Ammonia Sentence Examples

Berthollet in 1788 by acting with ammonia on precipitated silver oxide.

On heating in hydrogen, ammonia or carbon monoxide, or with carbon or sodium, it is reduced to the metallic state.

If it possesses an alkaline or acid reaction, it must be tested in the first case for ammonia, and in the second case for a volatile acid, such as sulphuric, nitric, hydrochloric, &c.

Nitrogen may be detected by the evolution of ammonia when the substance is heated with soda-lime.

Boron fluoride also combines with ammonia gas, equal volumes of the two gases giving a white crystalline solid of composition BF 3 NH 3 i with excess of ammonia gas, colourless liquids BF 3.2NH 3 and BF 3.3NH 3 are produced, which on heating lose ammonia and are converted into the solid form.

It is decomposed by heat into the oxide and water, and is soluble in ammonia but not in excess of dilute potassium hydroxide; this latter property serves to distinguish it from zinc hydroxide.

The independence of the two is suggested by the fact that fungi can live, thrive and grow in nutritive media which contain carbohydrates together with certain salts of ammonia, but which are free from proteids.

It is also readily soluble in solutions of the caustic alkalis, slightly soluble in aqueous ammonia solution, and almost insoluble in sodium carbonate solution.

A curious property is to be observed when a crystal of pharmacosiderite is placed in a solution of ammonia - in a few minutes the green colour changes throughout the whole crystal to red; on placing the red crystal in dilute hydrochloric acid the green colour is restored.

On boiling their solution in caustic alkalis, ammonia is liberated.

The powder is soluble in alcohol and strong solutions of alkalis, such as ammonia.

Gradually, however, the technical difficulties were overcome and success assured, largely as a result of improved methods worked out by Mond for the recovery of the ammonia.

It unites readily with ammonia gas forming a white crystalline solid of composition 2BC13.3NH3.

The fungus seems to do better when supplied with compounds of ammonia.

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.

The picrate so formed is then decomposed by ammonia.

Heating spirits of hartshorn, he was able to collect "alkaline air" (gaseous ammonia), again because he was using mercury in his pneumatic trough; then, trying what would happen if he passed electric sparks through the gas, he decomposed it into nitrogen and hydrogen, and "having a notion" that mixed with hydrochloric acid gas it would produce a "neutral air," perhaps much the same as common air, he synthesized sal ammoniac. Dephlogisticated air (oxygen) he prepared in August 1774 by heating red oxide of mercury with a burning-glass, and he found that in it a candle burnt with a remarkably vigorous flame and mice lived well.

Liquid ammonia possesses strong ionizing powers, and solutions of salts in liquid ammonia have been much studied.

The solution on the addition of ammoniacal silver nitrate behaves similarly to that of potassium pentathionate, but differs from it in giving an immediate precipitate of sulphur with ammonia, whereas the solution of the pentathionate only gradually becomes turbid on standing.

Natural gas is found to consist mainly of the lower paraffins, with varying quantities of carbon dioxide, carbon monoxide, hydrogen, nitrogen and oxygen, in some cases also sulphuretted hydrogen and possibly ammonia.

It absorbs ammonia readily, forming Ru2C16.7NH,.

For example, one volume of oxygen combined with two of hydrogen to form two volumes of steam, three volumes of hydrogen combined with one of nitrogen to give two volumes of ammonia, one volume of hydrogen combined with one of chlorine to give two volumes of hydrochloric acid.

One other instance may be given; the equation 2NH3=N2+3H2 represents the decomposition of ammonia gas into nitrogen and hydrogen gases by the electric spark, and it not only conveys the information that a certain relative weight of ammonia, consisting of certain relative weights of hydrogen and nitrogen, is broken up into certain relative weights of hydrogen and nitrogen, but also that the nitrogen will be contained in half the space which contained the ammonia, and that the volume of the hydrogen will be one and a half times as great as that of the original ammonia, so that in the decomposition of ammonia the volume becomes doubled.

A masterly device, initiated by him, was to collect gases over mercury instead of water; this enabled him to obtain gases previously only known in solution, such as ammonia, hydrochloric acid, silicon fluoride and sulphur dioxide.

It is washed by ejecting a jet of water, ammonia or other prescribed liquid on to the side of the filter paper until the paper is nearly full.

When boiled with calcium chloride and ammonia, salicylic acid gives a precipitate of insoluble basic calcium salicylate, C 6 H 4 ‹ 0 2 i Ca, a reaction which serves to distinguish it from the isomeric metaand para-hydroxybenzoic acids.

It behaves as a powerful reducing agent, and on hydrolysis with dilute mineral acids is decomposed into formaldehyde and hydroxylamine, together with some formic acid and ammonia, the amount of each product formed varying with temperature, time of reaction, amount of water present, &c. This latter reaction is probably due to some of the oxime existing in the form of the isomeric formamide HCO NH 2.

A boiling solution of caustic potash hydrolyses it to ammonia and succinic acid.

The conversion of nitrogen into ammonia by electricity has received much attention, but the commercial aspect appears to have been first worked out by de Hemptinne in 1900, who used both the spark and silent discharge on mixtures of hydrogen and nitrogen, and found that the pressure and temperature must be kept low and the spark gap narrow.

For the so-called nitrogen iodide see Ammonia.

Nitrogen combines with hydrogen to form ammonia, NH 3, hydrazine, N 2 H 4, and azoimide, N 3 H (qq.v.); the other known hydrides, N 4 H 4 and N5H5, are salts of azoimide, viz.

The silver salt is a bright yellow solid, soluble in dilute sulphuric and nitric acids, and may be crystallized from concentrated solutions of ammonia.

Geisel (Ber., 1904, 37, p. 1 573; 1905, 38, p. 2659), who also obtained it by dissolving sulphur in liquid ammonia.

P For sulphonic acids containing nitrogen see Ammonia.

Among the larger private establishments there existed in the same year seven breweries, one brandy distillery, two jam, two soap and candle factories, two building and furniture works, a factory for spinning thread, one iron and steel works, one paper and one ammonia and soda factory, and one mineral-oil refinery.

The oxides are then converted into double sulphates which are separated from each other by repeated fractional crystallization or by fractional precipitation with ammonia or some other base.

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.

Boiling with dilute mineral acids, or baryta water, decomposes albumins into carbon dioxide, ammonia and fatty aminoand other acids.

In the case of substances like ammonia and acetic acid, where the dissociation is very small, I - a is nearly equal to unity, and only varies slowly with dilution.

When exposed to air the latex gradually undergoes putrefactive changes accompanied by coagulation of the caoutchouc. The addition of a small quantity of ammonia or of formalin to some latices usually has the effect of preserving them for a considerable time.

