Salts in A Sentence

    1

    A blue coloration indicates nitrogen, and is due to the formation of potassium (or sodium) cyanide during the fusion, and subsequent interaction with the iron salts.

    2

    A freedom of interchange is thus indicated between the opposite parts of the molecules of salts in solution, and it follows reasonably that with the solution of a single salt, say sodium chloride, continual interchanges go on between the sodium and chlorine parts of the different molecules.

    3

    A large number of cobalt compounds are known, of which the empirical composition represents them as salts of cobalt to which one or more molecules of ammonia have been added.

    4

    A.horizontal shaft runs length-ways through the trough, and is provided with stirring blades, arranged in such a manner that they constantly scrape the bottom, so that the salts cannot burn fast upon it, and are at the same time moved forward towards one of the ends of the trough where they are automatically removed by means of a chain of buckets.

    5

    Aconitine (C33H45N013, according to Dunstan; C34H47NOH, according to Freund) is a crystalline base, soluble in alcohol, but very sparingly in water; its alcoholic solution is dextrorotatory, but its salts are laevorotatory.

    6

    After long continued frost the last of the included brine may be frozen and the salts driven out in crystals on the surface; these crystals are known to polar explorers by the Siberian name of rassol.

    7

    After the vigorous reaction has ceased and all the sodium has been used up, the mass is thrown into dilute hydrochloric acid, when the soluble sodium salts go into solution, and the insoluble boron remains as a brown powder, which may by filtered off and dried.

    8

    Again, the diazonium chlorides combine with platinic chloride to form difficultly soluble double platinum salts, such as (C 6 H 5 N 2 C1) 2 PtC1 4; similar gold salts, C 6 H,N 2 C1 AuC1 3, are known.

    9

    Alkaline carbonates give precipitates of basic carbonates, the formation of which is also retarded by the presence of ammonium salts.

    10

    Alkylated amino-azo-benzenes are also known, and are formed by the coupling of diazonium salts with alkylated amines, provided they contain a free para.

    11

    All copper salts in dilute solution are blue, which is therefore the colour of the copper ion.

    12

    All potassium salts if taken in large doses are cardiac depressants, they also depress the nervous system, especially the brain and spinal cord.

    13

    All these salts are mild astringents when applied externally, as they coagulate the albumen of the tissues and of any discharge which may be present.

    14

    Allophanic acid, NH 2 C0 NH CO 2 H, is not known in the free state, as when liberated from its salts, it is decomposed into urea and carbon dioxide.

    15

    Also (d +1) mannonic acid can be split into the d and 1 acids by fractional crystallization of the strychnine or brucine salts.

    16

    Although the acid is monobasic, salts of polymeric forms exist of the types (MP0 3) n, where n may be 1, 2, 3, 4, 6.

    17

    Although the salts have been grouped in the above 1 Comptes rendus, Acad.

    18

    Aluminium forms one series of salts, derived from the trioxide, Al 2 0 3.

    19

    Amidoguanidine is a body of hydrazine type, for it reduces gold and silver salts and yields a benzylidine derivative.

    20

    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.

    21

    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.

    22

    Ammonia, recognizable by its odour and alkaline reaction, indicates ammoniacal salts or cyanides containing water.

    23

    Ammonium chloride has a different action and therapeutic use from the rest of the ammonium salts.

    24

    Ammonium salts too are found distributed through all fertile soil, in sea-water, and in most plant and animal liquids, and also in urine.

    25

    Among the principal varieties are those which contain carbolic acid and other ingredients of coal tar, salicylic acid, petroleum, borax, camphor, iodine, mercurial salts, sulphur and tannin.

    26

    An acid (q.v.) is a compound of hydrogen, which element can be replaced by metals, the hydrogen being liberated, giving substances named salts.

    27

    An alkali or base is a substance which neutralizes an acid with the production of salts but with no evolution of hydrogen.

    28

    An important distinction separates true mixed crystals and crystallized double salts, for in the latter the properties are not linear functions of the properties of the components; generally there is a contraction in /10.591 volume, while the re fractive indices and other physical properties do not, in general, obey the additive law.

    29

    An important experiment by C. Gunther 2 seems however to show that the radiation of metallic salts in a flame has an intensity equal to that belonging to it in virtue of its temperature.

    30

    Annexed are values of Io 6 K for the different salts examined, w being the weight of the salt per c.c. of the solution.

    31

    Another defect arising during curing and fermentation is the efflorescence of salts on the surface, a phenomenon known as " saltpetre "; light brushing and spraying with a weak solution of acetic acid are effective remedies.

    32

    Another mode of separating the two acids is to convert them into calcium salts, which are then treated with a perfectly neutral solution of cupric chloride, soluble cupric citrate and calcium chloride being formed, while cupric tartrate remains undissolved.

    33

    Applied externally lead salts have practically no action upon the unbroken skin, but applied to sores, ulcers or any exposed mucous membranes they coagulate the albumen in the tissues themselves and contract the small vessels.

    34

    Aromatic Amines.-The aromatic amines in some respects resemble the aliphatic amines, since they form salts with acids, and double salts with platinum chloride, and they also distil without decomposition.

    35

    As a rule the soluble salts if taken in sufficient quantities produce acute poisoning, and the insoluble salts chronic plumbism.

    36

    As alum and green vitriol were applied to a variety of substances in common, and as both are distinguished by a sweetish and astringent taste, writers, even after the discovery of alum, do not seem to have discriminated the two salts accurately from each other.

    37

    As Marcet had foreshadowed from the analysis of 14 samples in 1819, the larger series of exact analyses proved that the variations in the proportion of individual salts to the total salts are very small, and all analyses since Dittmar's have confirmed this result.

    38

    As sea-water contains both sulphates and magnesium salts, it is especially necessary in concrete for harbour work to take every care to produce an impervious structure.

    39

    At about the same time Boyle investigated several acids; he established their general reddening of litmus, their solvent power of metals and basic substances, and the production of neutral bodies, or salts, with alkalies.

    40

    At the same time any lead, calcium, barium and strontium present are precipitated as sulphates; it is therefore advantageous to remove these metals by the preliminary addition of sulphuric acid, which also serves to keep any basic iron salts in solution.

    41

    Auric cyanide, Au(CN) 3, is not certainly known; its double salts, however, have been frequently described.

    42

    Bamberger (Ber., 18 94, 27, p. 9 1 4) obtained the diazoic acids, R NH NO 2, substances which he had previously prepared by similarly oxidizing the diazonium salts, by dehydrating the nitrates of primary amines with acetic anhydride, and by the action of nitric anhydride on the primary amines.

    43

    Being a tetrabasic acid it can form four classes of salts; for example, the four solium salts Na 4 P 2 0 7, Na3HP207, Na 2 H 2 P 2 0 7, NaH 3 P 2 0 7 are known.

    44

    Benzene diazonium hydroxide, although a strong base, reacts with the alkaline hydroxides to form salts with the evolution of heat, and generally behaves as a weak acid.

    45

    Beryllium salts are easily soluble and mostly have a sweetish taste (hence the name Glucinum, from yXv,dc, sweet); they are readily precipitated by alkaline sulphides with formation of the white hydroxide, and may be distinguished from salts of all other metals by the solubility of the oxide in ammonium carbonate.

    46

    Berzelius's investigation of the action of the electric current on salts clearly demonstrated the invaluable assistance that electrolysis could render to the isolator of elements; and the adoption of this method by Sir Humphry Davy for the analysis of the hydrates of the metals of the alkalis and alkaline earths, and the results which he thus achieved, established its potency.

    47

    Beside the ordinary acid and neutral salts, a series of salts called quadroxalates is known, these being salts containing one molecule of acid salt, in combination with one molecule of acid, one of the most common being "salt of sorrel," KHC 2 0 4.

    48

    Besides liquor sodii ethylatis the following salts and preparations are used in the British Pharmacopoeia.

    49

    Besides the rock-salt, which is excavated by blasting, the saline deposits of Stassfurt yield a considerable quantity of deliquescent salts and other saline products, which have encouraged the foundation of numerous chemical factories in the town and in the neighbouring village of Leopoldshall, which lies in Anhalt territory.

    50

    Blagden (Ber.,1900,33,p.2544), who consider that three simultaneous reactions occur, namely, the formation of labile double salts which decompose in such a fashion that the radical attached to the copper atom wanders to the aromatic nucleus; a catalytic action, in which nitrogen is eliminated and the acid radical attaches itself to the aromatic nucleus; and finally, the formation of azo compounds.

    51

    Both animals and plants take their water and inorganic salts directly as such.

    52

    Both in the gum and in the boiled-off state silk has the peculiar property of imbibing certain metallic salts largely and combining very firmly with them, the fibre remaining to external appearance undiminished in strength and lustre, but much added to in size and weight.

    53

    Bunsen, the best source of rubidium and caesium salts is the residue left after extraction of lithium salts from lepidolite.

    54

    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).

    55

    But when we pass to solutions of mineral salts and acids - to solutions of electrolytes in fact - we find that the observed values of the osmotic pressures and of the allied phenomena are greater than the normal values.

    56

    Butter and cheese salts are not stove-dried, but left in their more or less moist condition, as being thus more easily applied to their respective uses.

    57

    By heating the nitrate it is obtained as hemimorphous pyramids belonging to the hexagonal system; and by heating the chloride in a current of steam as hexagonal prisms. It is insoluble in water; it dissolves readily in all aqueous acids, with formation of salts.

