Margarine, 46.

Marl, 245.

Mexican guano, 207.

Mica, 88.

Mica slate, 91.

Milk, composition of, 283.
Curding of, 51.

Mineral constituents of plants, 9, 63.

Mineral manures, 226.

Mineral matters in different crops, 270.
In animals, 281.

Moisture, influence of, on germination, 55.

Mucilage, 44.

Natrolite, 90.

New Island guano, 208.

Niger cake, 286.

Night-soil, 217.

Nitrate of potash, 229.

Nitrate of soda, 229, 260.

Nitric acid, absorbtion of, by plants, 30, 38.
Decomposition of, by plants, 62.
In drainage water, 112.
In dew, 19.
In air, 17.
In fog, 19.
Production of, 11, 33.

Nitrification, 11.

Nitrogen, amount in a six-course rotation, 160.
Amount of, in different crops, 270.
Presence in the atmosphere, 11.
Properties of, 11.
Proportion of, in plants, 11.

Nitrogenous constituents of plants, 48, 286.

Nitrogenous constituents of animals, 48, 281.

Oats, 286.
Proportion of ash in, 68, 70.

Oil-cakes, 195, 286.

Oils, sweet principle of, 47.

Oily matters, 46.

Oleic acid, 47.

Oleine, 46.

Oligoclase, 86.

Oolitic limestone, 96.

Organic constituents of plants, 8.
Sources of the, 13, 20.

Organic constituents of soils, 103.

Orthoclase, 86.

Oxide of iron in rocks and soils, 87, 107.
Of manganese, 87.

Oxygen, evolution of, by plants, 58.
Influence of, on germination, 55.
Presence in atmosphere, 12.
Properties of, 12.
Proportion of, in plants, 12.

Pacquico Guano, 207.

Paring, improvement of soils by, 146.

Patagonian guano, 207.

Pea-nut cake, 286.

Peas, 286.

Peat, as a manure, 203.

Peat, use of, in dung-heaps, 184.

Pectic acid, 46.

Pectine, 46.

Peruvian Guano, 205, 207, 209.
Upper, 207, 213.

Phosphate of lime, 96, 233.
Value of, 258.

Phosphates, insoluble, 258.
Soluble, 237, 260.

Phospho-Peruvian guano, 243.

Phosphuretted hydrogen in air, 19.

Pigeons' dung, 216.

Plants, Albuminous constituents of, 48.
Amylaceous constituents of, 40.
Ash of, 64, 73.
Classification of, 81.
Inorganic constituents of, 9, 34, 38, 63.
Oily constituents of, 46.
Organic constituents of, 8.
Proximate constituents of, 40.
Saccharine constituents of, 40.

Poppy cake, 196, 286.

Potash, carbonate of, 232.
Muriate of, 231.
Nitrate of, 229.
Plants, 82.
Salts, 231.

Potato, 286.

Poudrette, 217.

Proximate constituents of plants, 40.

Pyro