Alkalis have little effect on it under ordinary circumstances, although prolonged contact with ammonia results in a partial change.

Before it is put in, the article is roughly put together, and the expansion of the included air forces the rubber into contact with the internal surface of the mould, or a little carbonate of ammonia is enclosed.

In order to make spongy or porous rubber, some material is incorporated which will give off gas or vapour at the vulcanizing temperature, - such as carbonate of ammonia, crystallized alum, and finely ground damp sawdust.

Klaproth in the mineral honeystone, which is the aluminium salt of the acid, The acid may be prepared by warming honeystone with ammonium carbonate, boiling off the excess of the ammonium salt and adding ammonia to the solution.

The corresponding hydrate, Pb(OH)2, is obtained as a white crystalline precipitate by adding ammonia to a solution of lead nitrate or acetate.

Heating or exposure to sunlight reduces it to the red oxide; it fires when ground with sulphur, and oxidizes ammonia to nitric acid, with the simultaneous formation of ammonium nitrate.

Lead sesquioxide, Pb203, is obtained as a reddish-yellow amorphous powder by carefully adding sodium hypochlorite to a cold potash solution of lead oxide, or by adding very dilute ammonia to a solution of red lead in acetic acid.

The borate, Pb 2 B 6 0 1 u 4H20, is obtained as a white precipitate by adding borax to a lead salt; this on heating with strong ammonia gives PbB2044H2.

They act as reducing agents, silver nitrate in the presence of ammonia being rapidly reduced to the condition of metallic silver.

These are colourless crystalline compounds, which are most readily prepared by passing ammonia gas into an ethereal solution of the aldehyde.

By passing acrolein vapour into ammonia, acrolein ammonia, C 6 H 9 NO, is obtained.

With ammonia, benzaldehyde does not form an aldehyde ammonia, but condenses to hydrobenzamide, (C 6 H 5 CH) 3 N 2, with elimination of water.

These are oxidized and precipitated conjointly by excess of ammonia.

Both iodides combine with ammonia.

The solutions are oxidized, precipitated with ammonia, the precipitate dissolved in hydrochloric acid, and re-thrown down by boiling with sodium sulphate.

Ammonia is also active, but not quite in the same manner as the alkali hydroxides.

Nascent hydrogen reduces cyanamide to ammonia and methylamine.

The cornmercial product (which is known in Germany as "Kalkstickstof") contains from 14 to 22% of nitrogen, which is liberated as ammonia when the substance is treated with water; to this decomposition it owes its agricultural value.

It may be separated by shaking out with dilute sulphuric acid, and then precipitating the sulphuric acid solution with potassium bichromate, the resulting acridine bichromate being decomposed by ammonia.

These substances condense to form tetra-aminotriphenylmethane, which, on heating with acids, loses ammonia and yields diaminodihydrophenylacridine, from which benzoflavin is obtained by oxidation.

It decomposes ammonia at a red heat, liberating hydrogen and yielding a compound containing silicon and nitrogen.

It combines directly with ammonia to form the compound SiF 4 2NH,, and is absorbed by dry boric acid and by many metallic oxides.

It combines directly with ammonia gas to form SiC1 4 .

It unites directly with ammonia gas yielding a compound of variable composition.

Triethyl silicol, (C2H5),Si OH, is a true alcohol, obtained by condensing zinc ethyl with silicic ester, the resulting substance of composition, (C2H5)3 SiOC2H51 with acetyl chloride yielding a chloro-compound (C2H5)3SiC1, which with aqueous ammonia yields the alcohol.

Silicobenzoic acid, C 6 H 5 S10.0H, results from the action of dilute aqueous ammonia on phenyl silicon chloride (obtained from mercury diphenyl and silicon tetrachloride).

They show all the reactions of esters, being readily hydrolysed by caustic alkalis, and reacting with ammonia to produce carhamic esters and urea.

When heated with ammonia it yields guanidine, and on boiling with alcoholic potash it yields potassium carbonate.

When heated with ammonia it yields urethane.

Wohl forms the oxime and converts it into an acetylated nitrile by means of acetic anhydride and sodium acetate; ammoniacal silver nitrate solution removes hydrocyanic acid and the resulting acetate is hydrolysed by acting with ammonia to form an amide, which is finally decomposed with sulphuric acid.

The compounds of ammonia thus formed from the complex substances by many varied kinds of micro-organisms are ultimately oxidized into nitrates.

It is only when these conditions are attended to that decay and nitrification of dung, guano, fish-meal, sulphate of ammonia and other manures take place, and the constituents which they contain become available to the crops for whose benefit they have been applied to the land.

These organisms reduce nitrates to nitrites and finally to ammonia and gaseous free nitrogen which escapes into the atmosphere.

The peculiar properties of snuff are dependent on the presence of free nicotine, free ammonia and the aromatic principles developed during fermentation.

Zinc is also soluble in soda and potash solutions, but not in ammonia.

With ammonia and alkaline bromides and iodides double salts are formed.

In the case of acetate the precipitation is quite complete; from a sulphate or chloride solution the greater part of the metal goes into the precipitate; in the presence of a sufficiency of free HC1 the metal remains dissolved; sulphide of ammonium precipitates the metal completely, even in the presence of ammonium salts and free ammonia.

Rejecting the old notion that plants derive their nourishment from humus, he taught that they get carbon and nitrogen from the carbon dioxide and ammonia present in the atmosphere, these compounds being returned by them to the atmosphere by the processes of putrefaction and fermentation - which latter he regarded as essentially chemical in nature - while their potash, soda, lime, sulphur, phosphorus, &c., come from the soil.

Of the carbon dioxide and ammonia no exhaustion can take place, but of the mineral constitutents the supply is limited because the soil cannot afford an indefinite amount of them; hence the chief care of the farmer, and the function of manures, is to restore to the soil those minerals which each crop is found, by the analysis of its ashes, to take up in its growth.

On this theory he prepared artificial manures containing the essential mineral substances together with a small quantity of ammoniacal salts, because he held that the air does not supply ammonia fast enough in certain cases, and carried out systematic experiments on ten acres of poor sandy land which he obtained from thr town of Giessen in 1845.

Ti 3 N 4 is a copper-coloured powder obtained by heating the ammonio-chloride TiC1 4.4NH 3 in ammonia.

TiN 2 is a dark blue powder obtained when the oxide is ignited in an atmosphere of ammonia; while TiN is obtained as a bronze yellow mass as hard as the diamond by heating the oxide in an atmosphere of nitrogen in the electric furnace.

