atomic See also:

• WEIGHT

weight 184.o See also:

• atomic weight 184.o TUNGSTEN [symbol W (0=16)]

TUNGSTEN [See also:

• SYMBOL (Gr. o-uµ(3oXov, a sign)

symbol W (0=16)]  , a metallic chemical See also:

• ELEMENT (Lat. elementum)

element found in the minerals wolfram, an See also:

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

iron and See also:

• MANGANESE (symbol Mn; atomic weight, 54.93 (0=16)], a metallic chemical element. Its dioxide (pyrolusite)

manganese tungstate, See also:

• SCHEELITE

scheelite, a See also:

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

calcium tungstate, stolzite, a See also:

• LEAD
• LEAD (pronounced iced)

lead tungstate, and in some rarer minerals . Its presence in scheelite was detected by See also:

• SCHEELE, KARL WILHELM (1742-1786)

Scheele and See also:

• BERGMAN, TORBERN OLOF (1735-1784)

Bergman in 1781, and in 1783 Juan, Jose and d'Elhuyar showed the same substance occurred in wolfram; they also obtained 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 . See also:

• TUNGSTEN [symbol W, atomic weight 184.o (0=16)]

Tungsten may be prepared from wolfram by See also:

• HEATING

heating the powdered ore with See also:

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

sodium carbonate, extracting the sodium carbonate with See also:

• WATER

water, filtering and adding an See also:

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

acid to precipitate tungstic acid, 112WO4 . This is washed and dried and the See also:

• OXIDE

oxide so obtained reduced to the metal by heating with See also:

• CARBON (symbol C, atomic weight 12)

carbon to a high temperature (Hadfield, Journ . Iron and See also:

• STEEL, FLORA ANNIE (1847– )

Steel Inst., 1903, ii . 38) . On a small See also:

• SCALE
• SCALE (1) A

scale it is obtained by reducing the trioxide in a current of See also:

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

hydrogen, or the chloride by sodium vapour, or the oxide with carbon in the electric See also:

• FURNACE

furnace; in the last See also:

• CASE
• CASE, JOHN (d. 1600)

case the product is porous and can be welded like iron . In the See also:

• FORM (Lat. forma)

form of a See also:

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

powder, it is obtained by reducing the oxide with See also:

• ZINC

zinc and extracting with soda, or by dissolving out the manganese from its See also:

• ALLOYS (through the Fr. aloyer, from Lat. alligare, to combine)

alloys with tungsten . The metal may be used uncombined, but large quantities of ferrotungsten are made in the electric furnace; other alloys are prepared by acting on a mixture of the oxides with See also:

• ALUMINIUM (symbol Al; atomic weight 27.0)

aluminium . Tungsten has been applied in the manufacture of filament electric lamps . The metal has a crystalline structure, and melts at about 2800° . The powdered metal See also:

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

burns at a red 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 to form the trioxide; it is very slowly attacked by moist See also:

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

air .

It combines with See also:

• FLUORINE (symbol F, atomic weight 19)

fluorine with incandescence at See also:

• ORDINARY (med. Lat. ordinarius, Fr. ordinaire)

ordinary temperatures, and with See also:

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

chlorine at 250—300°; carbon, See also:

• SILICON [symbol Si, atomic weight 28.3 (0= 16)]

silicon, and See also:

• BORON (symbol B, atomic weight I I)

boron, when heated with it in the electric furnace, give crystals harder than the See also:

• RUBY (Lat. rubeus, red)

ruby . It is soluble in a mixture of nitricand hydrofluoric acids, and the powdered metal, in aqua regia, but slowly attacked by sulphuric, hydrochloric and hydrofluoric acids separately; it is also soluble in boiling potash See also:

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

solution, giving a tunstate and hydrogen . Tungsten dioxide, W02, formed on reducing the trioxide by hydro- gen at a red heat or a mixture of the trioxide and hydrochloric acid with zinc, or by decomposing the tetrachloride with water, is a See also:

• BROWN
• BROWN, CHARLES BROCKDEN (1771-181o)
• BROWN, FORD MADOX (1821-1893)
• BROWN, FRANCIS (1849- )
• BROWN, GEORGE (1818-188o)
• BROWN, HENRY KIRKE (1814-1886)
• BROWN, JACOB (1775–1828)
• BROWN, JOHN (1715–1766)
• BROWN, JOHN (1722-1787)
• BROWN, JOHN (1735–1788)
• BROWN, JOHN (1784–1858)
• BROWN, JOHN (1800-1859)
• BROWN, JOHN (1810—1882)
• BROWN, JOHN GEORGE (1831— )
• BROWN, ROBERT (1773-1858)
• BROWN, SAMUEL MORISON (1817—1856)
• BROWN, SIR GEORGE (1790-1865)
• BROWN, SIR JOHN (1816-1896)
• BROWN, SIR WILLIAM, BART
• BROWN, THOMAS (1663-1704)
• BROWN, THOMAS (1778-1820)
• BROWN, THOMAS EDWARD (1830-1897)
• BROWN, WILLIAM LAURENCE (1755–1830)

brown strongly pyrophoric powder, which must be cooled in hydrogen before being brought into contact with air . It is slightly soluble in hydrochloric and sulphuric acids, giving See also:

• PURPLE

purple solutions . It dissolves in potash, giving See also:

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

potassium tungstate and hydrogen, and is readily oxidized to the trioxide . Tungsten trioxide, WO3, occurs in nature as wolframine, a yellow See also:

• MINERAL

mineral found in See also:

• CUMBERLAND
• CUMBERLAND, DUKES AND EARLS OF
• CUMBERLAND, RICHARD (1632-1718)
• CUMBERLAND, RICHARD (1732-1811)
• CUMBERLAND, WILLIAM AUGUSTUS

Cumberland, See also:

• LIMOGES

Limoges, See also:

• CONNECTICUT

Connecticut and in See also:

• NORTH
• NORTH, BARONS
• NORTH, MARIANNE (1830—1890)
• NORTH, ROGER (1653-1734)
• NORTH, SIR THOMAS (1535?-16o1?)

North Carolina . It is prepared as shown above, or by other methods . It is a See also:

• CANARY
• CANARY (Serinus canarius)

canary-yellow powder, which becomes a dark See also:

• ORANGE
• ORANGE (Citrus Aurantium)
• ORANGE, HOUSE OF

orange on heating; the See also:

• ORIGINAL

original See also:

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

colour is regained on cooling . On exposure to See also:

• LIGHT

light it assumes a greenish tinge . A crystalline form was obtained by Debray as See also:

• OLIVE (Olea europaea)

olive-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 prisms by igniting a mixture of sodium tungstate and carbonate in a current of hydrochloric acid See also:

• GAS

gas, and by Nordenskjold by heating hydrated tungstic acid with See also:

• BORAX (sodium pyroborate or sodium biborate)

borax . Partial reduction of tungsten trioxide gives See also:

• BLUE (common in different forms to most European languages)

blue or purple-red products which are intermediate in See also:

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

composition between the dioxide and trioxide . Tungsten trioxide forms two acids, tungstic acid, H2WO4, and metatungstic acid, H2W4O13; it also gives origin to several See also:

• SERIES (a Latin word from serere, to join)

series of salts, to which the acids corresponding are unknown .

Thus we have salts of the following types M20(W03),,, where n=1, 2, 3, 4, 5, 6, 7, 8, and also (M20),,,(W03),,, where in, n:=2, 5; 3, 7; 4, 3; 5, 12; M See also:

• STANDING

standing for a monovalent metal . The (M20)5(W03)12 or M10W12041 salts are called paratungstates . Tungstic acid, HZW04, is obtained as H2WO4•See also:

• H2O (combined)

H2O by precipitating a tungstate with 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 acid; this substance has a See also:

• BITTER, KARL THEODORE FRANCIS (1867– )

bitter See also:

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

taste and its aqueous solution reddens See also:

• LITMUS (apparently a corruption of lacmus, Dutch lacmoes, lac, lac, and moes, pulp, due to association with " lit," an obsolete word for dye, colour; the Ger. equivalent is Lac/emus, Fr tournesol)

litmus . By using hot acid the yellow anhydrous tungstic acid is precipitated, which is insoluble in water and in all acids except hydrofluoric . It may be obtained in a flocculent form by exposing the hexachloride to moist air . Metatungstic acid, H2W4O13.7H20, is obtained by decomposing the See also:

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

barium 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 with sulphuric acid or the lead salt with hydrochloric acid . It forms yellow octahedra, which become anhydrous at 1o0°, and are converted into the trioxide on ignition . It is readily soluble in water, and on boiling the aqueous solution a 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:

• HYDRATE

hydrate is first deposited which after a See also:

• TIME (0. Eng. Lima, cf. Icel. timi, Swed. timme, hour, Dan. time; from the root also seen in " tide," properly the time of between the flow and ebb of the sea, cf. O. Eng. getidan, to happen, " even-tide," &c.; it is not directly related to Lat. tempus)
• TIME, MEASUREMENT OF
• TIME, STANDARD

time is converted into the trioxide . See also:

• GRAHAM, SIR GERALD (1831–1899)
• GRAHAM, SIR JAMES ROBERT GEORGE
• GRAHAM, SYLVESTER (1794-1851)
• GRAHAM, THOMAS (1805-1869)

Graham obtained a colloidal tungstic acid by dialysing a dilute solution of sodium tungstate and its See also:

• EQUIVALENT

equivalent of hydrochloric acid ; on concentrating in a vacuum a gummy product is obtained, which still remains soluble after heating to 200 , but it is converted into the trioxide on heating to redness . When moistened it becomes adhesive . The solution has a bitter taste and does not gelatinize, even under the See also:

• INFLUENCE (Late Lat. influentia, from influere, to flow in)

influence of boiling acids . Of the salts, the normal tungstates are insoluble in water with the exception of the alkaline tungstates; they are usually amorphous, but some can be obtained in the crystalline form .

The metatungstates of the alkalis are obtained by boiling normal tungstates with tungstic acid until the addition of hydrochloric acid to the filtrate gives no precipitate . The most important tungstate is the so-called tungstate of soda, which is sodium paratungstate, NaioWi2041.28H2O . This salt is obtained by roasting wolfram with sodium carbonate, lixiviating, neutralizing the boiling filtrate with hydrochloric acid and crystallizing at ordinary temperatures . The salt forms large See also:

• MONOCLINIC

monoclinic prisms; molecules containing 25 and 21 H2O See also:

• SEPARATE

separate from solutions crystallized at higher temperatures . The salt is used as a See also:

• MORDANT

mordant in See also:

• DYEING (0. Eng. dedgian, dealt ; Mid. Eng. deyen)

dyeing and See also:

• CALICO

calico See also:

• PRINTING (from Lat. imprimere, O. Fr. empreindre)

printing, and also for making textiles non-inflammable . Several other sodium tungstates are known, as well as potassium and ammonium tungstates . Many salts also occur in the mineral See also:

• KINGDOM

kingdom: for example, scheelite is CaWO4, stolzite is PbWO4, farberite is FeWO4, wolfram is (Fe,Mn)WO4, whilst hiibnerite is MnWO4 . By partial reduction of the tungstates under certain conditions products are obtained which are insoluble in acids and alkalis and See also:

• PRESENT

present a See also:

• BRONZE

bronze-like See also:

• APPEARANCE (from Lat. apparere, to appear)

appearance which earned for them the name of tungsten bronzes . The sodium See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound was first obtained by See also:

• WOHLER, FRIEDRICH (1800-1882)

Wohler on reducing sodium tungstate with hydrogen; See also:

• COAL

coal-gas, zinc, iron or See also:

• TIN (Lat.- stannum, whence the chemical symbol " Sn "; atomic weight =117.6, 0=16)

tin also effect the reduction . It forms See also:

• GOLDEN

golden cubes which are unattacked by alkalis or by any acid except hydrofluoric . It appears to be a mixture of which the components vary with the materials and methods used in its See also:

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

production (Philipp, Ber., 1882, 15, p . 499) .