    58

    By suspending the precipitated cerous hydroxide in water and passing chlorine through the solution, a hydrated form of the dioxide, 2CeO 2.3H 2 O, is obtained, which is readily soluble in nitric and sulphuric acids, forming ceric salts, and in hydrochloric acid, where it forms cerous chloride, with liberation of chlorine.

    59

    By the addition of caustic soda to cerous salts, a white precipitate of cerous hydroxide is formed.

    60

    By the addition of potassium bromide and bromine water to diazonium salts they are converted into a perbromide, e.g.

    61

    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.

    62

    By the addition of the diazonium salts to a hot concentrated solution of a caustic alkali, C. Schraube and C. Schmidt(Ber., 18 94, 2 7, p. 520)obtained an isomer of potassium benzene diazotate.

    63

    Cadmium salts can be recognized by the brown incrustation which is formed when they are heated on charcoal in the oxidizing flame of the blowpipe; and also by the yellow precipitate formed when sulphuretted hydrogen is passed though their acidified solutions.

    64

    Cadmium sulphide, CdS, occurs naturally as greenockite (q.v.), and can be artificially prepared by passing sulphuretted hydrogen through acid solutions of soluble cadmium salts, when it is precipitated as a pale yellow amorphous solid.

    65

    Carnelley and Williams employed certain salts of known melting point; whilst the Seger's cones, employed in porcelain manufacture, depend on the fusion of small cones made of clay.

    66

    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.

    67

    Characteristic, also, is their action on a photographic plate, and the phosphorescence which they occasion when they impinge on zinc sulphide and some other salts.

    68

    Chemically they resemble the albumins, being split up by acids or ferments into albumoses, peptones and amino-acids, forming salts, and giving N =C6 1 The pyrimidin ring is numbered 2C "C5.

    69

    Chromic acid and its salts, the chromates and bichromates, can be detected by the violet coloration which they give on addition of hydrogen peroxide to their dilute acid solution, or by the fact that on distillation with concentrated sulphuric acid and an alkaline chloride, the red vapours of chromium oxychloride are produced.

    70

    Chromic salts are of a blue or violet colour, and apparently the chloride and bromide exist in a green and violet form.

    71

    Chromium and its salts may be detected by the fact that they give a deep green bead when heated with borax, or that on fusion with sodium carbonate and nitre, a yellow mass of an alkaline chromate is obtained, which, on solution in water and acidification with acetic acid, gives a bright yellow precipitate on the addition of soluble lead salts.

    72

    Chromium forms three series of compounds, namely the chromous salts corresponding to CrO, chromous oxide, chromic salts, corresponding to Cr203, chromium sesquioxide, and the chromates corresponding to Cr0,, chromium trioxide or chromic anhydride.

    73

    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.

    74

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

    75

    Chromium sesquioxide is a basic oxide, although like alumina it acts as an acid-forming oxide towards strong bases, forming salts called chromites.

    76

    Chromous chloride, CrC1 2, is prepared by reducing chromic chloride in hydrogen; it forms white silky needles, which dissolve in water giving a deep blue solution, which rapidly absorbs oxygen, forming basic chromic salts, and acts as a very strong reducing agent.

    77

    Chrysaniline (diamino-phenylacridinei) forms red-coloured salts, which dye silk and wool a fine yellow; and the solutions of the salts are characterized by their fine yellowish-green fluorescence.

    78

    Citric acid, being tribasic, forms either acid monometallic, acid dimetallic or neutral trimetallic salts; thus, mono-, diand tri-potassium and sodium citrates are known.

    79

    Cl-OH, chlorochromic acid, is only known in the form of its salts, the chlorochromates.

    80

    Cobalt salts may be readily detected by the formation of the black sulphide, in alkaline solution, and by the blue colour they produce when fused with borax.

    81

    Corresponding to this acid, a series of salts, named chloraurates or aurichlorides, are known.

    82

    Dahms in the case of salts, could be measured in the lead-tin alloys.

    83

    Davy on the decomposition of the solutions of salts by the voltaic current were turned to account in the water voltameter telegraph of Sdmmering and the modification of it proposed by Schweigger, and in a similar method proposed by Coxe, in which a solution of salts was substituted for water.

    84

    Di-metallic salts are obtained by heating cyanates alone, e.g.

    85

    Double salts of cerous chloride with stannic chloride, mercuric chloride, and platinic chloride are also known.

    86

    Doubtless, the excess of any soluble mineral salt or salts interferes with the osmotic absorption of the roots; and although calcium carbonate is insoluble in pure water, it is slightly soluble in water containing carbon dioxide.

    87

    During the formation of the Schlier the plain was covered by an inland sea or series of salt lakes, in which evaporation led to the concentration and finally to the deposition of the salts contained in the water.

    88

    Epsom salts crystallizes in the orthorhombic system, being isomorphous with the corresponding zinc and nickel sulphates, and also with magnesium chromate.

    89

    Examples of the first case are found among the colourless acridines and quinoxalines which give coloured salts; of the second case we may notice the colourless hydrochloride and sulphate of the deep yellow o-aminobenzophenone.

    90

    Faraday examined also the electrolysis of certain fused salts such as lead chloride and silver chloride.

    91

    Farms adjacent to the rivers were for a time increased in richness by the alkaline salts, which in diffuse form might be valuable plant foods, and then suddenly become valueless when the concentration of alkali had reached a degree beyond that which the ordinary plants would endure.

    92

    For acids its value is usually rather less than for salts at equivalent concentrations.

    93

    For example, episomorphs of white potash alum and violet chrome alum, of white magnesium sulphate and green nickel sulphate, and of many other pairs of salts, have been obtained.

    94

    For ornamental work lacquering divides favour with colouring - sometimes done with coloured lacquers, but often with chemical colourings, of which the copper and iron salts are the chief basis.

    95

    For sodium salts not mentioned below reference should be made to articles wherein the acid is treated, unless otherwise indicated.

    96

    For the manufacture of Epsom salts and for other hydrated magnesium sulphates see Magnesium.

    97

    For the nitrite, see Nitrogen, for the nitrate see Saltpetre and for the cyanide see Prussic Acid; for other salts see the articles wherein the corresponding acid receives treatment.

    98

    For the oxyhalogen salts see Chlorate, Chlorine, Bromine and Iodine.

    99

    For the quantitative determination of the metal, the salts are precipitated by caustic potash, the precipitate washed, dried and heated, and finally weighed as the dioxide.

    100

    For the salts of other sulphur acids, see Sulphur.

    101

    For these reasons, one must assume the existence of pentavalent nitrogen in the diazonium salts, in order to account for their basic properties.

    102

    For this purpose the cold solution is treated with hydrochloric acid, which precipitates lead, silver and mercurous salts as chlorides.

    103

    Formerly it was used for the preparation of the metal, but the inaccessibility of its source, and the fact that it is not sufficiently pure to be employed without some preliminary treatment, caused it to be abandoned in favour of other salts.

    104

    From this source all soils contain small proportions of sodium in soluble forms, hence the ashes of plants, although they preferably imbibe potassium salts, contain traces and sometimes notable quantities of sodium salts.

    105

    Further he prepared a large number of substances, including the chlorides and other salts of lead, tin, iron, zinc, copper, antimony and arsenic, and he even noted some of the phenomena of double decomposition.

    106

    Gallium forms colourless salts, which in neutral dilute aqueous solutions are converted on heating into basic salts.

    107

    Generally speaking, sodium salts closely resemble the corresponding potassium salts, and their methods of preparation are usually the same.

    108

    Gerland contributed to our knowledge of vanadyl salts and the vanadic acids.

    109

    Germanium compounds on fusion with alkaline carbonates and sulphur form salts known as thiogermanates.

    110

    Gladstone, 2 at an early period of spectroscopy, examined the absorption spectra of the solution of salts, each constituent of which was coloured.

    111

    Gold and copper salts give a metallic bead without an incrustation.

    112

    Graham's work was developed by Liebig, who called into service many organic acids - citric, tartaric, cyanuric, comenic and meconic - and showed that these resembled phosphoric acid; and he established as the criterion of polybasicity the existence of compound salts with different metallic oxides.

    113

    Hantzsch (Ber., 18 99, 3 2, pp. 59 o, 3089) considers that the oxyazo compounds are to be classed as pseudoacids, possessing in the free condition the configuration of quinone hydrazones, their salts, however, being of the normal phenolic type.

    114

    Hantzsch (Ber., 1901, 34, p. 3337) has shown that in the action of alcohols on diazonium salts an increase in the molecular weight of the alcohol and an accumulation of negative groups in the aromatic nucleus lead to a diminution in the yield of the ether produced and to the production of a secondary reaction, resulting in the formation of a certain amount of an aromatic hydrocarbon.

    115

    He did believe in the immediate use for therapeutics of the salts and other preparations which his practical skill enabled him to make.

    116

    He formed a comprehensive theory of the variations of climate with latitude and season, and was convinced of the necessity of a circulation of water between the sea and rivers, though, like Plato, he held that this took place by water rising from the sea through crevices in the rocks, losing it .s dissolved salts in the process.

    117

    He has also shown that the nitrophenols yield, in addition to the colourless true nitrophenol ethers, an isomeric series of coloured unstable quinonoid aci-ethers, which have practically the same colour and yield the same absorption spectra as the coloured metallic salts.