The pure salt is dissolved in hot water and decomposed with ammonia to produce a slightly ammoniacal hydrated oxide; this, when ignited in platinum, leaves pure TiO 2 in the form of brownish lumps, the specific gravity of which varies from 3.9 to 4.25, according to the temperature at which it was kept in igniting.

It forms addition compounds similar to those formed by stannic chloride, and combines with ammonia to form TiCl 4.8NH 3 and TiC1 4.6NH 3, both of which with liquid ammonia give titanamide, Ti(NH2)4.

Acid solutions of titanates are not precipitated by sulphuretted hydrogen; but ammonium sulphide acts on them as if it were ammonia, the sulphuretted hydrogen being liberated.

They are ionized in aqueous solution to a much greater extent than ammonia, the quaternary ammonium bases being the most ionized, and the secondary bases being more strongly ionized than the primary or tertiary bases.

Ladenburg, Ber., 1886, 19, p. 783); by heating the esters of nitric acid with alcoholic ammonia at 10o C. (0.

By the action of ammonia on the alkyl iodides a complex mixture of primary, secondary and tertiary amines, along with a quaternary ammonium salt, is obtained, the separation of which is difficult.

Tetramethylammonium iodide, N(CH 3) 4 I, is the chief product obtained by the action of methyl iodide on ammonia (Hofmann).

Tafel, Ber., 1886, 19, p. 1924), by distilling the amido-acids with lime, by heating phenols with zinc chloride ammonia (V.

It is to be noted that only traces of the aromatic amines are produced by heating the halogen substituted benzenes with ammonia, unless the amino group be situated in the side chain, as in the case of benzylamine.

The Coffey still is one of the most effective and is employed in the spirit, ammonia, coal-tar and other industries.

The first portion of the distillate brings over the gases dissolved in the water, ammonia and other volatile impurities, and is consequently rejected; scarcely two-fifths of the entire quantity of water can be safely used as pure distilled water.

It is a white solid, which combines with gaseous ammonia to form SrC1 2.8NH 3, and when heated in superheated steam it decomposes with evolution of hydrochloric acid.

It is readily decomposed by water, with liberation of ammonia.

Oxamide, (CONH 2) 2, is best prepared by the action of ammonia on the esters of oxalic acid.

Small, stimulating doses, and repeated, are good, but stimulation can be more effectively produced by ammonia or strychnine.

Hypodermic injection of strychnine, in some cases as much as one to two grains (but not into a vein!), has in some cases had good results; but injection of ammonia, instead of doing any good, has disastrous sloughing results.

With concentrated ammonia auric oxide forms a black, highly explosive compound of the composition AuN2H3.3H20, named " fulminating gold "; this substance is generally considered to be Au(NH 2)NH.

This salt is prepared by precipitating a solution of gold in aqua regia by ammonia, and then introducing the well-washed precipitate into a boiling solution of potassium cyanide.

Hampe prepared chemically pure bismuth by fusing the metal with sodium carbonate and sulphur, dissolving the bismuth sulphide so formed in nitric acid, precipitating the bismuth as the basic nitrate, redissolving this salt in nitric acid, and then precipitating with ammonia.

These compounds closely resemble the trichloride in their methods of preparation and their properties, forming oxyhaloids with water, and double compounds with ammonia, &c.

But the two substances were generally confounded as "fixed alkali" (carbonate of ammonia being "volatile alkali"), till Duhamel du Monceau in 1736 established the fact that common salt and the ashes of seaplants contain the same base as is found in natural deposits of soda salts ("mineral alkali"), and that this body is different from the "vegetable alkali" obtained by incinerating land plants or wood (pot-ashes).

In modern chemistry alkali is a general term used for compounds which have the property of neutralizing acids, and is applied more particularly to the highly soluble hydrates of sodium and potassium and of the three rarer "alkali metals," caesium, rubidium and lithium, also to aqueous ammonia.

For this purpose the zero or pure blue is represented by a solution of i part of copper sulphate and 9 parts of ammonia in 190 parts of water.

The brine is cooled in a tank filled with spiral pipes, in which anhydrous ammonia, previously liquefied by compression, is vaporized in vacuo at the atmospheric temperature by the sensible heat of the returncurrent of brine, whose temperature has been slightly raised in its passage through the circulating tubes.

Although at the present time a marvellous improvement has taken place all round in the quality of the carbide produced, the acetylene nearly always contains minute traces of hydrogen, ammonia, sulphuretted hydrogen, phosphuretted hydrogen, silicon hydride, nitrogen and oxygen, and sometimes minute traces of carbon monoxide and dioxide.

The ammonia found in the acetylene is probably partly due to the presence of magnesium nitride in the carbide.

On decomposition by water, ammonia is produced by the action of steam or of nascent hydrogen on the nitride, the quantity formed depending very largely upon the temperature at which the carbide is decomposed.

The formation of nitrides and cyanamides by actions of this kind and their easy conversion into ammonia is a useful method for fixing the nitrogen of the atmosphere and rendering it available for manurial purposes.

In experiments with these various bodies it is found that they are all of them effective in also ridding the acetylene of the ammonia and sulphuretted hydrogen, provided only that the surface area presented to the gas is sufficiently large.

Where the production of acetylene is going on on a small scale this method of purification is undoubtedly the most convenient one, as the acid present absorbs the ammonia, and the copper salt converts the phosphuretted and sulphuretted hydrogen into phosphates and sulphides.

The vessel, however, which contains this mixture has to be of earthenware, porcelain or enamelled iron on account of the free acid present; the gas must be washed after purification to remove traces of hydrochloric acid, and care must be taken to prevent the complete neutralization of the acid by the ammonia present in the gas.

The second process is one patented by Fritz Ullmann of Geneva, who utilizes chromic acid to oxidize the phosphuretted and sulphuretted hydrogen and absorb the ammonia, and this method of purification has proved the most successful in practice, the chromic acid being absorbed by kieselgiihr and the material sold under the name of "Heratol."

Dr P. Wolff has found that when this is used on the large scale there is a risk of the ammonia present in the acetylene forming traces of chloride of nitrogen in the purifying-boxes, and as this is a compound which detonates with considerable local force, it occasionally gives rise to explosions in the purifying apparatus.

If, however, the gas be first passed through a scrubber so as to wash out the ammonia this danger is avoided.

This anhydrous chloride is reduced to a lower chloride, of composition SmC1 2, when heated to a high temperature in a current of hydrogen or ammonia (Matignon and Cazes, Coupes rendus, 2906, 142, p. 183).

The double fluoride is decomposed with hot concentrated sulphuric acid; the mixed sulphate is dissolved in water; and the zirconia is precipitated with ammonia in the cold.

The precipitate, being difficult to wash, is (after a preliminary washing) re-dissolved in hydrochloric acid and re-precipitated with ammonia.

