See also:

• BARIUM (symbol Ba, atomic weight 137'37 [0=16])

BARIUM (See also:

• SYMBOL (Gr. o-uµ(3oXov, a sign)

symbol Ba, atomic See also:

• WEIGHT

weight 137'37 [0=16])  , one of the metallic chemical elements included in the See also:

• GROUP

group of the alkaline earths . It takes its name from the See also:

• GREEK
• GREEK, ETRUSCAN AND

Greek 9apus (heavy) on See also:

• ACCOUNT
• ACCOUNT (through O. Fr. acont, Late Lat. comptum, cornputare, to calculate)

account of its presence in See also:

• BARYTES

barytes or heavy spar which was first investigated in r6o2 by V . Casciorolus, a shoemaker of See also:

• BOLOGNA
• BOLOGNA, GIOVANNI DA (1524–1608)

Bologna, who found that after ignition with combustible sub-stances it became phosphorescent, and on this account it was frequently called Bolognian See also:

• PHOSPHORUS (Gr. 4ws, light, sPEpety, to bear)

phosphorus . In 1774.K . W . See also:

• SCHEELE, KARL WILHELM (1742-1786)

Scheele, in examining a specimen of pyrolusite, found a new substance to be See also:

• PRESENT

present in the See also:

• MINERAL

mineral, for on treatment with sulphuric See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid it gave an insoluble See also:

• SALT (a common Teutonic word, cf. Dutch zout, Ger. Salz, Scand. salt; cognate with Gr. &Xs, Lat. sal)
• SALT, SIR TITUS, BART

salt which was afterwards shown to be identical with that contained in heavy spar . See also:

• BARIUM (symbol Ba, atomic weight 137'37 [0=16])

Barium occurs chiefly in the See also:

• FORM (Lat. forma)

form of barytes or heavy spar, BaSO4, and See also:

• WITHERITE

witherite, BaCOa, and to a less extent in baryto-See also:

• CALCITE

calcite, baryto-See also:

• CELESTINE (CAELESTINUS)
• CELESTINE, or CELESTITE

celestine, and various complex silicates . The See also:

• METAL
• METAL (through Fr. from Lat. metallum, mine, quarry, adapted from Gr. µATaXAov, in the same sense, probably connected with ,ueraAAdv, to search after, explore, µeTa, after, aAAos, other)

metal is difficult to isolate, and until recently it may be doubted whether the pure metal had been obtained . See also:

• SIR

Sir H . See also:

• DAVY, SIR HUMPHRY

Davy tried to electrolyse baryta, but was unsuccessful; later attempts were made by him using barium chloride in the presence of See also:

• MERCURY
• MERCURY (MERCU1uus)
• MERCURY (symbol Hg, atomic weight = 2oo)

mercury . In this way he obtained an See also:

• AMALGAM

amalgam, from which on distilling off the mercury the barium was obtained as a See also:

• SILVER

silver See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white See also:

• RESIDUE (through the French, from the Lat. residuum, a remainder, from residere, to remain)

residue . R .

See also:

• BUNSEN, CHRISTIAN CHARLES JOSIAS, BARON VON (1791-186o,)
• BUNSEN, ROBERT WILHELM VON (1811-1899)

Bunsen in 1854 electrolysed a thick See also:

• PASTE (O. Fr. paste, modern pate, Late Lat. pasta, whence also in Span., Port. and Ital., from Gr. 1r&vrrl or 1raara, barley porridge, or salted pottage, ir&ao'ety, to sprinkle with salt)

paste of barium chloride and dilute hydrochloric acid in the presence of mercury, at too° C., obtaining a barium amalgam, from which the mercury was separated by a See also:

• PROCESS

process of See also:

• DISTILLATION (from the Lat. distillare, more correctly destillare, to drop or trickle down)

distillation . A . N . Guntz (Comptes rendus, Igor, 133, p . 872) electrolyses a saturated See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution of barium chloride using a mercury See also:

• CATHODE

cathode and obtains a 3 %o barium amalgam; this amalgam is transferred to an See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron See also:

• BOAT (0. Eng. bdt; the true etymological connexion with Dutch and Ger. boot, Fr. bateau, Ital. battello presents great difficulties; Celtic forms are from O. Eng.)

boat in a wide See also:

• PORCELAIN

porcelain See also:

• TUBE (Lat. tuba)

tube and the tube slowly heated electrically, a See also:

• GOOD, JOHN MASON (1764-1827)

good yield of pure barium being obtained at about x000° C . The metal when freshly cut possesses a silver white lustre, is a little harder than See also:

• LEAD
• LEAD (pronounced iced)

lead, and is extremely easily oxidized on exposure; it is soluble in liquid See also:

• AMMONIA (NH3)

ammonia, and readily attacks both See also:

• WATER

water and See also:

• ALCOHOL

alcohol . Three oxides of barium are known, namely,. the monoxide, BaO, the dioxide, BaO2, and a suboxide, obtained by See also:

• HEATING

heating BaO with See also:

• MAGNESIUM [symbol Mg, atomic weight 24.32 (0 = 16)]

magnesium in a vacuum to 11oo° (Guntz, loc. cit., 1906, p . 359) . The monoxide is formed when the metal See also:

• BURNS, JOHN (1858– )
• BURNS, ROBERT (1759-1796)
• BURNS, SIR GEORGE

burns in See also:

• AIR (from an Indo-European root meaning " breathe," " blow ")
• AIR, or ASBEN

air, but is usually prepared by the ignition of the nitrate, See also:

• OXYGEN (symbol 0, atomic weight 16)

oxygen and oxides of See also:

• NITROGEN [symbol N., atomic weight 14.01, 0=16]

nitrogen being liberated . It can also be obtained by the ignition of an intimate mixture of the carbonate and See also:

• CARBON (symbol C, atomic weight 12)

carbon, and in small quantities by the ignition of the iodate . It is a greyish coloured solid, which combines very energetically with water to form the hydroxide, much See also:

• HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

heat being evolved during the See also:

• COMBINATION (Lat. combinare, to combine)

combination; on heating to redness in a current of oxygen it combines with the oxygen to form the dioxide, which at higher temperatures breaks up again into the monoxide and oxygen . Barium hydroxide, Ba(OH)2, is a white See also:

• POWDER (through O. Fr. puldre, modern poudre, from Lat. pulvis, pulveris, dust)

powder that can be obtained by slaking the monoxide with the requisite quantity of water, but it is usually made on the large See also:

• SCALE
• SCALE (1) A

scale by heating heavy spar with small See also:

• COAL

coal whereby a crude barium sulphide is obtained .

This sulphide is then heated in a current of moist carbon dioxide, barium carbonate being formed, BaS+H20+See also:

• CO2

CO2=BaCO3+H2S, and finally the carbonate is decomposed by a current of superheated See also:

• STEAM
• STEAM (0. Eng. steam, vapour, smoke, cf. Du. steam; the origin is unknown)

steam, BaCOa +H20 = Ba(OH)2+ CO2, leavingaresidue of the hydroxide . It is a white powder moderately soluble in See also:

• COLD (in O. Eng. cald and ceald, a word coming ultimately from a root cognate with the Lat. gelu, gelidus, and common in the Teutonic languages, which usually have two distinct forms for the substantive and the adjective, cf. Ger. Kolte, kalt, Dutch koude

cold water, readily soluble in hot water, the solution possessing an alkaline reaction and absorbing carbon dioxide readily . The solution, known as baryta-water, finds an extensive application in See also:

• PRACTICAL

practical See also:

• CHEMISTRY
• CHEMISTRY (formerly "chymistry"; Gr. xvµela; for derivation see ALCHEMY)

chemistry, being used in See also:

• GAS

gas-See also:

• ANALYSIS (Gr. avci and Meta, to break up into parts)

analysis for the determination of the amount of carbon dioxide in the See also:

• ATMOSPHERE (Gr. fir µ6r, vapour; orkaipa, a sphere)

atmosphere; and also being used in organic chemistry as a hydrolysing See also:

• AGENT (from Lat. agere, to act)

agent for the decompositionof complex ureides and substituted aceto-acetic See also:

• ESTERS

esters, while . E . See also:

• FISCHER
• FISCHER, EMIL (1852– )
• FISCHER, ERNST KUNO BERTHOLD (1824–1907)

Fischer has used it as a condensing agent in the preparation of a- and $-acrose from acrolein dibromide . A saturated solution of the hydroxide deposits on cooling a hydrated form Ba(OH)'2.8H20, as colourless quadratic prisms, which on exposure to air lose seven molecules of water of See also:

• CRYSTALLIZATION

crystallization . Barium dioxide, BaO2, can be prepared as shown above, or in the hydrated See also:

• CONDITION (Lat. condicio, from condicere, to agree upon, arrange; not connected with conditio, from condere, conditum, to put together)

condition by the addition of excess of barytawater to See also:

• HYDROGEN [symbol H, atomic weight x-oo8 (0=16)]

hydrogen peroxide solution, when it is precipitated in the crystalline condition as BaO2.8H2O . These crystals on heating to 130° C. lose the water of crystallization and leave a residue of the anhydrous peroxide . In the See also:

• BRIN, BENEDETTO (1833—1898)

Brin process for the manufacture of oxygen, barium dioxide is obtained as an intermediate product by heating barium monoxide with air under pressure . It is a See also:

• GREY, CHARLES GREY, 2ND EARL (1764-1845)
• GREY, HENRY GREY, 3RD EARL (1802-1894)
• GREY, LADY JANE (1537-1554)
• GREY, SIR EDWARD
• GREY, SIR GEORGE (1812–1898)

grey coloured powder which is readily decomposed by dilute acids with the See also:

• PRODUCTION (Lat. productionem, from producere, to pro-duce)

production of hydrogen peroxide . Barium chloride, BaCl2.2H2O, can be obtained by dissolving witherite in dilute hydrochloric acid, and also from heavy spar by ignition in a reverberatory See also:

• FURNACE

furnace with a mixture of coal, See also:

• LIMESTONE

limestone and See also:

• CALCIUM [symbol Ca, atomic weight 40.0 (o= x6)]

calcium chloride, the barium chloride being extracted from the fused See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass by water, leaving a residue of insoluble calcium sulphide . The chloride crystallizes in colourless rhombic tables of specific gravity 3•o and is readily soluble in water, but is almost insoluble in concentrated hydrochloric acid and in See also:

• ABSOLUTE (Lat. absolvere, to loose, set free)

absolute alcohol .

It can be obtained in the anhydrous condition by heating it gently to about 120° C . It has a See also:

• BITTER, KARL THEODORE FRANCIS (1867– )

bitter See also:

• TASTE (from Lat. taxare, to touch sharply; tangere, to touch)

taste and is a strong See also:

• POISON

poison . Barium bromide is prepared by saturating baryta-water or by decomposing barium carbonate with hydrobromic acid . It crystallizes as BaBr2.2H20 isomorphous with barium chloride . Barium bromate, Ba(Br03)2, can be prepared by the See also:

• ACTION

action of excess of See also:

• BROMINE (symbol Br, atomic weight 79-96)

bromine on barytawater, or by decomposing a boiling aqueous solution of too parts of See also:

• POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium bromate with a similar solution of 74 parts of crystallized barium chloride . It crystallizes in the See also:

• MONOCLINIC

monoclinic See also:

• SYSTEM

system,and separates from its aqueous solution as Ba(Br03)2•H20 . On heating, it begins to decompose at 26o-265° C . Barium chlorate, Ba(C103)2, is obtained by adding barium chloride to See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium chlorate solution; on concentration of the solution sodium chloride separates first, and then on further evaporation barium chlorate crystallizes out and can be purified by recrystallization . It can also be obtained by suspending barium carbonate in boiling water and passing in See also:

• CHLORINE (symbol Cl, atomic weight 35`46 (0=16)

chlorine . It crystallizes in mono-clinic prisms of See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition Ba(C103)2.H20, and begins to decompose on being heated to 25o° C . Barium iodate, Ba(I03)2, is obtained by the action of excess of iodic acid on hot See also:

• CAUSTIC (Gr. rcavvraubs, burning)

caustic barytaa solution or by adding sodium iodate to barium chloride solution . It crystallizes in monoclinic prisms of composition Ba(IOa)2•See also:

• H2O (combined)

H2O, and is only very sparingly soluble in cold water .