    118

    He mentioned as an important exception the case of ferric ferrocyanide, which, when dissolved in oxalic acid, transmits the rays in great abundance, though the same rays be absorbed both by ferrocyanides and by ferric salts.

    119

    He obtained selenic acid in 1827 and showed that its salts are isomorphous with the sulphates, while a few years later he proved that the same thing is true of the manganates and the sulphates, and of the permanganates and the perchlorates.

    120

    He took the same course soon afterwards with four other papers, two of which - "On the quantity of acids, bases and salts in different varieties of salts" and "On a new and easy method of analysing sugar," contain his discovery, regarded by him as second in importance only to the atomic theory, that certain anhydrous salts when dissolved in water cause no increase in its volume, his inference being that the "salt enters into the pores of the water."

    121

    Hence it is of the utmost importance to avoid the use of salts of this metal whenever it is necessary - as in diabetic coma - to increase the alkalinity of the blood rapidly.

    122

    Here it is further boiled down until the greater part or nearly all of the water has been removed, and until the salts on cooling would set to a solid mass.

    123

    Hess now observed that in the process of mixing such neutral solutions no thermal effect was produced - that is, neutral salts in aqueous solution could apparently interchange their radicals without evolution or absorption of heat.

    124

    His most important achievement was to define "salts" - a term formerly used in the most loose and indeterminate way - as the compounds formed by the union of acids and bases, and further to distinguish between neutral, basic and acid salts.

    125

    His work also included observations on putrefaction and fermentation, which he spoke of as sisters, on the nature of salts, and on the preparation of pure metals.

    126

    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.

    127

    Hydrogen may also be obtained by the action of zinc on ammonium salts (the nitrate excepted) (Lorin, Comptes rendus, 1865, 60, p. 745) and by heating the alkali formates or oxalates with caustic potash or soda, Na2C204+2NaOH = H 2 +2Na 2 CO 3.

    128

    If forms two series of salts, one, the uranous compounds, are derived from the oxide U02, the other, the uranyl compounds, contain the divalent group U02.

    129

    If silver nitrate salts be administered for a long period as a medication, the skin that is exposed to light becomes of a bluish-grey colour, which is extremely persistent.

    130

    If the gas be mixed with the vapour of carbon disulphide, the mixture burns with a vivid lavender-coloured flame Nitric oxide is soluble in solutions of ferrous salts, a dark brown solution being formed, which is readily decomposed by heat, with evolution of nitric oxide.

    131

    If the heating be with charcoal, the trimetallic salts of the alkalis and alkaline earths are unaltered, whilst the monoand di-salts give free phosphorus and a trimetallic salt.

    132

    If the nitrogen atom in the quaternary ammonium salts be in combination with four different groups, then the molecule is asymmetrical, and the salt can be resolved into optically active enantiamorphous isomerides.

    133

    If two solutions containing the salts AB and CD be mixed, double decomposition is found to occur, the salts AD and CB being formed till a certain part of the first pair of substances is transformed into an equivalent amount of the second pair.

    134

    In 1826 he described the prismatically-coloured films of metal, known as Nobili's' rings, deposited electrolytically from solutions of lead and other salts when the anode is a polished iron plate and the cathode is a fine wire placed vertically above it.

    135

    In accordance with his theory of the constitution of salts Werner formulates the hexahydrate as CrC12 (OH2)4 C1.2H20.

    136

    In addition, certain inorganic salts, particularly certain compounds of potassium, are apparently necessary, but they seem to take no part in the chemical changes which take place.

    137

    In all probability no excess of soluble lime salts in the blood or lymph can ever be deposited in healthy living tissues.

    138

    In formulating these facts Liebig at first retained the dualistic conception of the structure of acids; but he shortly afterwards perceived that this view lacked generality since the halogen acids, which contained no oxygen but yet formed salts exactly similar in properties to those containing oxygen, could not be so regarded.

    139

    In its chemical affinities zirconium resembles titanium, cerium and thorium; it occurs in company with these elements, and is tetravalent in its more important salts.

    140

    In its chemical combinations sodium is usually monovalent; its salts are generally soluble in water, the least soluble being the metantimonate.

    141

    In its tertiary stages - and also earlier - this disease yields in the most rapid and unmistakable fashion to iodides; so much so that the administration of these salts is at present the best means of determining whether, for instance, a cranial tumour be syphilitic or not.

    142

    In many cases it acts as a reducing agent (when used in the presence of acids); thus, permanganates are reduced to manganous salts, iodates are reduced with liberation of iodine, &c., 2KMnO 4 + 550 2 + 2H 2 0 = K 2 SO 4 + 2MnSO 4 + 2H 2 SO 4; 2K103+ 550 2 + 4H 2 O =1 3 + 2KHSO 4 + 3H2S04.

    143

    In order to separate caesium from rubidium, use is made of the different solubilities of their various salts.

    144

    In particular, the salts of potassium, sodium and ammonium were carefully investigated, but sodium and potassium salts were rarely differentiated.

    145

    In such cases the waters are alkaline, and contain various salts in solution which are deposited as a white rim round the basin towards the end of the summer when the amount of water has been greatly reduced by evaporation.

    146

    In such salts as potassium chloride the ions seem to be simple throughout" a wide range of concentration since the transport numbers for the same series of concentrations as those used above run Potassium chloride 0.5 1 5, 0.515, 0.514, 0.513, 0.509, 0.508, 0.507, 0.507, 0.506.

    147

    In the above account we have indicated the procedure adopted in the analysis of a complex mixture of salts.

    148

    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.

    149

    In the combined state nitrogen is fairly widely distributed, being found in nitre, Chile saltpetre, ammonium salts and in various animal and vegetable tissues and liquids.

    150

    In the end much inorganic nitrogen salts must be added to the sea both in the above way and as the result of the putrefaction of the dead substance of terrestrial animals and plants.

    151

    In the form of certain salts iodine is very widely used, for internal administration in medicine and in the treatment of many conditions usually classed as surgical, such as the bone manifestations of tertiary syphilis.

    152

    In the former process it is obtained in the form of a dilute aqueous solution, in which also the colouring matters of the wine, salts, &c., are dissolved; and this impure acetic acid is what we ordinarily term vinegar.

    153

    In the ordinary laboratory the Bunsen flame has become universal, and a number of substances, such as the salts of the alkalis and alkaline earths, show characteristic spectra when suitably placed in it.

    154

    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.

    155

    In the stomach potassium salts neutralize the gastric acid, and hence small doses are useful in hyperchloridia.

    156

    Indeed, where men live mainly on milk and flesh, consuming the latter raw or roasted, so that its salts are not lost, it is not necessary to add sodium chloride, and thus we understand how the Numidian nomads in the time of Sallust and the Bedouins of Hadramut at the present day never eat salt with their food.

    157

    It acts as a weak base and forms salts with one equivalent of an acid.

    158

    It also gives rise to super-acid salts, such as KHTe03 H2Te03; K 2 TeO 3.3TeO 2.

    159

    It attacks most metals readily, usually with production of a nitrate or hydrated oxide of the metal and one or other of the oxides of nitrogen, or occasionally with the production of ammonium salts; magnesium, however, liberates hydrogen from the very dilute acid.

    160

    It behaves as a monobasic acid and forms unstable salts.

    161

    It burns, and also, like sulphuretted hydrogen, precipitates many metals from solutions of their salts.

    162

    It combines directly with many metallic salts.

    163

    It combines readily with alkaline and other chlorides to form double salts, e.g.

    164

    It combines with many metals to form sulphides, and also decomposes many metallic salts with consequent production of sulphides, a property which renders it extremely useful in chemical analysis.

    165

    It combines with the chlorides of the alkali metals to form characteristic double salts of the type OsC1 4.2MC1 (osmichlorides).

    166

    It combines with the sulphates of the alkali metals to form double salts.

    167

    It consists largely of a dark brown or black sandy loam, finely comminuted, the richness of which in organic matter and mineral salts induces rapidity of growth, and the strength and durability of which render it capable of a long succession of crops.

    168

    It decomposes ammonium salts.

    169

    It dissolves in acids forming cobaltous salts, and on exposure to air it rapidly absorbs oxygen, turning brown in colour.

    170

    It dissolves in alkalis to form well-defined crystalline salts; potassium aurate, KAu0 2.3H 2 O, is very soluble in water, and is used in electrogilding.

    171

    It dissolves most organic compounds, resins, hydrocarbons, fatty acids and many metallic salts, sometimes forming, in the latter case, crystalline compounds in which the ethyl alcohol plays a role similar to that of water of crystallization.

    172

    It fires when heated in air, and dissolves in acids to form uranous salts.

    173

    It forms crystalline compounds with bromine and with many metallic salts.

    174

    It forms crystallizable salts with potassium and calcium hydrates, and functions as a weak acid forming salts named plumbates.

    175

    It forms double salts with metallic chlorides and with the hydrochlorides of organic bases.

    176

    It forms double salts with the alkaline sulphates.

    177

    It forms double salts with the chlorides of the alkali metals.

    178

    It forms double salts, named zircono-fluorides, which are isomorphous with the stanniand titani-fluorides.

    179

    It forms many crystalline salts and absorbs carbon dioxide.

    180

    It forms many double salts with other metallic fluorides.

    181

    It forms several double salts, e.g.