The iodide combines with liquid ammonia to form ZrI 4.8NH 3 i and with ether to give Zr14.4(C2H5)20.

Nitric acid and lower nitrogen oxides are present, being formed by electrical discharges, and by the oxidation of atmospheric ammonia by ozone.

Ammonia is also present, but in very varying amounts, ranging from 135 to 0 I parts (calculated as carbonate) in a million parts of air.

Ammonia is carried back to the soil by means of rain, and there plays an important part in providing nitrogenous matter which is afterwards assimilated by vegetable life.

All soluble orthophosphates give with silver nitrate a characteristic yellow precipitate of silver phosphate, Ag 3 PO 4, soluble in ammonia and in nitric acid.

Metaphosphoric acid can be distinguished from the other two acids by its power of coagulating albumen, and by not being precipitated by mag nesium and ammonium chlorides in the presence of ammonia.

Water decomposes it to give hydrogen free from ammonia and acetylene, i gram yielding about loo ccs.

It combines with gaseous ammonia and forms crystalline compounds with certain alcohols.

The mineral brushite, CaHPO 4.2H 2 0, which is isomorphous with the acid arsenate pharmacolite, CaHAs04.2H20, is an acid phosphate, and assumes monoclinic forms. The normal salt may be obtained artificially, as a white gelatinous precipitate which shrinks greatly on drying, by mixing solutions of sodium hydrogen phosphate, ammonia, and calcium chloride.

Ammonia is found in small quantities as the carbonate in the atmosphere, being produced from the putrefaction of nitrogenous animal and vegetable matter; ammonium salts are also found in small quantities in rain-water, whilst ammonium chloride (sal-ammoniac) and ammonium sulphate are found in volcanic districts; and crystals of ammonium bicarbonate have been found in Patagonian guano.

Ammonia can be synthesized by submitting a mixture of nitrogen and hydrogen to the action of the silent electric discharge, the combination, however, being very imperfect.

Large quantities of ammonia and ammonium salts are now obtained from the ammoniacal liquor of gas-works.

All the ammonia contained in an aqueous solution of the gas may be expelled by boiling.

Ammonia gas has the power of combining with many substances, particularly with metallic halides; thus with calcium chloride it forms the compound CaCl 2.8NH 3, and consequently calcium chloride cannot be used for drying the gas.

Faraday was first able to liquefy ammonia.

At a red heat ammonia is easily decomposed into its constituent elements, a similar decomposition being brought about by the passage of electric sparks through the gas.

Chlorine takes fire when passed into ammonia, nitrogen and hydrochloric acid being formed, and unless the ammonia be present in excess, the highly explosive nitrogen chloride NC1 3 is also produced.

The hydrogen in ammonia is capable of replacement by metals, thus magnesium burns in the gas with the formation of magnesium nitride Mg3N2, and when the gas is passed over heated sodium or potassium, sodamide, NaNH 2, and potassamide, KNH 2, are formed.

The aqueous solution of ammonia is very basic in its reactions, and since it is a weak electrolyte, one must assume the solution to contain a certain amount of ammonium hydroxide NH 4 OH, although it is probably chiefly composed of a solution of ammonia in water.

Aldehydes also combine directly with ammonia.

The salts produced by the action of ammonia on acids are known as the ammonium salts and all contain the compound radical ammonium (NH 4).

By the addition of sodium amalgam to a concentrated solution of ammonium chloride, the so-called ammonium amalgam is obtained as a spongy mass which floats on the surface of the liquid; it decomposes readily at ordinary temperatures into ammonia and hydrogen; it does not reduce silver and gold salts, a behaviour which distinguishes it from the amalgams of the alkali metals, and for this reason it is regarded by some chemists as being merely mercury inflated by gaseous ammonia and hydrogen.

Ammonium iodide, NH 4 I, can be prepared by the action of hydriodic acid on ammonia.

Ammonium chlorate, NH 4 C10 3, is obtained by neutralizing chloric acid with either ammonia or ammonium carbonate, or by precipitating barium, strontium or calcium chlorates with ammonium carbonate.

The aqueous solutions of all the carbonates when boiled undergo decomposition with liberation of ammonia and of carbon dioxide.

Ammonium nitrate, NH 4 NO 3, is prepared by neutralizing nitric acid with ammonia, or ammonium carbonate, or by double decomposition between potassium nitrate and ammonium sulphate.

Ammonium nitrite, NH 4 NO 2, is formed by oxidizing ammonia with ozone or hydrogen peroxide; by precipitating barium or lead nitrites with ammonium sulphate, or silver nitrite with ammonium chloride.

The normal phosphate, (NH4)3P04,is obtained as a crystalline powder, on mixing concentrated solutions of ammonia and phosphoric acid, or on the addition of excess of ammonia to the acid phosphate (NH 4) 2 HPO 4.

It is soluble in water, and the aqueous solution on boiling loses ammonia and the acid phosphate NH 4 H 2 PO 4 is formed.

Diammonium hydrogen phosphate, (NH 4) 2 HPO 4, is formed by evaporating a solution of phosphoric acid with excess of ammonia.

The aqueous solution on boiling loses some ammonia and forms an acid sulphate.

Compounds are known which may be looked upon as derived from ammonia by the replacement of its hydrogen by the sulpho-group (HS0 3); thus potassium ammon-trisulphonate,N(SO 3 K) 3.2H20,is obtained as a crystalline precipitate on the addition of excess of potassium sulphite to a solution of potassium nitrite, KN02+3K2S03+2H20=N(S03K) 3 +4KHO.

The disulphonate is more readily obtained by moistening the nitrilosulphonate with dilute sulphuric acid and letting it stand for twenty-four hours, after which it is recrystallized from dilute ammonia.

Ammonia and ammonium salts can be readily detected, in very minute traces, by the addition of Nessler's solution, which gives a distinct yellow coloration in the presence of the least trace of ammonia or ammonium salts.

Larger quantities can be detected by warming the salts with a caustic alkali or with quicklime, when the characteristic smell of ammonia will be at once apparent.

The amount of ammonia in ammonium salts can be estimated quantitatively by distillation of the salts with sodium or potassium hydroxide, the ammonia evolved being absorbed in a known volume of standard sulphuric acid and the excess of acid then determined volumetrically; or the ammonia may be absorbed in hydrochloric acid and the ammonium chloride so formed precipitated as ammonium chlorplatinate, (NH4)2PtC16.

Hasselquist, who had travelled in that country as a 1 Some derive the name sal ammoniac from Jupiter Ammon, near whose temple it is alleged to have been found; others, from a district of Cyrenaica called Ammonia.

