The formation of nitrites and nitrates from ammonia and its compounds in the soil, was formerly held to be a purely chemical process, until Schloesing and Mintz suggested in 1877 that it was biological.
Rend., 1904 seq.) by fractional crystallization of the nickel double nitrates, the ethyl sulphates, and the bismuth double nitrates of the terbium earths.
The green plant prefers as a rule nitrates of various metals, such as calcium, magnesium or potassium.
Long ago the view that this gas might be the source of the combined nitrogen found in different forms within the plant, was critically examined, particularly by Boussingault, and later by Lawes and Gilbert and by Pugh, and it was ascertained to be erroneous, the plants only taking nitrogen into their substance when it is presented to their roots in the form of nitrates of various metals, or compounds of ammonia.
While they are quite capable of taking up nitrates from the soil where and so long as these are present, they can grow and thrive in soil which contains no combined nitrogen at all, deriving their supplies of this element in these cases from the air.
Deficiency of nutritive salts, especially nitrates and phosphates; the presence of poisonous salts of iron, copper, &c., or (in the soil about the roots of trees in towns) of coal-gas and so forth.
The salts of all the metals of this group usually crystallize well, the chlorides and nitrates dissolve readily in water, whilst the carbonates, phosphates and sulphates are either very sparingly soluble or are insoluble in water.
This result is partly due to their period of accumulation and growth extending even months after the period of collection by the ripening cereals has terminated, and at the season when nitrification within the soil is most active, and the accumulation of nitrates in it is the greatest.
Thus from ethyl alcohol there can be prepared compounds, termed esters, or ethereal salts, exactly comparable in structure with corresponding salts of, say, potassium; by the action of the phosphorus haloids, the hydroxyl group is replaced by a halogen atom with the formation of derivatives of the type R Cl(Br,I); nitric acid forms nitrates, R O NO 2; nitrous acid, nitrites, R O NO; sulphuric acid gives normal sulphates R 2 SO 4, or acid sulphates, R SO 4 H.
Oxygen, recognized by its power of igniting a glowing splinter, results from the decomposition of oxides of the noble metals, peroxides, chlorates, nitrates and other highly oxygenized salts.
It converts many metallic oxides into mixtures of nitrates and nitrites, and attacks many metals, forming nitrates and being itself reduced to nitric oxide.
Its salts may be obtained in some cases by heating the corresponding nitrates, but the method does not give good results.
- These are the materials which are utilized by the vegetable plankton in the synthesis of living material: they are water, carbonic acid, nitrates and nitrites of calcium, magnesium and other earthy and alkaline metals, phosphates, silica, traces of salts containing iron, sulphur, potassium and a few other elements.
The source of the carbon of organic tissues is carbonic acid; that of the nitrogen in the proteids is the nitrates, nitrites and salts of ammonia dissolved in sea-water; the material of the shells or other skeletons is the silica, phosphate and calcium of the salts of sea-water (and, in rare cases, the salts of strontium).
Mineral nitrogenous compounds (nitrates, nitrites and ammonia) are much more rare.
First of all we consider inorganically combined nitrogen (as nitrates and nitrites chiefly), since upon this depends all the life of the ocean.
The relative abundance of nitrates and nitrites at the bottom of deep oceans as compared with the surface can be explained in the same way, for at the bottom the temperature is about zero Centigrade and the activities of the denitrifying bacteria are practically suspended.
The dead bodies of organisms fall down from the surface and are slowly resolved into products of putrefaction, which gradually pass into the mineral forms, nitrates, carbonic acid and ash.
Its principal imports are coffee (of which it is the greatest continental market), tea, sugar, spices, rice, wine (especially from Bordeaux), lard (from Chicago), cereals, sago, dried fruits, herrings, wax (from Morocco and Mozambique), tobacco, hemp, cotton (which of late years shows a large increase), wool, skins, leather, oils, dyewoods, indigo, nitrates, phosphates and coal.
Basic nitrates, e.g.
In one process the purified ore is disintegrated with hot nitric acid to produce nitrates, which are then converted into sulphates by evaporation with sulphuric acid.
(I) Commercially pure tin is treated with nitric acid, which converts the tin proper into the insoluble metastannic acid, while the copper, iron, &c., become nitrates; the metastannic acid is washed first with dilute nitric acid, then with water, and is lastly dried and reduced by fusion with black flux or potassium cyanide.