    182

    It gives mono-metallic salts of the type NC NHM when treated with aqueous or alcoholic solutions of alkalis.

    183

    It gives rise to salts, termed the tantalates.

    184

    It has all the characteristics of an acid, dissolving many metals with evolution of hydrogen and formation of salts, called iodides.

    185

    It has also been shown that when different salts of the amine are used, their catalytic influence varies in amount and is almost proportional to their degree of ionization in aqueous solution.

    186

    It has strong basic properties, absorbs carbon dioxide readily, and forms welldefined crystalline salts.

    187

    It is a monobasic acid, forming one normal and two acid potassium salts, and basic salts with iron, aluminium, lead and copper.

    188

    It is a very weak base, salts being only formed with mineral acids, and these are dissociated by water.

    189

    It is a yellow, microcrystalline powder, soluble in water, alcohol and chloroform, and forming readily decomposed salts with acids.

    190

    It is almost insoluble in water, but readily dissolves in ammonium salts.

    191

    It is apparent that metallic salts of organic acids would, in aqueous solution, be ionized, the positive ion being the metal, and the negative ion the acid residue.

    192

    It is distinguished from the other members of the series by certain characteristic properties; for example, it shows an aldehydic character in reducing silver salts to metallic silver, and it does not form an acid chloride or an acid anhydride.

    193

    It is extensively employed for the preparation of other potassium salts, but the largest quantity (especially of the impure product) is used in the production of artificial manures.

    194

    It is insoluble in acids and exists in several hydrated forms. The osmiates, corresponding to the unknown trioxide 0503, are red or green coloured salts; the solutions are only stable in the presence of excess of caustic alkali; on boiling an aqueous solution of the potassium salt it decomposes readily, forming a black precipitate of osmic acid, H20s04.

    195

    It is insoluble in water, while its salts are readily soluble.

    196

    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.

    197

    It is monobasic and yields salts which only crystallize with great difficulty; when liberated, from these salts by a mineral acid it forms a syrupy nonvolatile mass.

    198

    It is not possible to prepare the normal carbonate by precipitating magnesium salts with sodium carbonate.

    199

    It is obtained by the dry distillation of nitrogenous vegetable and animal products; by the reduction of nitrous acid and nitrites with nascent hydrogen; and also by the decomposition of ammonium salts by alkaline hydroxides or by slaked lime, the salt most generally used being the chloride (sal-ammoniac, q.v.) thus 2NH 4 C1+Ca(OH) 2 =CaC1 2 +2H 2 O+2NH 3.

    200

    It is of consequence that they should, as far as possible, be free from excess of alkali and all other salts and foreign ingredients which may have an injurious effect on the skin.

    201

    It is only the water that freezes; the dissolved salts are excluded in the process in a regular order according to temperature.

    202

    It is possible to distinguish between double salts and salts of compound acids.

    203

    It is precipitated as the metal from solutions of its salts by the metals of the alkalis and alkaline earths, zinc, iron, copper, &c. In its chemical affinities it resembles arsenic and antimony; an important distinction is that it forms no hydrogen compound analogous to arsine and stibine.

    204

    It is rapidly dissolved by dilute acids, with the evolution of hydrogen and the formation of magnesium salts.

    205

    It is readily soluble in warm dilute mineral acids forming cobaltous salts.

    206

    It is used largely as an artificial manure, and also for the preparation of other ammonium salts.

    207

    It may also be prepared by heating formic and oxalic acids (or their salts) with concentrated sulphuric acid (in the case of oxalic acid, an equal volume of carbon dioxide is produced); and by heating potassium ferrocyanide with a large excess of concentrated sulphuric acid, K 4 Fe(CN) 6 -i-6H2S04+6H20=2K2S04+FeS04+3(NH4)2S04+6C0.

    208

    It may happen that the crystals do not form double salts, and are only miscible in certain proportions.

    209

    It possesses all the characteristic properties of an aldehyde; being readily oxidized to benzoic acid; reducing solutions of silver salts; forming addition products with hydrogen, hydrocyanic acid and sodium bisulphite; and giving an oxime and a hydrazone.

    210

    It precipitates many metals from solutions of their salts.

    211

    It readily yields basic salts.

    212

    It reduces silver salts rapidly.

    213

    It seems probable that the effect of the salts is inconsiderable, and that the governing condition is the temperature at which the cement has been burnt.

    214

    It was found that substances like mineral salts, which crystallize well from solution, passed such membranes with comparative ease, while the jelly-like substances such as albumen passed with extreme slowness if at all.

    215

    Its composition approaches the formula CaOC1 2, and it is regarded as a double salt of calcium chloride and hypochlorite, which by the action of water splits up into a mixture of these salts.

    216

    Its double salts with the alkaline fluorides are very important, and serve for the separation of the metal from columbium and titanium.

    217

    Its salts are more soluble in water than those of the normal acid.

    218

    Its salts are reddish violet in colour, and give a characteristic absorption spectrum.

    219

    Its salts colour the Bunsen flame a bright green.

    220

    Its salts may be obtained in some cases by heating the corresponding nitrates, but the method does not give good results.

    221

    Jochem (Ber., 1901, 34, p. 3337), who arrived at the conclusion that the normal decomposition of diazonium salts by alcohols results in the formation of phenolic ethers, but that an increase in the molecular weight of the alcohol, or the accumulation of negative groups in the aromatic nucleus, diminishes the yield of the ether and increases the amount of the hydrocarbon formed.

    222

    Kehrmann showed that aposafranine could be diazotized in the presence of cold concentrated sulphuric acid, and the diazonium salt on boiling with alcohol yielded phenylphenazonium salts.

    223

    Lacombe in 1904 obtained the pure salts by fractional crystallization of the nitric acid solution with magnesium nitrate in the presence of bismuth nitrate.

    224

    Lanthanum hydroxide, La(OH) 3, is a white amorphous powder formed by precipitating lanthanum salts by potassium hydroxide.

    225

    Large doses of these salts are used to remove fluid in dropsy.

    226

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

    227

    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.

    228

    Lastly, salts amount to 3.

    229

    Lead generally functions as a divalent element of distinctly metallic character, yielding a definite series of salts derived from the oxide PbO.

    230

    Lead salts usually produce constipation, and lead is an active ecbolic. Lead is said to enter the blood as an albuminate in which form it is deposited in the tissues.

    231

    Lead sulphate, PbSO 4, occurs in nature as the mineral anglesite (q.v.), and may be prepared by the addition of sulphuric acid to solutions of lead salts, as a white precipitate almost insoluble in water (1 in 21,739), less soluble still in dilute sulphuric acid (1 in 36,504) and insoluble in alcohol.

    232

    Like these they require water, small but indispensable quantities of salts of potassium, magnesium, sulphur and phosphorus, and supplies of carbonaceous and nitrogenous materials in different stages of complexity in the different cases.

    233

    Lime is transported in solution as sulphate and bicarbonate, both of which salts are soluble to some extent in water.

    234

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

    235

    Litharge is much used for the preparation of lead salts, for the manufacture of oil varnishes, of certain cements, and of lead plaster, and for other purposes.

    236

    Magnesia alba, a white bulky precipitate obtained by adding sodium carbonate to Epsom salts,is a mixture of Mg(CO 3 H) (OH) 2H 2 O,Mg(CO 3 H) (OH) and Mg(OH) 2.

    237

    Magnesium chloride readily forms double salts with the alkaline chlorides.

    238

    Magnesium hydroxide is a white amorphous solid which is only slightly soluble in water; the solubility is, however, greatly increased by ammonium salts.

    239

    Magnesium hydroxide Mg(OH) 2, occurs native as the minerals brucite and nemalite, and is prepared by precipitating solutions of magnesium salts by means of caustic soda or potash.

    240

    Magnesium sulphate amounts to 4.7% of the total salts of sea-water according to Dittmar, but to 23.6% of the salts of the Caspian according to Lebedinzeff; in the ocean magnesium chloride amounts to 10.9% of the total salts, in the Caspian only to 4.5%; on the other hand calcium sulphate in the ocean amounts to 3.6%, in the Caspian to 6.9 This disparity makes it extremely difficult to view ocean water as merely a watery extract of the salts existing in the rocks of the land.

    241

    Manganese salts can be detected by the amethyst colour they impart to a borax-bead when heated in the Bunsen flame, and by the green mass formed when they are fused with a mixture of sodium carbonate and potassium nitrate.

    242

    Manganese, though belonging (with chromium) to the iron group of metals, is commonly classed as a paramagnetic, its susceptibility being very small in comparison with that of the recognized ferromagnetics; but it is remarkable that its atomic susceptibility in solutions of its salts is even greater than that of iron.

    243

    Many hydrated forms of the sulphate are known, as are also double salts of the sulphate with potassium, sodium, ammonium, thallium and cadmium sulphates.

    244

    Many of the ammonium salts are made from the ammoniacal liquor of gas-works, by heating it with milk of lime and then absorbing the gas so liberated in a suitable acid.

    245

    Many of the Egyptian rocks in the desert areas and at the cataracts are coated with a highly polished film, of almost microscopic thinness, consisting chiefly of oxides of iron and manganese with salts of magnesia and lime.

    246

    Many other synthetical processes for the production of the acid or its salts are known.

    247

    Many salts of the acid are known and, with the exception of those of the alkali metals, they are difficultly soluble in water.