Dr Thomson first pointed out a process by synthesis, which has the advantage of being very simple, and at the same time rigidly accurate, resulting from his observation that when hydrochloric acid gas and ammonia gas are brought in contact with each other, they always combine in equal volumes.

It is now obtained from the ammoniacal liquor of gas works by distilling the liquor with milk of lime and passing the ammonia so obtained into hydrochloric acid.

Sodium trioxide, Na 2 O 31 is said to be formed from an excess of oxygen and a solution of sodammonium in liquid ammonia.

It unites directly with ammonia gas to form ammonium carbamate, NH 2 00ONH 4.

Paraquinones also combine with ammonia and with amines yielding amino-derivatives and hydroquinones.

When the oxide-free metal is heated gently in dry ammonia it is gradually transformed into a blue liquid, which on cooling freezes into a yellowish-brown or flesh-coloured solid, potassamide, KNH 2.

When heated to redness the amide is decomposed into ammonia and potassium nitride, NK 3, which is an almost black solid.

Potassamide, NH 2 K, discovered by Gay-Lussac and Thenard in 1871, is obtained as an olive green or brown mass by gently heating the metal in ammonia gas, or as a white, waxy, crystalline mass when the metal is heated in a silver boat.

It decomposes in moist air, or with water, giving caustic potash and ammonia, in the latter case with considerable evolution of heat.

The soluble iodides, on the addition of silver nitrate to their nitric acid solution, give a yellow precipitate of silver iodide, which is insoluble in ammonia solution.

More successful results are obtained by the use of ammonia.

Ammonia should be given by inhalation, and artificial respiration must never be forgotten, as by it the paralysed breathing may be compensated for and the poison excreted.

Normal chromates on the addition of silver nitrate give a red precipitate of silver chromate, easily soluble in ammonia, and with barium chloride a yellow precipitate of barium chromate, insoluble in acetic acid.

Chromium in the form of its salts may be estimated quantitatively by precipitation from boiling solutions with a slight excess of ammonia, and boiling until the free ammonia is nearly all expelled.

Gaseous ammonia passed over the oxide reduces it to the sesquioxide with formation of nitrogen and water.

It dissolves iodine and absorbs chlorine, and is decomposed by water with formation of chromic and hydrochloric acids; it takes fire in contact with sulphur, ammonia, alcohol, &c., and explodes in contact with phosphorus; it also acts as a powerful oxidizing agent.

By suspending it in ether and passing ammonia, potassium amidochromate, Cr02-NH2.

By passing ammonia over heated chromic chloride, the nitride, CrN, is formed as a brownish powder.

Chromium salts readily combine with ammonia to form complex salts in which the ammonia molecule is in direct combination with the chromium atom.

It will be advantageous if the spectra of ammonia, benzene, aniline and dimethyl aniline be compared, when the re-' markable coincidences will at once become apparent, as also the different weighting of the molecule.

By the reduction of ortho-nitrobenzaldehyde with ferrous sulphate and ammonia, ortho-aminobenzaldehyde is obtained.

It is prepared by adding sodium phosphate to magnesium sulphate in the presence of ammonia and ammonium chloride.

Water decomposes it with liberation of ammonia and formation of magnesium hydroxide.

The magnesium salts may be detected by the white precipitate formed by adding sodium phosphate (in the presence of ammonia and ammonium chloride) to their solutions.

This relation does not hold for very soluble gases, such as ammonia, at low temperatures.

Certain solvents, such as water, liquid ammonia or liquid hydrocyanic acid, possess the power of making some solutes, such as mineral salts and acids, when dissolved in them, conductors of electricity.

Beyond variable quantities of moisture and traces of carbonic acid, hydrogen, ammonia, &c., the only constituents recognized were nitrogen and oxygen.

Under the influence of the heat the atmospheric oxygen unites with the hydrogen of the ammonia, and when the excess of the latter is removed with sulphuric acid, the gas properly desiccated should be pure nitrogen, derived in part from the ammonia, but principally from the air.

A few concordant determinations of density having been effected, the question was at first regarded as disposed of, until the thought occurred that it might be desirable to try also the more usual method of preparation in which the oxygen is removed by actual oxidation of copper without the aid of ammonia.

Subsequently when oxygen was substituted for air in the first method, so that all (instead of about one-seventh part) of the nitrogen was derived from ammonia, the difference rose to 2%.

Whatever were the means employed to rid air of accompanying oxygen, a uniform value of the density was arrived at, and this value was z% greater than that appertaining to nitrogen extracted from compounds such as nitrous oxide, ammonia and ammonium nitrite.

He proceeds to give what has been quoted as his first table of atomic weights, but on p. 248 of his laboratory notebooks for 1802-1804, under the date 6th of September 1803, there is an earlier one in which he sets forth the relative weights of the ultimate atoms of a number of substances, derived from analysis of water, ammonia, carbon-dioxide, &c. by chemists of the time.

Aluminium hydrate, Al(OH) 3, is obtained as a gelatinous white precipitate, soluble in potassium or sodium hydrate, but insoluble in ammonium chloride, by adding ammonia to a cold solution of an aluminium salt; from boiling solutions the precipitate is opaque.

The chief point to be borne in mind in making these mixtures is not to combine in the same compost any bodies that are antagonistic in their nature, as for example lime and ammonia.

It should not be allowed to lie too long unmoved when fresh, as it will then heat violently, and the ammonia is thus driven off.

Quicklime should not be used, as it dispels the greater part of the ammonia.

The urine should be allowed to putrefy, as in its decomposition a large amount of ammonia is formed, which should then be fixed by sulphuric acid or gypsum; or it may be applied to the growing crops after being freely diluted with water or absorbed in a compost heap. Liquid manures can be readily made from most of the solid manures when required, simply by admixture with water.

It is largely supplied in all the most fertilizing of organic manures, but when required in the inorganic state must be obtained from some of the salts of ammonia, as the sulphate, the muriate or the phosphate, all of which, being extremely energetic, require to be used with great caution.

These salts of ammonia may be used at the rate of from 2 to 3 cwt.

The most commonly used nitrogenous manures are nitrate of soda, nitrate of potash and sulphate of ammonia, the prices of which are constantly fluctuating.

It is also employed in the case of liquid manures to fix the ammonia.

Soot forms a good top-dressing; it consists principally of charcoal, but contains ammonia and a smaller proportion of phosphates and potash, whence its value as a manure is derived.

Liebig, Ann., 1832, r, p. 199), by heating chloral with alkalis (Liebig), CC1 3 CHO + NaHO = CHC1 3 + NaHCO 2, or by heating trichloracetic acid with ammonia (J.

