention of plant-food by soil, 57, 59;

on sewage, 437.

West Indies, guano from, 298.

Whales, guano from, 322.

Wheat, fertilising ingredients removed from soil by, 485;

Flitcham experiments on, 500;
manurial constituents in, 282;
manuring of, 499-501
nitrogen removed in crop of, 145;
requires nitrogenous manures, 499;
Rothamsted experiments on, 500, 562-565;
a source of nitrogen, 153.

Wheat soils, nitrates in, 157.

Wheat-straw, analysis of stable manure made from, 283;

composition of, 238;
manurial constituents in, 282.

White clover, growth of, promoted by lime, 451.

Wiegmann on ash constituents of plants, 53.

Wilfarth on nitrogen in plants, 44.

Wilting, 73.

Winogradsky, on nitrification, 52, 167, 169, 197;

on organisms in soil, 94.

Wolff on, analysis of manure-heap drainings, 290;

composition of fresh and rotten dung, 288;
assimilation of organic nitrogen by plants, 47;
relative manurial value of manurial compounds, 556;
urine, 232.

Wood-ashes as potash manure, 218, 419.

Woodhouse, researches of, on nitrogen in plants, 41.

Wool, capable of nitrification, 182;

potash in, 217.

Wool-waste, 427;

nitrogen in, 427.

Woolney, on organisms in soils, 93, 95;

on water in soils, 75.

Wrightson, Professor, on application of basic slag, 414.

Yeast, 94.

Yorkshire, bones first used in, 359.

Zeolites, potash in, 220

FOOTNOTES:

INDEX.