    248

    Molybdenum trioxide, like chromium trioxide, is an acidic oxide, and forms salts known as molybdates.

    249

    Moreover, while methylamine, dimethylamine, and trimethylamine increase in basicity corresponding to the introduction of successive methyl groups, phenylamine or aniline, diphenylamine, and triphenylamine are in decreasing order of basicity, the salts of diphenylamine being decomposed by water.

    250

    Most other carbonates are formed by precipitation of salts of the metals by means of alkaline carbonates.

    251

    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.

    252

    Nitrous acid, HN02, is found to some extent in the form of its salts in the atmosphere and in rain water.

    253

    Normal cadmium carbonates are unknown, a white precipitate of variable composition being obtained on the addition of solutions of the alkaline carbonates to soluble cadmium salts.

    254

    Notwithstanding the false idea which prompted the researches of the alchemists, many advances were made in descriptive chemistry, the metals and their salts receiving much attention, and several of our important acids being discovered.

    255

    Now dead animal substance and the excreta of animals decompose in the long run into carbonic acid, water and mineral salts, and so there is a continual destruction of animal substance both on the land and in the sea.

    256

    Now Hittorf's transport number, in the case of simple salts in moderately dilute solution, gives us the ratio between the two ionic velocities.

    257

    Numerous other salts of zinc, used in medicine, are of value as containing this metal.

    258

    Numerous salts, termed sulphites, are known.

    259

    Of mineral constituents, whether used alone or in mixture with nitrogenous manures, phosphates are much more effective than mixtures of salts of potash, soda and magnesia.

    260

    Of recent years the introduction of various organic compounds as precipitants or reagents has reduced the labour of the process; and advantage has also been taken of the fairly complex double salts which these metals form with compounds.

    261

    On heating, they decompose, forming basic tetrammine salts.

    262

    On permeable soils, especially those of the terrace lands along the valleys, the soluble salts commonly known as alkali were gradually leached out and carried by the percolating waters towards the lower lands, where, reaching the surface, the alkali was left as a glistening crust or as pools of inky blackness.

    263

    On pouring a solution of chromous chloride into a saturated solution of sodium acetate, a red crystalline precipitate of chromous acetate is produced; this is much more permanent in air than the other chromous salts and consequently can be used for their preparation.

    264

    On the chromophoreauxochrome theory (the nitro group being the chromophore, and the hydroxyl the auxochrome) it is necessary in order to explain the high colour of the metallic salts and the colourless alkyl and aryl derivatives to assume that the auxochromic action of the hydroxyl group is only brought strongly into evidence by salt formation.

    265

    On the light, poor sands of Saxony Herr Schultz, of Lupitz, made use of serradella, yellow lupins and vetches as green manures for enriching the land in humus and nitrogen, and found the addition of potash salts and phosphates very profitable for the subsequent growth of potatoes and wheat.

    266

    On the other hand, solution of mineral acids and salts conduct the current with chemical decomposition - they are called electrolytes.

    267

    On the other hand, they are much weaker bases than the aliphatic amines, their salts undergoing hydrolytic dissociation in aqueous solution.

    268

    On the preparation of pure strontium salts, see Adrian and Bougarel, Journ.

    269

    On this account the salts of soda are of less importance than those of potash.

    270

    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.

    271

    One can look on sea-water as a mixture of very dilute solutions of particular salts, each one of which after the lapse of sufficient time fills the whole space as if the other constituents did not exist, and this interdiffusion accounts easily for the uniformity of composition in the sea-water throughout the whole ocean, the only appreciable difference from point to point being the salinity or degree of concentration of the mixed solutions.

    272

    Only stannous salts (not stannic) give a precipitate of calomel in mercuric chloride solution.

    273

    Only the salts of the alkali metals are soluble in water.

    274

    Other basic salts are known.

    275

    Other instances of the isomorphism of thallous with potassium salts are the nitrates, phosphates, hydrazoates, sulphates, chromates, selenates, and the analogously constituted double salts, and also the oxalates, racemates and picrates.

    276

    Owing, however, to its poverty in that form of nitrogenous compound called gluten, so abundant in wheat, barley-flour cannot be baked into vesiculated bread; still it is a highlynutritious substance, the salts it contains having a high proportion of phosphoric acid.

    277

    Oxalic acid is very poisonous, and by reason of its great similarity in appearance to Epsom salts, it has been very frequently mistaken for this substance with, in many cases, fatal results.

    278

    Oxidizing agents (ferric chloride, &c.) give a blue precipitate with solutions of its salts.

    279

    Oxy-salts of gold are almost unknown, but the sulphite and thiosulphate form double salts.

    280

    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.

    281

    P. Pfeiffer (Berichte, 1904, 37, p. 4 2 55) has shown that chromium salts of the type [Cr{C2H4(NH2)2}2X2]X exist in two stereo-isomeric forms, namely, the cisand transforms, the dithiocyan-diethylenediamine-chromium salts being the transsalts.

    282

    Permanganates are the salts of permanganic acid, HMnO 4.

    283

    Potassium cyanide, KNC, and sodium cyanide, NaNC, are two of the most important of the salts of hydrocyanic acid, the former being manufactured in large quantities for consumption in the extraction of gold.

    284

    Potassium salts are strongly diuretic, acting directly on the renal epithelium.

    285

    Pott showed that it did not contain iron and that it yielded a definite series of salts, whilst in 1774 C. Scheele proved that it was the oxide of a distinctive metal.

    286

    Reducing agents, such as sulphurous acid and sulphuretted hydrogen, convert the chromates into chromic salts.

    287

    Richter contributed to the knowledge of the quantitative composition of salts.

    288

    Salts of ammonium were also known; while alum was used as a mordant in dyeing.

    289

    Schroeder the silver salts of the fatty acids exhibit additive relations; an increase in the molecule of CH2 causes an increase in the molecular volume of about 15'3.

    290

    Several basic carbonates are known, being formed by the addition of beryllium salts to solutions of the alkaline carbonates; the normal carbonate is prepared by passing a current of carbon dioxide through water containing the basic carbonate in suspension, the solution being filtered and concentrated over sulphuric acid in an atmosphere of carbon dioxide.

    291

    Several hydrated forms are known, yielding salts known as columbates.

    292

    Should it be thought that the traces of the more valuable sorts of plant food (such as compounds of nitrogen, phosphates, and potash salts) existing in ordinary brook or river water can never bring an appreciable amount of manurial matter to the soil, or exert an appreciable effect upon the vegetation, yet the quantity of water used during the season must be taken into account.

    293

    Since the earliest quantitative analyses of sea-water were made by Lavoisier in 1772, Bergman in 177 4, Vogel in 1813 and Marcet in 1819 the view has been held that the salts are present in sea-water in the form in which they are deposited when the water is evaporated.

    294

    Since the free acid would be dibasic, two series of salts exist, namely, the neutral and acid salts.

    295

    Since the salts, both before and after mixture, exist mainly as dissociated ions, it is obvious that large thermal effects can only appear when the state of dissociation of the products is very different from that of the reagents.

    296

    Sjdgren to contain salts like those of sulphur-springs.

    297

    Sodium and potassium hydroxide solutions precipitate green chromium hydroxide from solutions of chromic salts; the precipitate is soluble in excess of the cold alkali, but is completely thrown down on boiling the solution.

    298

    Sodium combines directly with the halogens to form salts which are soluble in water and crystallize in the cubic system.

    299

    Sodium is most distinctly recognized by the yellow coloration which volatile salts impart to a Bunsen flame, or, better, by its emission spectrum which has a line (double), the Fraunhofer D, line, in the yellow (the wave-lengths are 5896 and 5890).

    300

    Sodium salts also form essential ingredients in all animal juices.

    301

    Sodium salts have not the depressant effect so marked in those of potassium.

    302

    Solutions of lead salts (colourless in the absence of coloured acids) are characterized by their behaviour to hydrochloric acid, sulphuric acid and potassium chromate.

    303

    Some of them, like the Kreuzbrunnen and the Ferdinandsbrunnen, contain alkaline-saline waters which resemble those of Carlsbad, except that they are cold and contain nearly twice the quantity of purgative salts.

    304

    Stannic Fluoride, SnF 4, is obtained in solution by dissolving hydrated stannic oxide in hydrofluoric acid; it forms a characteristic series of salts, the stannofluorides, M 2 SnF 6, isomorphous with the silico-, titano-, germanoand zirconofluorides.

    305

    Strontium salts may be recognized by the characteristic crimson colour they impart to the flame of the Bunsen burner and by the precipitation of the insoluble sulphate.

    306

    Such a simple formula is only possible because the salts of sea-water are of such uniform composition throughout the whole ocean that the chlorine bears a constant ratio to the total salinity as newly defined whatever the degree of concentration.

    307

    Such mixtures are obtained by the action of alkaline hypochlorites on manganous salts, or by suspending manganous carbonate in water and passing chlorine through the mixture.

    308

    Such potassiferous silicates are found in almost all rocks, both as normal and as accessory components; and their disintegration furnishes the soluble potassium salts which are found in all fertile soils.

    309

    Telluric acid, H2Te04, is obtained in the form of its salts when tellurium is fused with potassium carbonate and nitre, or by the oxidizing action of chlorine on a tellurite in alkaline solution.

    310

    Thallic salts are easily reduced to thallous by means of solution of sulphurous acid, and thus rendered amenable to the above reactions.