The -y-diketones are characterized by the readiness with which they yield furfurane, pyrrol and thiophene derivatives, the furfurane derivatives being formed by heating the ketones with a dehydrating agent, the thiophenes, by heating with phosphorus pentasulphide, and the pyrrols by the action of alcoholic ammonia or amines.

The 1 5 diketones of this type, when heated with aqueous ammonia, form pyridine derivatives.

The hydroxyl group is more reactive than in the phenols, the naphthols being converted into naphthylamines by the action of ammonia, and forming ethers and esters much more readily.

On reduction it yields ammonia and glycocoll (aminoacetic acid).

Hydrogen is a very powerful reducing agent; the gas occluded by palladium being very active in this respect, readily reducing ferric salts to ferrous salts, nitrates to nitrites and ammonia, chlorates to chlorides, &c.

When heated with ammonia, they yield acid amides.

They are monacid bases, which are not very stable; they readily take up the elements of water (when boiled with acids or alkalies), yielding amides and ammonia.

On dry distillation they yield nitriles and ammonia.

This process is repeated several times, and the final precipitate is dissolved in hydrochloric acid and precipitated by ammonia, washed and dried.

Beryllium is estimated quantitatively by precipitation with ammonia, and ignition to oxide.

Besides having a considerable share in the commerce of the port of New York, Bayonne is an important manufacturing centre; among its manufactures are refined petroleum, refined copper and nickel (not from the ore), refined borax, foundry and machine-shop products, tubular boilers, electric launches and electric motors, chemicals (including ammonia and sulphuric and nitric acids), iron and brass products, wire cables and silk goods.

In either case the two hydrocarbons are finally separated by fractional crystallization of their picrates, which are then decomposed by ammonia.

When heated above its melting-point, it yields ammonia, cyanuric acid, biuret and ammelide.

Dry chlorine gas passed into melted urea decomposes it with formation of cyanuric acid and ammonium chloride, nitrogen and ammonia being simultaneously liberated.

It is also decomposed by warm aqueous solutions of caustic alkalis, with evolution of ammonia and carbon dioxide.

In this reaction urea is heated in a dry tube until it gives off ammonia freely; the residue is dissolved in water, made alkaline with caustic soda, and a drop of copper sulphate solution is added, when a fine violet-red coloration is produced.

When heated with water it is decomposed into carbon dioxide, ammonia, methylamine and acetic acid.

They are readily decomposed by alkalis, yielding cyanuric acid and ammonia.

When heated strongly it is decomposed into ammonia and cyanuric acid.

Baryta water hydrolyses it to carbon dioxide, ammonia and urea.

It is hydrolysed by alkalis, giving carbon dioxide, ammonia and sulphuretted hydrogen.

Benzamide, C 6 H 5 CONH 2, is prepared by the action of benzoyl chloride on ammonia or ammonium carbonate, or from ethyl benzoate and ammonia.

In the presence of ammonium salts the precipitate is dirt y white in colour, whilst in the presence of free ammonia it is a buff colour.

Manganese may be estimated quantitatively by precipitation as carbonate, this salt being then converted into the oxide, Mn 3 0 4 by ignition; or by precipitation as hydrated dioxide by means of ammonia and bromine water, followed by ignition to NIn 3 0 4.

This amidoguanidine decomposes on hydrolysis with the formation of semicarbazide, NH 2 CO NH NH 21 which, in its turn, breaks down into carbon dioxide, ammonia and hydrazine.

Moreover, the ammonia process has been gradually elaborated into a very complicated but perfectly regularly working scheme, in which the cost of labour and the loss of ammonia are reduced to a minimum.

It begins, however, not with ready-made ammonium bicarbonate, but with the substances from which it is formed - ammonia, water and carbon dioxide - which are made to act on sodium chloride.

These vessels, as well as all others which are used in the process, are not open to the air, but communicate with it through washers in which fresh salt solution is employed for retaining any escaping vapours of ammonia.

This is a tall iron erection, built up from superposed cylinders, which are separated from one another by perforated horizontal diaphragms, con this recovery is carried out in the most efficient manner, the process cannot possibly pay; but so much progress has been made in this direction that the loss of ammonia is very slight indeed, merely a fraction per cent.

The ammonia is for the major part found in the mother-liquor as ammonium chloride.

The solution of calcium chloride is run to waste, the ammonia is re-introduced into the process.

The steam causes the action of the lime on the ammonium chloride to take place in this lower portion of the still, from which the steam, mixed with all the liberated ammonia, rises into the upper portion of the column where its heat serves to drive out the volatile ammonium carbonate.

Just below the top there is a cooling arrangement, so that nearly all the water is condensed and runs back into the column, while the ammonia, with the carbon dioxide formerly combined with part of it, passes on first through an outside cooler where the remaining water is condensed, and afterwards into the vessels, already described, where the ammonia is absorbed by a solution of salt and thus again introduced into the process.

The reversible character of the principal reaction has the consequence that a considerable portion of the sodium chloride (up to 33%) is lost, being contained in the waste calcium chloride solution which issues from the ammonia stills.

It is readily soluble in acids and in an aqueous solution of ammonia.

Ammonium hydroxide gives a green precipitate of the hydroxide, soluble in excess of ammonia, forming a blue solution.

It forms crystalline compounds with ammonia and the organic bases.

Chalcopyrite is decomposed by nitric acid with separation of sulphur and formation of a green solution; ammonia added in excess to this solution changes the green colour to deep blue and precipitates red ferric hydroxide.

On boiling gelatinous silica with ammonium polytungstate and evaporating with the occasional addition of ammonia, ammonium silicodecitungstate is obtained as short rhombic prisms. On adding silver nitrate and decomposing the precipitated silver salt with hydrochloric acid, a solution is obtained which on evaporation in a vacuum gives the free acid as a glassy mass.

It is sparingly soluble in cold water, but is easily dissolved by potassium carbonate or ammonia.

A nitride, W2N3, is obtained as a black powder by acting with ammonia on the oxytetrachloride or hexachloride; it is insoluble in sodium hydroxide, nitric and dilute sulphuric acids; strong sulphuric acid, however, gives ammonia and tungstic acids.

Ammonia does not react with tungsten or the dioxide, but with trioxide at a red heat a substance of the formula W 5 H 6 N 3 0 5 is obtained, which is insoluble in acids and alkalis and on ignition decomposes, evolving nitrogen, hydrogen and ammonia.

His method consisted in using magnesia instead of lime for the recovery of the ammonia (which occurs in the form of ammonium chloride in the ammonia-soda process), and then by evaporating the magnesium chloride solution and heating the residue in steam, to condense the acid vapours and so obtain hydrochloric acid.

Heated in a current of ammonia it gives succinimide, which is also obtained on heating acid ammonium succinate.