Barium See also:

• CARBIDE

carbide, BaC2, is prepared by a method similar to that in use for the preparation of calcium carbide (see See also:

• ACETYLENE

ACETYLENE) . L . Maquenne has also obtained it by distilling a mixture of barium amalgam and carbon in a stream of hydrogen . Barium sulphide, BaS, is obtained by passing sulphuretted hydrogen over heated barium monoxide, or better by See also:

• FUSION

fusion of the sulphate with a small coal . It is a white powder which is readily decomposed by water with the formation of the hydroxide and hydrosulphide . The See also:

• PHOSPHORESCENCE

phosphorescence of the sulphide obtained by heating the thiosulphate is much increased by adding See also:

• URANIUM [symbol U, atomic weight 238.5 (0=16)]

uranium, See also:

• BISMUTH

bismuth, or See also:

• THORIUM (symbol Th, atomic weight ,232.42 [0=16])

thorium before ignition (J. pr . Chem., 1go5, ii. p . 196) . 'Barium sulphate, BaSO4, is the most abundant of the naturally occurring barium compounds (see BARYTES) and can be obtained artificially by the addition of sulphuric acid or any soluble sulphate to a solution of a soluble barium salt, when it is precipitated as an amorphous white powder of specific gravity 4'5 . It is practically insoluble in water, and is only very slightly soluble in dilute acids; it is soluble to some extent, when freshly prepared, in hot concentrated sulphuric acid, and on cooling the solution, crystals of composition BaSO4•H2SO4 are deposited . It is used as a pigment under the name of " permanent white " or See also:

• BLANC, (JEAN JOSEPH CHARLES) LOUIS (1811-1882)
• BLANC, MONT

blanc fixe . Barium nitride, BasN2, is obtained as a brownish mass by passing nitrogen over heated barium amalgam .

It is decomposed by water with See also:

• EVOLUTION

evolution bf hydrogen, and on heating in a cur-See also:

• RENT

rent of carbonic See also:

• OXIDE

oxide forms barium See also:

• CYANIDE

cyanide (L . Maquenne) . Barium See also:

• AMIDE

amide, Ba(See also:

• NH2

NH2)2, is obtained from potassammonium and barium bromide . Barium nitrate, Ba(NO3)2, is prepared by dissolving either the carbonate or sulphide in dilute nitric acid, or by mixing hot saturated solutions of barium chloride and sodium nitrate . It crystallizes in octahedra, having a specific gravity of 3.2, and melts at 597° C . (T . Carnelley) .. It is decomposed by heat, and is largely used in pyrotechny for the preparation of See also:

• GREEN, A
• GREEN, ALEXANDER HENRY (1832—1896)
• GREEN, DUFF (1791—1875)
• GREEN, JOHN RICHARD (1837—1883)
• GREEN, MATTHEW (1696-1737)
• GREEN, THOMAS HILL (1836-1882)
• GREEN, VALENTINE (1739–1813)
• GREEN, WILLIAM HENRY (.1825–1900)

green See also:

• FIRE (in O. Eng. f j'r; the word is common to West German languages, cf. Dutch vuur, Ger. Feuer; the pre-Teutonic form is seen in Sanskrit pu, pavaka, and Gr. irup; the ultimate origin is usually taken to be a root meaning to purify, cf. Lat. purus)

fire . Barium carbonate, BaCO3, occurs rather widely distributed as witherite (q.v.), and may be prepared by the addition of barium chloride to a hot solution of ammonium carbonate, when it is precipitated as a dense white powder of specific gravity 4.3; almost insoluble in water . Barium and its salts can be readily detected by the yellowish-green See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour they give when moistened with hydrochloric acid and heated in the Bunsenflame, or by observation of their spectra, when two characteristic green lines are seen . In solution, barium salts may be detected by the immediate precipitate they give on the addition of calcium sulphate (this serves to distinguish barium salts from calcium salts), and by the yellow precipitate of barium chromate formed on the addition of potassium chromate . Barium is estimated quantitatively by See also:

• CONVERSION (Lat. conversio, from convertere, to turn or ,change)

conversion into the sulphate .

The atomic See also:

• WEIGHT

weight of the See also:

• ELEMENT (Lat. elementum)

element has been determined by C . See also:

• MARIGNAC, JEAN CHARLES GALISSARD DE (1817-1894)

Marignac by the conversion of barium chloride into barium sulphate, and also by a determination of the amount of silver required to precipitate exactly a known weight of the chloride; the mean value obtained being 136.84; T . W . See also:

• RICHARDS, ALFRED BATE (182o-1876)
• RICHARDS, HENRY BRINLEY (1819-1865)
• RICHARDS, WILLIAM TROST (1833-1905)

Richards (Zeit. anorg . Chem., 1893, 6, p . 89), by determining the See also:

• EQUIVALENT

equivalent of barium chloride and bromide to silver, obtained the value 137•.44 . For the relation of barium to See also:

• RADIUM (from Lat. radius, ray)

radium, see See also:

• RADIOACTIVITY

RADIOACTIVITY .