    311

    Thallous Perchlorate, T1C10 4, and periodate, Tl10 4, are interesting inasmuch as they are isomorphous with the corresponding potassium salts.

    312

    The absorption spectra of cobalt and didymium salts also offer many.

    313

    The acid and its salts are antipyretic and were used in Germany instead of salicylates in rheumatic fever.

    314

    The acid carbonates of the alkali metals can be prepared by saturating an aqueous solution of the alkaline hydroxide with carbon dioxide, M OH+ C02= Mhco 3, and from these acid salts the normal salts may be obtained by gentle heating, carbon dioxide and water being produced at the same time, 2Mhco 3 = M2C03+H02+C02.

    315

    The acid salts are obtained by the addition of one molecule of alkali to two molecules of the acid in concentrated alcoholic solution at a low temperature.

    316

    The acid salts have a neutral or slightly acid reaction.

    317

    The alkaline liquid is now transferred to vacuum pans, constructed in such a manner that the unchanged chloride, which " salts out " during the concentration, can be removed without disturbing the vacuum, and here at last a concentrated pure solution of KOH or NaOH is obtained which is sold in this state, or " finished " as solid caustic in the manner described in the section treating of the Leblanc soda.

    318

    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.

    319

    The analysis of manganese dioxide in 1774 led him to the discovery of chlorine and baryta; to the description of various salts of manganese itself, including the manganates and permanganates, and to the explanation of its action in colouring and decolourizing glass.

    320

    The anodes are made of retort-carbon or other chlorine-resisting material, and they are mounted in cells which serve as diaphragms. The material of these cells is usually cement, mixed with certain soluble salts which impart sufficient porosity to the material.

    321

    The barium and magnesium salts of this acid are formed when baryta and magnesia are fused with cobalt sesquioxide.

    322

    The bark, very dark externally, is an excellent tanning substance; the inner layers form the quercitron of commerce, used by dyers for communicating to fabrics various tints of yellow, and, with iron salts, yielding a series of brown and drab hues; the colouring property depends on a crystalline principle called quercitrin, of which it should contain about 8%.

    323

    The blackish brown sulphide precipitated from bismuth salts by sulphuretted hydrogen is insoluble in ammonium sulphide, but is readily dissolved by nitric acid.

    324

    The boiled salts, the crystals of which are small, are formed in a medium constantly agitated by boiling.

    325

    The bromide, CsBr, and iodide, CsI, resemble the corresponding potassium salts.

    326

    The calcium salt, when heated with the calcium salts of higher homologues, gives aldehydes.

    327

    The calcium salts distilled with calcium formate yield aldehydes r distilled with soda-lime, ketones result.

    328

    The caliche is worked up in loco for crude nitrate by extracting the salts with hot water, allowing the suspended earth to settle, and then transferring the clarified liquor, first to a cistern where it deposits part of its sodium chloride at a high temperature, and then to another where, on cooling, it yields a crop of crystals of purified nitrate.

    329

    The cell sap contains various substances in solution such as sugars, inulin, alkaloids, glucosides, organic acids and various inorganic salts.

    330

    The chief insoluble salts are the perchlorate, acid-tartrate and platinochloride.

    331

    The chromophoric groups are rarely strongly acid or basic; on the other hand, the auxochromes are strongly acid or basic and form salts very readily.

    332

    The citrates are a numerous class of salts, the most soluble of which are those of the alkaline metals; the citrates of the alkaline earth metals are insoluble.

    333

    The clear caustic soda liquor must be concentrated in such a way that the caustic soda cannot to any great extent be reconverted into sodium carbonate, and that the " salts " which it contains, sodium carbonate, sulphate, chloride, &c., can be separated during the process.

    334

    The cobaltous salts are formed when the metal, cobaltous oxide, hydroxide or carbonate, are dissolved in acids, or, in the case of the insoluble salts, by precipitation.

    335

    The decomposition products are generally the same as with the general albumin; it gives the biuret reaction; forms salts with acids and alkalies, but is essentially acid in nature.

    336

    The diazonium salts are characterized by their great reactivity and consequently are important reagents in synthetical processes, since by their agency the amino group in a primary amine may be exchanged for other elements or radicals.

    337

    The diketotetrahydrotriazoles, or urazoles, are formed by condensing urea derivatives with hydrazine salts, urazole itself resulting by the action of urea or biuret on hydrazine or its salts.

    338

    The dissolved salts (potassium, sodium, ammonium, calcium, magnesium, &c.) of the latex are generally nearly entirely absent from the wellprepared rubber.

    339

    The enclosed alga is protected by the threads (hyphae) of the fungus, and supplied with water and salts and, possibly, organic nitrogenous substances; in its turn the alga by means of its green or blue-green colouring matter and the sun's energy manufactures carbohydrates which are used in part by the fungus.

    340

    The esters of the acid may be obtained by distilling a mixture of the sodium or potassium salts and the corresponding alcohol with hydrochloric or sulphuric acids.

    341

    The evidence in favour of dissociation in the case of solutions does not apply to fused salts, and it is possible that, in their case, a series of molecular interchanges, somewhat like Grotthus's chain, may represent the mechanism of conduction.

    342

    The extent to which a soap is hydrolysed depends upon the acid and on the concentration of the solution; it is also affected by the presence of metallic salts, e.g.

    343

    The extraction of thorium salts from these minerals is a matter of much tedium.

    344

    The ferric and aluminium sulphates present are thus converted into insoluble basic salts, and the residue yields manganous sulphate when extracted with water.

    345

    The fine or stoved table salts are those white masses with which we are all familiar.

    346

    The first set may be called monometallic, the second dimetallic, and the third trimetallic salts.

    347

    The food is alike in both cases; it consists of water, certain inorganic salts, carbohydrates and proteins.

    348

    The free acid, which is obtained by treating the salts with acids, is an oily liquid smelling like prussic acid; it is very explosive, and the vapour is poisonous to about the same degree as that of prussic acid.

    349

    The free pararosaniline, C19H19N30, and rosaniline, C20H21N30, may be obtained by precipitating solutions of their salts with a caustic alkali, colourless precipitates being obtained, which crystallize from hot water in the form of needles or plates.

    350

    The gallium salts are precipitated by alkaline carbonates and by barium carbonate, but not by sulphuretted hydrogen unless in acetic acid solution.

    351

    The germanium salts are most readily recognized by the white precipitate of the disulphide, formed in acid solutions, on passing sulphuretted hydrogen.

    352

    The great similarity between the salts of the ocean and the gaseous products of volcanic eruptions at the present time, rich in chlorides and sulphates of all kinds, is a strong argument for the ocean having been salt from the beginning.

    353

    The hexammine salts are formed by the oxidizing action of air on dilute ammoniacal solutions of cobaltous salts, especially in presence of a large excess of ammonium chloride.

    354

    The impurities occasionally present in commercial citric acid are salts of potassium and sodium, traces of iron, lead and copper derived from the vessels used for its evaporation and crystallization, and free sulphuric, tartaric and even oxalic acid.

    355

    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.

    356

    The insoluble salts are rose-red or violet in colour.

    357

    The instrument thus adapted to the determination of densities exceeding that of water was called the hydrometer for salts.

    358

    The kelp obtained by any of these methods is then lixiviated with water, which extracts the soluble salts, and the liquid is concentrated, when the less soluble salts, which are chiefly alkaline chlorides, sulphates and carbonates, crystallize out and are removed.

    359

    The latter gives rise to salts, the peruranates, e.g.

    360

    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.

    361

    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.

    362

    The metal is quite permanent in dry air, but in moist air it becomes coated with a superficial layer of the oxide; it burns on heating to redness, forming a brown coloured oxide; and is readily soluble in mineral acids with formation of the corresponding salts.

    363

    The mineral occurs generally in lenticular deposits, which may reach a thickness of more than loo ft.; but it is mined only to a limited extent, most of the salt being obtained from brine springs and wells which derive their saline character from deposits of salts.

    364

    The mixed secondary amines are prepared by the action of alkyl iodides on the primary amines, or by heating salts of the primary amine with alcohols under pressure.

    365

    The molybdates are also capable of combining with other oxides (such as phosphorus and arsenic pentoxides) yielding very complex salts.

    366

    The monometallic salts are strongly acid, the dimetallic are neutral or faintly alkaline, whilst the soluble trimetallic salts are strongly alkaline.

    367

    The monometallic salts of the alkalis and alkaline earths may be obtained in crystal form, but those of the heavy metals are only stable when in solution.

    368

    The most efficient evaporating apparatus, as far as economy of fuel is concerned, is the vacuum-pan, of which from two to five are combined to form a set, but it has the drawback that the removal of the salts is much more difficult than with the ?,,..

    369

    The movement of water into the root-hairs is brought about by the osmotic action of certain salts in their cell-sap. Crops are, however, unable to absorb all the water present in the soil, for when the films become very thin they are held more firmly or cling with more force to the soil particles and resist the osmotic action of the root-hairs.

    370

    The neutral alkaline salts are soluble in water and show an alkaline reaction, the other neutral salts being either insoluble or difficultly soluble in water.

    371

    The neutral esters are as a rule insoluble in water and distil unchanged; on the other hand, the acid esters are generally soluble in water, are non-volatile, and form salts with bases.

    372

    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.

    373

    The nitroprussides are salts of the type M2Fe(NC)5.