It dissolves in ammonia, forming a colourless solution which rapidly oxidizes and turns blue.

Both the oxide and hydroxide dissolve in ammonia to form a beautiful azure-blue solution (Schweizer's reagent), which dissolves cellulose, or perhaps, holds it in suspension as water does starch; accordingly, the solution rapidly perforates paper or calico.

Its solution in ammonia is at first colourless, but rapidly turns blue, owing to oxidation.

It absorbs ammonia, forming the compound Cu 2 I 2r 4NH 3.

Ammonia gives a characteristic blue coloration when added to a solution of a copper salt; potassium ferrocyanide gives a brown precipitate, and, if the solution be very dilute, a brown colour is produced.

Investigation of the cyanic ethers (1848) yielded a class of substances which opened out a new field in organic chemistry, for, by treating those ethers with caustic potash, he obtained methylamine, the simplest organic derivative of ammonia (1849), and later (1851) the compound ureas.

Silver picrate and methyl iodide yield the methyl ester, which gives with ammonia picramide.

Guntz (Comptes rendus, 1901, 133, p. 872) electrolyses a saturated solution of barium chloride using a mercury cathode and obtains a 3% barium amalgam; this amalgam is transferred to an iron boat in a wide porcelain tube and the tube slowly heated electrically, a good yield of pure barium being obtained at about looo C. The metal when freshly cut possesses a silver white lustre, is a little harder than lead, and is extremely easily oxidized on exposure; it is soluble in liquid ammonia, and readily attacks both water and alcohol.

Thus carbolic acid or carbolized ammonia are sniffed into the nose to destroy the microbes there, or the nose is washed out by an antiseptic solution as a nasal douche; bismuth or morphine are insufflated, or zinc ointment is applied, to cover the mucous membrane, and protect it from further irritation; and various antiseptic gargles, paints and powders applied to the pharynx in order to prevent the microbic inflammation from extending to the pharynx and down the trachea and bronchi, for many a severe bronchitis begins first by sneezing and nasal irritation.

Two very old remedies for fever are acetate of ammonia and nitrous ether.

Now we can see the reason for their administration, because the nitrous ether, consisting chiefly of ethyl nitrite, dilates the superficial vessels and thus allows greater escape of heat from the surface; while acetate of ammonia, by acting as a diaphoretic and stimulating the secretion of sweat, increases the loss of heat by evaporation.

Among the substances of which he investigated the composition were ammonia, sulphuretted hydrogen and prussic acid, and his experiments on chlorine, which he regarded, not as an element, but as oxygenated muriatic (oxymuriatic) acid, led him to propose it as a bleaching agent in 1785.

In effect the urea first becomes carbonate of ammonia by a simple hydrolysis brought about by bacteria, more and more definitely known since Pasteur, van Tieghem and Cohn first described them.

Many forms in rivers, soil, manure heaps, &c., are capable of bringing about this change to ammonium carbonate, and much of the loss of volatile ammonia on farms is preventible if the facts are apprehended.

It had long been known that under certain conditions large quantities of nitrate (saltpetre) are formed on exposed heaps of manure, &c., and it was supposed that direct oxidation of the ammonia, facilitated by the presence of porous bodies, brought this to pass.

In other words these bacteria can build up organic matter from purely mineral sources by assimilating carbon from carbon dioxide in the dark and by obtaining their nitrogen from ammonia.

When the latter have oxidized ammonia to nitrite, however, the former step in and oxidize it still further to nitric acid.

In addition to the bacterial actions which result in the oxidization of ammonia to nitrous acid, and of the latter to nitric acid, the reversal of such processes is also brought about by numerous bacteria in the soil, rivers, &c. Warington showed some time ago that many species are able to reduce nitrates to nitrites, and such reduction is now known to occur very widely in nature.

The researches of Gayon and Dupetit, Giltay and Aberson and others have shown, moreover, that bacteria exist which carry such reduction still further, so that ammonia or even free nitrogen may escape.

Fresh manure abounds in de-nitrifying bacteria, and these organisms not only reduce the nitrates to nitrites, even setting free nitrogen and ammonia, but their effect extends to the undoing of the work of what nitrifying bacteria may be present also, with great loss.

The combined nitrogen of dead organisms, broken down to ammonia by putrefactive bacteria, the ammonia of urea and the results of the fixation of free nitrogen, together with traces of nitrogen salts due to meteoric activity, are thus seen to undergo various vicissitudes in the soil, rivers and surface of the globe generally.

The ammonia may be oxidized to nitrites and nitrates, and then pass into the higher plants and be worked up into proteids, and so be handed on to animals, eventually to be broken down by bacterial action again to ammonia; or the nitrates may be degraded to nitrites and even to free nitrogen or ammonia, which escapes.

He studied the formation of aldehyde from alcohol by various methods, also obtaining its crystalline compound with ammonia, and he was the discoverer of furfurol.

It is then heated with a mixture of ammonium chloride and ammonia, filtered and washed with a hot dilute solution of the same mixture.

To the filtrate (or, if no silver is present, to the diluted nitric acid solution) io cc. of ammonia are added, and a standard solution of potassium cyanide is run in from a burette until the blue colour has nearly disappeared.

The potassium cyanide solution is standardized by dissolving 0.5 gramme o£ pure copper in 5 cc. of nitric acid, diluting, adding io cc. of ammonia, and titrating exactly as described above.

The solution is cooled, 50 cc. water added, then 5 cc. ammonia, and the solution is boiled for five minutes.

A few drops of starch solution are then added, and when the blue colour has nearly vanished a drop or two of methyl orange makes the end reaction very sharp. The thiosulphate solution is standardized by dissolving o 3 to o 5 gramme of pure copper in 3 cc. of nitric acid, adding 50 cc. of water and 5 cc. of ammonia, and titrating as above after the addition of 5 cc. of glacial acetic acid and 5 cc. of the potassium iodide solution.

Tannic acid, for instance, precipitates codeine as a tannate, salts of many of the heavy metals form precipitates of meconates and sulphates, whilst the various alkalis, alkaline carbonates and ammonia precipitate the important alkaloids.

With ammonia it reacts to form di- and triacetoneamines.

The fused mass is dissolved in dilute ammonia and diluted to about fifty times the weight of the silver it contains.

It dissolves in ammonia with the liberation of nitrogen and the formation of silver oxide, Ag 2 O; and in sulphuric acid forming a fairly stable dark green liquid which, on dilution, gives off oxygen and forms silver sulphate.

It readily dissolves in ammonia, the solution, on evaporation, yielding rhombic crystals of 2AgC1.3NH 3; it also dissolves in sodium thiosulphate and potassium cyanide solutions.