GUNCOTTON, an explosive substance produced by the action of strong nitric acid on cellulose at the ordinary temperature; chemically it is a nitrate of cellulose, or a mixture of nitrates, according to some authorities.
The nitrates are also very insoluble substances, all the so-called solvents merely converting them into jelly.
The products of the action of nitric acid on cellulose are not nitro compounds in the sense that picric acid is, but are nitrates or nitric esters.
The 1 The composition of the cellulose nitrates was reviewed by G.
On its thoroughness depends the removal of small quantities of products other than the nitrates, for instance, some sulphates and products from impurities contained in the original cellulose.
The nitrate of this base (known as nitron) is so insoluble that nitrates may be gravimetrically estimated with its help. These bases combine with the alkyl iodides to yield quaternary ammonium salts.
The materials are generally used in the form either of oxides (lead, zinc, silica, &c.) or of salts readily decomposed by heat, such as the nitrates or carbonates.
All other metals, including palladium, are dissolved as nitrates, the oxidizing part of the reagent being generally reduced to oxides of nitrogen.
Leguminous crops take some of the nitrogen which they require from the air, but most plants obtain it from the nitrates present in the soil.
The sulphur exists in the soil chiefly in the form of sulphates of magnesium, calcium and other metals; the phosphorus mainly as phosphates of calcium, magnesium and iron; the potash, soda and other bases as silicates and nitrates; calcium and magnesium carbonates are also common constituents of many soils.
That: the action of living organisms is the cause of the production of nitrates is supported by the fact that the change does not occur when the soil is heated nor when it is treated with disinfectants which destroy or check the growth and life of bacteria.
The process resulting in the formation of nitrates in the soil is spoken of as nitrification.
Nitrates are very soluble in water and are therefore liable to be washed out of the soil by heavy rain.
They are, however, very readily absorbed by growing plants, so that in summer, when nitrification is most active, the nitrates produced are usually made use of by crops before loss by drainage takes place.
There is also another possible source of loss of nitrates through the activity of denitrifying bacteria.
These organisms reduce nitrates to nitrites and finally to ammonia and gaseous free nitrogen which escapes into the atmosphere.
They can, however, only carry on their work extensively under anaerobic conditions, as in waterlogged soils or in those which are badly tilled, so that there is but little loss of nitrates through their agency.
Sal, salt, petra, a rock), the commercial name given to three naturally occurring nitrates, distinguished as (1) ordinary saltpetre, nitre, or potassium nitrate, (2) Chile saltpetre, cubic nitre, or sodium nitrate, (3) wall-saltpetre or calcium nitrate.
These nitrates generally occur as efflorescences caused by the oxidation of nitrogenous matter in the presence of the alkalies and alkaline earths.
Ordinary Saltpetre or Potassium Nitrate, KN03, occurs, mingled with other nitrates, on the surface and in the superficial layers of the soil in many countries, especially in certain parts of India, Persia, Arabia and Spain.
Within these limits are to be found most of the minerals known - gold, silver, quicksilver, copper, lead, zinc, iron, manganese, wolfram, bismuth, thorium, vanadium; mica, coal, &c. On or near the coast are coal, salt, sulphur, borax, nitrates and petroleum.
Internal strife at first prevented the development of her resources, and then when the export of guano and nitrates supplied her treasury with an abundance of funds the money was squandered on extravagant enterprises and in corrupt practices.
The metal is soluble in solutions of chlorine, bromine, thiosulphates and cyanides; and also in solutions which generate chlorine, such as mixtures of hydrochloric acid with nitric acid, chromic acid, antimonious acid, peroxides and nitrates, and of nitric acid with a chloride.
The freezing of the soil in winter, which at first sight seems a drawback, retains the soluble nitrates which might otherwise be drained out.
The acid is found to exist to a slight extent in the free condition in some waters, but chiefly occurs in combination with various metals, as nitrates, principally as nitre or saltpetre, KN03, and Chile saltpetre, NaNO 3.
It may be purified by redistillation over barium and silver nitrates, followed by treatment of the distillate with a stream of ozonized air.
The salts of nitric acid, known as nitrates, are mostly readily soluble in water and crystallize well.
Both are remarkable for the quantity of nitrates and phosphates they contain.