    374

    The normal salts are all insoluble in water; the complex acid, hexatantalic acid, H $ Ta 6 0, 9 (which does not exist in the free state), forms soluble salts with the alkaline metals.

    375

    The old idea of the circulating blood being supersaturated with lime salts which in some way had first become liberated from atrophying bones, and then deposited, to form calcified areas in different tissues will have to be given up, as there is no evidence that this " metastatic " calcification ever takes place.

    376

    The outer surfaces of the mantle secrete' the shell, which is of the nature of a cuticle impregnated by calcareous salts.

    377

    The oxide and carbonate of magnesium are also invaluable as antidotes, since they form insoluble compounds with oxalic acid and salts of mercury, arsenic, and copper.

    378

    The oxides of type RO are soluble in water, the solution possessing a strongly alkaline reaction and rapidly absorbing carbon dioxide on exposure; they are basic in character and dissolve readily in acids with the formation of the corresponding salts.

    379

    The pentammine roseo-salts can be obtained from the action of concentrated acids, in the cold, on airoxidized solutions of cobaltous salts.

    380

    The phenomena which succeed each other are then very similar, whether A and B are two metals, such as lead and tin or silver and copper, or are a pair of fused salts, or are water and common salt.

    381

    The precipitate formed by sulphuretted hydrogen may contain the black mercuric, lead, and copper sulphides, dark-brown bismuth sulphide, yellow cadmium and arsenious sulphides, orange-red antimony sulphide, brown stannous sulphide, dull-yellow stannic sulphide, and whitish sulphur, the last resulting from the oxidation of sulphuretted hydrogen by ferric salts, chromates, &c. Warming with ammonium sulphide dissolves out the arsenic, antimony and tin salts, which are reprecipitated by the addition of hydrochloric acid to the ammonium sulphide solution.

    382

    The precipitated gold is washed, treated with salt and sulphuric acid to remove iron salts, roughly dried by pressing in cloths or on filter paper, and then melted with salt, borax and nitre in graphite crucibles.

    383

    The preparations of morphine are incompatible with salts of iron, copper and mercury, also with lime water and alkaline earths and substances containing tannin.

    384

    The primary products of the dissociation of albumins are the albumoses, characterized by not being coagulable by heat, more soluble than the albumins, having a far less complex composition, and capable of being " salted (7) out " by certain salts, and the peptones, similar to albumoses but not capable of being " salted out "; moreover, peptones are less complex than albumoses.

    385

    The principal impurities of crude vat-liquor are sodium hydrate and sulphide, the latter of which always leads to the formation of soluble double sulphur salts of sodium and iron.

    386

    The problem of magnesium reduction is in many respects similar to that of aluminium extraction, bait the lightness of the metal as compared, bulk for bulk, with its fused salts, and the readiness with which it burns when exposed to air at high temperatures, render the problem somewhat more difficult.

    387

    The proportion of sodium chloride in the water of the ocean, where it is mixed with small quantities of other salts, is on the average about 3.33%, ranging from 2.9% for the polar seas to 3.55% or more at the equator.

    388

    The proportions between the four salts AB, CD, AD and CB, which exist finally in solution, are found to be the same whether we begin with the pair AB and CD or with the pair AD and CB.

    389

    The pungent smelling salts snapped her out of the in-between place.

    390

    The researches of Liebig (1823), Liebig and Gay-Lussac (1824), and of Liebig again in 1838 showed the acid to be isomeric with cyanic acid, and probably (Hcno) 2, since it gave mixed and acid salts.

    391

    The roots are prevented from fulfilling their function of taking up water and salts from the soil; the leaves accordingly droop, and the whole plant wilts and in bad attacks dies.

    392

    The salt is " drawn " from the pan and placed (in the case of boiled salts) in small conical baskets hung round the pan to drain, and thence moulded in square boxes and afterwards stove-dried, or (in case of unboiled salts) " drawn " in a heap on to the " hurdles," on which it drains, and thence is carried to the store.

    393

    The salts are mostly of a yellowish colour.

    394

    The salts are obtained by the action of alkalies on the acid.

    395

    The salts are usually non-crystalline and fusible.

    396

    The salts have a faint pink colour, and show a faint absorption spectrum; the spark spectrum is brilliant and well characterized.

    397

    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.

    398

    The salts of benzoic acid are known as the benzoates and are mostly soluble in water.

    399

    The salts of hydrofluoric acid are known as fluorides and are easily obtained by the action of the acid on metals or their oxides, hydroxides or carbonates.

    400

    The salts of nitric acid, known as nitrates, are mostly readily soluble in water and crystallize well.

    401

    The salts of praseodymium are green in colour, and give a characteristic spark spectrum.

    402

    The salts of scandium are all colourless, the chloride and bromide corresponding in composition to Sc 2 X 6.12H 2 0; the fluoride is anhydrous.

    403

    The salts of sodium resemble potassium in their action on the alimentary tract, but they are much more slowly absorbed, and much less diffusible; therefore considerable amounts may reach the small intestine and there act as saline purgatives.

    404

    The salts of the acid are colourless or faintly yellow.

    405

    The salts of the acid are known as formates, and are mostly soluble in water, those of silver and lead being the least soluble.

    406

    The salts of the acid, however, are stable, the sodium salt in particular being largely used for photographic purposes under the name of "hypo."

    407

    The salts of the normal or orthoboric acid in all probability do not exist; metaboric acid, however, forms several well-defined salts which are readily converted, even by carbon dioxide, into salts of pyroboric acid.

    408

    The salts of this acid are well known; they are isomorphous with the silico-, stannoand zircono-fluorides.

    409

    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).

    410

    The salts show a characteristic absorption spectrum.

    411

    The salts tabulated are those of which the equivalent conductivity reaches a limiting value indicating that complete ionization is reached as dilution is increased.

    412

    The salts, known as the iodates, can be prepared by the action of the acid on a base, or sometimes by the oxidation of iodine in the presence of a base.

    413

    The scientific study of salts dates from this period, especial interest being taken in those compounds which possessed a medicinal or technical value.

    414

    The silver and mercury salts, when heated, yield the metal, with liberation of carbon dioxide and formation of free formic acid; and the ammonium salt, when distilled, gives some formamide, Hconh 2.

    415

    The soluble salts are removed by lixiviation, and the residue is boiled with lime to form the soluble calcium ferrocyanide, which is finally converted into the potassium salt by potassium chloride or carbonate.

    416

    The soluble salts are, when in the hydrated condition, also red, but in the anhydrous condition are blue.

    417

    The soluble trimetallic salts are decomposed by carbonic acid into a dimetallic salt and an acid carbonate.

    418

    The solution is strongly caustic. It turns yellow on exposure to air, absorbing oxygen and carbon dioxide and forming thiosulphate and potassium carbonate and liberating sulphuretted hydrogen, which decomposes into water and sulphur, the latter combining with the monosulphide to form higher salts.

    419

    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).

    420

    The species lepidolite is largely used for the manufacture of lithium and rubidium salts.

    421

    The spectra, for instance, of the oxides and haloid salts of the alkaline earths show great resemblance to each other, the bands being similar and similarly placed.

    422

    The Stassfurt deposits are of special importance for the sake of the associated salts of potassium and magnesium, such as carnallite and kainite.

    423

    The substances which we at present term anhydrous acids (acid oxides) only become, for the most part, capable of forming salts with metallic oxides after the addition of water, or they are compounds which decompose these oxides at somewhat high temperatures."

    424

    The sulphate combines with the alkaline sulphates to form double salts of the type Sc 2 (SO 4) 3.3K 2 SO 4.

    425

    The sulphates are treated with water, which dissolves the uranium and other soluble salts, while silica, lead sulphate, &c., remain; these are removed by filtration.

    426

    The symptoms of nerve-poisoning are due to the carbolic acid (or its salts) which circulate in the blood after all the sulphates in the blood have been used up in the formation of sulpho-carbolates (hence, during administration of carbolic acid, the urine should frequently be tested for the presence of free sulphates; as long as these occur in the urine, they are present in the blood and there is no danger).

    427

    The tertiary amines possess the power of combining with one molecular proportion of an alkyl iodide to form quaternary ammonium salts.

    428

    The time varies for the unboiled salts from twelve hours to three or four weeks, the larger crystals being allowed a longer time to form, and the smaller ones being formed more quickly.

    429

    The use of chemical antidotes, such as iron salts, is futile, as the drug has escaped into the blood from the stomach long before they can be administered.

    430

    The use of tin salts, especially stannic chloride, SnC1 4, enables dyers to weight all colours the same as black.

    431

    The usual doses of these salts are from five to thirty grains or more.

    432

    The value of wood ashes as a manure very much depends upon the carbonate and other salts of potash which they contain.

    433

    The washing is continued until the filtrate is free from salts or acids.

    434

    The water of the ocean is usually nearly saturated with calcium salts, which must continually be removed since they are always being added in the water brought down from the land.

    435

    The water taken up by the root from the soil contains nitrogenous and mineral salts which combine with the first product of photo-synthesis - a carbohydrate - to form more complicated nitrogen-containing food substances of a proteid nature; these are then distributed by other elements of the vascular bundles (the phloem) through the leaf to the stem and so throughout the plant to wherever growth or development is going on.

    436

    The watery fluid in which the globules are suspended holds certain proteids, carbohydrates and a small proportion of salts in solution.