It is very slightly soluble in nitric acid, and less soluble in ammonia than the chloride.

It combines with ammonia to form the readily soluble 2NH 3 Ag 2 SO 4.

Fulminating silver is an extremely explosive black powder, first obtained in 1788 by Berthelot, who acted with ammonia on silver oxide (prepared by adding lime water to a silver solution).

Ruhemann prepared y-substituted dioxypyridines by condensing alkyl-dicarboxy-glutaconic esters with ammonia.

It is decomposed by hydriodic acid with liberation of selenium and iodine, and by ammonia with formation of selenium and nitrogen.

It is, however, very soluble in excess of ammonia.

When a solution of chlorine is first added and then ammonia an emerald green colour, due to the formation of thalleoquin, is developed.

Its value in the early stages of a bronchitis or tracheitis is due to the ammonia.

Silver nitrate in the presence of nitric acid gives with bromides a pale yellow precipitate of silver bromide, AgBr, which is sparingly soluble in ammonia.

Just as the amines are derived from ammonia, so from phosphine are derived the primary, secondary and tertiary organic phosphines by the exchange of hydrogen for alkyl groups, and corresponding to the phosphonium salts there exists a series of organic phosphonium bases.

Ammonia also reacts immediately, giving phosphorus diamide, P(OH)(NH2)2, and the corresponding ammonium salt.

With dry ammonia it gives ammonium fluoride and a compound P(NH2)2SF.

Nitrogen Compounds.-Phosphorus pentachloride combines directly with ammonia, and the compound when heated to redness loses ammonium chloride and hydrochloric acid and gives phospham, PN 2 H 4, a substance first described by Davy in 1811.

It is a white, infusible, very stable solid, which decomposes water on heating, giving ammonia and metaphosphoric acid, whilst alkalis give an analogous reaction.

The diamide, PO (NH 2) (NH), results when the pentachloride is saturated with ammonia gas and the first formed chlorophosphamide, PC1 3 (NH 2) 2, is decomposed by water.

The alkaloid is a strong base and is very readily oxidized; chromic acid converts it into normal butyric acid and ammonia; hydrogen peroxide gives aminopropylvalerylaldehyde, NH 2 CH(C 3 11 7) (CH2)3 CHO, whilst the benzoyl derivative is oxidized by potassium permanganate to benzoyl-a-aminovaleric acid, C 6 H 5 CO NH CH(C 3 H 7) (CH 2)3 COOH.

It forms small hard prisms which become red on exposure to air containing ammonia, owing to the formation of murexide (ammonium purpurate),C $ 11 4 (NH 4)N 5 0 6.

The formation of murexide is used as a test for the presence of uric acid, which on evaporation with dilute nitric acid gives alloxantin, and by the addition of ammonia to the residue the purple red colour of murexide becomes apparent.

The temperature must be above 18'; and the absorption is prevented by ammonia, olefines, alcohol, and some other substances.

Carbon monoxide is absorbed by a solution of cuprous chloride in hydrochloric acid or, better, in ammonia.

Gases soluble in water, such as ammonia, hydrochloric acid, sulphuretted hydrogen, sulphur dioxide, &c., are estimated by passing a known volume of the gas through water and titrating the solution with a standard solution.

The ammonia is derived from the nitrogen present in the coal combining with hydrogen during destructive distillation, the nitrogen becoming distributed amongst all three classes of products.

The following table will give an approximate idea of the proportions which go to each Nitrogen as ammonia cyanogen in gas and combined in tar in coke .

The second liquid product of the destructive distillation of coal is the ammoniacal or gas liquor, which consists of water containing ammonia salts in solution, partly condensed from the hot gas, and partly added to wash the gas in the scrubbers.

It contains, as its principal constituents, ammonia, partly combined with carbonic acid and sulphuretted hydrogen to form compounds which are decomposed on boiling, with evolution of ammonia gas, and partly combined with stronger acids to form compounds which require to be acted upon by a strong alkali before the ammonia contained in them can be liberated.

The ammonia in the first class of compounds is technically spoken of as "free"; that present in the latter as "fixed."

The most soluble of the constituents of crude coal gas is ammonia, 780 volumes of which are soluble in one volume of water at normal temperature and pressure, and the water in the hydraulic main absorbs a considerable quantity of this compound from the gas and helps to form the ammoniacal liquor, whilst, although the liquor is well agitated by the gas bubbling through it, a partial separation of tar from liquor is effected by gravitation.

At this point in the manufacturing process the gas has already undergone some important changes in its composition, but there yet remain impurities which must be removed, these being ammonia, sulphuretted hydrogen, carbon disulphide and carbon dioxide.

Ammonia is of considerable marketable value, and even in places where the local Gas Act does not prescribe that it shall be removed, it is extracted.

Atkinson Butterfield gives the composition of the gas at this It happens that ammonia, being a strong base, will effect the extraction of a certain proportion of such compounds as sulphuretted hydrogen, carbon dioxide and hydrocyanic acid, and the gas is now washed with water and ammoniacal liquor.

The final washing for ammonia is effected in an apparatus termed a" scrubber,"which is a cylindrical tower packed with boards 4 in, thick by II in.

In this wet purifying apparatus the gas is almost wholly freed from ammonia and from part of the sulphuretted hydrogen, whilst carbon dioxide and carbon disulphide are also partially extracted.

The most important of these is sulphate of ammonia, which is used for agricultural purposes as a manure, and is obtained by passing ammonia into sulphuric acid and crystallizing out the ammonium sulphate produced.

To do this, saturated ammoniacal liquor is decomposed by lime in the presence of steam, and the freed ammonia is passed into strong sulphuric acid, the saturated solution of ammonium sulphate being carefully crystallized.

The spray of water removes the dust and part of the tar and ammonia from the gases, much steam being produced at the same time.

This water is withdrawn from time to time and worked for the ammonia it contains.

This liquid is a strong solution of ammonium sulphate, containing about 2 5% free sulphuric acid which absorbs nearly all the ammonia from the gases, without dissolving much of the tarry substances.

It absorbs ammonia gas, forming the compound FeC12.6NH31 which on heating loses ammonia, and, finally, yields ammonium chloride, nitrogen and iron nitride.

Ferri hydroxidum (U.S.P.), the hydrated oxide of iron, made by precipitating ferric sulphate with ammonia, is used solely as an antidote in arsenical poisoning.

It deliquesces and oxidizes on exposure, inflames in dry chlorine and is reduced to ammonia by zinc dust.

This is recrystallized and roasted to vanadium pentoxide, which is then suspended in water into which ammonia is passed, when ammonium metavanadate is again formed and may be purified by recrystallization.