    437

    The watery liquid known as rubber milk or latex is an emulsion consisting chiefly of a weak watery solution of proteids, carbohydrates and salts holding the liquid globules in suspension.

    438

    The wet refining process is more tedious and expensive, and is only exceptionally employed, as in the case of preparing the pure metal or its salts for pharmaceutical or chemical purposes.

    439

    Thechromites maybe looked upon as salts of chromium sesquioxide with other basic oxides, the most important being chromite (q.v.).

    440

    Their salts are easily dissociated.

    441

    Theoretical conceptions were revived by Stahl, who held that acids were the fundamentals of all salts, and the erroneous idea that sulphuric acid was the principle of all acids.

    442

    There are a number of warm mineral springs, containing principally salts of lime, used with success by both Arabs and Europeans in several kinds of disease.

    443

    There are three substances which can be relied on more or less to remove this compound, and the gas to be purified may be passed either through acid copper salts, through bleaching powder or through chromic acid.

    444

    There must be considerable dissociation of molecules, and as a first approximation it may be taken that of io molecules of most of the components about 9 (or in the case of magnesium sulphate 5) have been separated into their ions, and that it is only during slow concentration as in a natural saline that the ions combine to produce the various salts in the proportions set out in the above table.

    445

    These acid esters retain some of the characteristic properties of the acids, forming, for example, salts, with basic oxides.

    446

    These consist of galactin and lactochrome, substances peculiar to milk, discovered by Winter Blyth, with certain animal principles such as leucin, pepton, kreatin, tyrosin, &c. The salts in milk consist, according to the average of numerous analyses by Fleischmann, of the following Milk thus is not to be regarded as a definite chemical compound nor even as a mixture of bodies in fixed and invariable proportions.

    447

    These exhibit, in certain cases, marked crystallographical and other analogies with the corresponding salts of chromium and ferric iron.

    448

    These purgative sodium salts are most useful in the treatment of chronic constipation, and of the constipation associated with gout and hepatic dyspepsia.

    449

    These salts are considered to be derived from the hypothetical base OH 3.

    450

    These salts are derived from manganic acid H 2 Mn0 4.

    451

    These salts are employed in dyeing and various other industrial processes.

    452

    These salts are like those of tin; and the resemblance to this metal is clearly enhanced by the study of the alkyl compounds.

    453

    These salts are sucked up by the roots of plants, and by taking part in the process of nutrition are partly converted into oxalate, tartrate, and other organic salts, which, when the plants are burned, are converted into the carbonate, K 2 CO 3.

    454

    These salts cannot be converted either into the red salts or into the free acid.

    455

    These salts generally resemble the bichromates; they are yellow in colour, insoluble in water, soluble in acids, and decomposed by heat.

    456

    These salts have been extensively employed internally, and indeed they are still largely employed in the treatment of the more severe and difficult cases of nervous disease.

    457

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

    458

    These salts of magnesium may be regarded as the typical saline purgatives.

    459

    These sodium salts are crystalline solids which are readily soluble in water and are very explosive.

    460

    These soluble salts combine with the albumins in the body, and are deposited as minute granules of silver albuminate in the connective tissue of the skin papillae, serous membranes, the intima of arteries and the kidney.

    461

    They add on alkyl iodides readily, forming alkyl azonium salts.

    462

    They are all strong bases, readily forming salts with the mineral acids and double salts with the chlorides of gold, platinum and mercury.

    463

    They are formed by the action of nitrous fumes on ammoniacal solutions of cobaltous salts, or purpureo-salts, or by the mutual reaction of chlorpurpureosalts and alkaline nitrites.

    464

    They are precipitated from their alkaline solutions as cobalt sulphide by sulphuretted hydrogen, but this precipitation is prevented by the presence of citric and tartaric acids; similarly the presence of ammonium salts hinders their precipitation by caustic alkalis.

    465

    They are strong bases and form stable monacid salts.

    466

    They are usually insoluble in water, alcohol and ether; and their presence as solutes in vegetable and animal fluids is not yet perfectly understood, but it is probably to be connected with the presence of salts or other substances.

    467

    They are yellowish-red solids, which behave as weak bases, their salts undergoing hydrolytic dissociation in aqueous solution.

    468

    They discriminate between the red or erythro-salts, which are well crystallized, very explosive and unstable compounds, and which regenerate the colourless nitrolic acid on the addition of dilute mineral acids, and the leuco-salts, which are colourless salts obtained by warming the erythro-salts or by exposing them to direct sunlight.

    469

    They form many double salts and give a dark violet coloration with ferric chloride solution, this colour, however, gradually disappearing on standing, sulphur being precipitated.

    470

    They give the biuret and xanthoproteic reactions, and form salts with both acids and bases.

    471

    They may be prepared by the dry distillation of the ammonium salts.

    472

    They possess a delicate Laticiferous layer of protoplasm, with numerous small nuclei lining Tissue the walls, while the interior of the tube (corresponding with the cell-vacuole) contains a fluid called latex, consisting of an emulsion of fine granules and drops of very various substances suspended in a watery medium in which various other substances (salts, sugars, rubber-producers, tannins, alkaloids and various enzymes) are dissolved.

    473

    This acid cannot be isolated in the free condition, but many of its salts are known.

    474

    This acid, H 2 Sn0 3, is readily soluble in acids forming stannic salts, and in caustic potash and soda, with the formation of orthostannates.

    475

    This and other reasons led to his rejection of the dualistic hypothesis and the adoption, on the ground of probability, and much more from convenience, of the tenet that " acids are particular compounds of hydrogen, in which the latter can be replaced by metals "; while, on the constitution of salts, he held that " neutral salts are those compounds of the same class in which the hydrogen is replaced by its equivalent in metal.

    476

    This arrangement has the effect that the salts, as they separate out, slide down the sloping part and arrive in the central channel, which is not exposed to the fire-gases, so that they quietly settle there, without caking to the pan, until they are fished out by means of perforated ladles.

    477

    This destructive action is increased if the water contains sulphates or magnesium salts, both of which act chemically on the calcareous constituents of the cement.

    478

    This disease has been successfully treated with a spray of copper sulphate and lime, or sulphate of iron; solutions of these salts prevent the conidia from germinating.

    479

    This hydroxide is soluble in well cooled acids, forming solutions which contain cobaltic salts, one of the most stable of which is the acetate.

    480

    This is the term applied to certain deposits of alkaline salts, or their solutions, which occur, sometimes in very large quantities, in various parts of the world.

    481

    Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.

    482

    Those of the heavy metals are mostly insoluble in water, but are soluble in a solution of potassium cyanide, forming more or less stable double salts, for example KAg(NC)2, KAu(NC) 2.

    483

    Thus obtained it is a yellow powder, soluble in the mineral acids to form soluble salts, which are readily precipitated as basic salts when the solution is diluted.

    484

    Thus the chlorine oxyacids enumerated above form salts named respectively hypochlorites, chlorites, chlorates and perchlorates.

    485

    Tin forms two well-marked series of salts, in one of which it is divalent, these salts being derived from stannous oxide, SnO, in the other it is tetravalent, this series being derived from stannic oxide, Sn02.

    486

    Tin ore of excellent quality is found in the province of Bauchi, alkali salts are abundant in Kano province, iron ore and red and yellow ochres are found in Kontagora and other provinces, kaolin (china clay) and limestone in the west central regions.

    487

    Up to 1857 the utmost the dyer could add was " weight for weight," but an accidental discovery that year put dyers into the way of using tin salts in weighting with the result that they were enabled to add 40 oz.

    488

    Up to this point the separation of the salts has taken place in a fairly regular manner, but now the temperature begins to exert an influence, and some of the salts deposited in the cold of the night dissolve again partially in the heat of the day.

    489

    Various hydrates have been described, but they cannot be formed by precipitating a uranyl salt with an alkali, this reagent giving rise to salts termed uranates.

    490

    Villiger (Be y ., 1901, 34, pp. 2679, 3612) showed that many organic compounds (ethers, alcohols, aldehydes, ketones, &c.) behave towards acids, particularly the more complex acids, very much like bases and yield crystallized salts in which quadrivalent oxygen must be assumed as the basic element.

    491

    Water and carbonic acid are synthesized, under the action of sunlight, to form sugar, starch or some other carboh y drate and this is then combined with simple nitrogenous salts to form proteid.

    492

    Werner, four hydrated chromium chlorides exist, namely the green and violet salts, CrC1 3.6H 2 O, a hydrate, CrC1 3.10H 2 O and one CrC1 3.4H 2 0.

    493

    When heated with aniline and its salts it yields phenylrosindulin (German patent 67339 (1888)).

    494

    When mixed with sodium carbonate and heated on charcoal in the reducing flame lead salts yield malleable globules of metal and a yellow oxide-ring.

    495

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

    496

    With hydroflouric acid it yields uranous fluoride, UF 4, which forms double salts of the type MF UF 4.

    497

    With such salts alone is a valid comparison possible.

    498

    Zinc forms only one oxide, ZnO, from which is derived a wellcharacterized series of salts.

    499

    Zinc sulphate, like magnesium sulphate, unites with the sulphates of the potassium metals and of ammonium into crystalline double salts, ZnS04 R2S04-+-6H20, isomorphous with one another and the magnesium salts.

    500

    Zirconium hydroxide, Zr(OH) 4, as thus obtained, is quite appreciably soluble in water and easily in mineral acids, with formation of zirconium salts, e.g.