A blue bronze, Na2W5O15, forming dark blue cubes with a red reflex, is obtained by electrolysing fused sodium paratungstate; a purple-red variety, Na2W3O9, and a reddish yellow form result when sodium carbonate and sodium tungstate are heated respectively with tungsten trioxide and tinfoil . Similar potassium tungsten bronzes are known . Tungstic acid closely resembles molybdic acid in combining with phosphoric, arsenious, See also:

• ARSENIC (symbol As, atomic weight 75.0)

arsenic, boric, vanadic and silicic acids to form highly complex acids of which a See also:

• GREAT

great many salts exist . Of the phosphotungstic acids the most important is phosphoduodecitungstic acid, H3PWi204o•nH2O, obtained in quadratic pyramids by crystallizing mixed solutions of orthophosphoric and metatungstic acids . Two sodium salts, viz . NasHPW13Ogo•nHsO and Na3PWisO4o•nH2O, are obtained by heating sodium hydrogen phosphate with a tungstate . The most important silicotungstic acids are silicodecitungstic acid HsW1oSiO3s 3H2O, tungstosilicic acid, H8W,2SiO42.2oH2O, and silicoduodecitungstic or silicotungstic acid, HsW1iSiO42.29H2O . On boiling gelatinous See also:

• SILICA

silica with ammonium polytungstate and evaporating with the occasional addition of See also:

• AMMONIA (NH3)

ammonia, ammonium sihcodecitungstate is obtained as See also:

• SHORT, FRANCIS JOB (1857– )

short rhombic prisms . On adding See also:

• SILVER

silver nitrate and decomposing the precipitated silver salt with hydrochloric acid, a solution is obtained which on evaporation in a vacuum gives the See also:

• FREE

free acid as a See also:

• GLASS
• GLASS (O.E. glees, cf. Ger. Glas, perhaps derived from an old Teutonic root gla-, a variant of glo-, having the general sense of shining, cf. " glare," " glow ")
• GLASS, STAINED

glass, See also:

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

mass . If this be dissolved in water and the solution concentrated, some silicic acid separates and the filtrate deposits triclinic prisms of tungstosilicic acid . Silicotungstic acid is obtained as quadratic pyramids from its mercurous salt which is prepared from mercurous nitrate and the salt formed on boiling gelatinous silicic acid with a polytungstate of an See also:

• ALKALI

alkali metal . Pertungstic Acid, HWO4.—The sodium salt, NaWO4•H2O, is obtained by evaporating in a vacuum the product of boiling a solution of sodium paratungstate with hydrogen peroxide .

Its solution liberates chlorine from hydrochloric acid and See also:

• IODINE (symbol I, atomic weight '26.92)

iodine from potassium iodide . Halogen Compounds.—Although the trioxide is soluble in hydrofluoric acid, evaporation of the solution leads to the recovery of the oxide unchanged . A See also:

• DOUBLE
• DOUBLE (from the Mid. Eng. duble, the form which gives the present pronunciation, through the Old Er. duble, from Lat. duplus, twice as much)

double salt of the oxyfluoride, viz . 2KF•WO1F2•H2O, is obtained as crystalline scales by dissolving normal potassium tungstate in hydrofluoric acid and adding potassium hydroxide till a permanent precipitate is just formed . Other oxyfluorides are known . The hexafluoride, WF6, is a very active gaseous compound, which attacks glass and metals, obtained from tungsten hexachloride and hydrofluoric acid (See also:

• RUFF

Ruff and Eisner, Per., 1905, 38, p . 742) . Oxyfluorides of the formulae WOF4 and WO2F2 are also known . Tungsten forms four chlorides, viz . WCl2, WCI4, WCI6, WCI6 . The dichloride, WCl2, is an amorphous 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 powder obtained by reducing the hexachloride at a high temperature in hydrogen, or, better, by heating the tetrachloride in a current of carbon dioxide . It changes on exposure to air and dissolves slightly in water to give a brown solution, the insoluble portion gradually being converted into an oxide with See also:

• EVOLUTION

evolution of hydrogen .

The tetrachloride, WCI4, is obtained by partial reduction of the higher chlorides with hydrogen; a mixture of the pentaand hexes-chloride is distilled in a stream of hydrogen or carbon dioxide, and the pentachloride which volatilizes returned to the See also:

• FLASK

flask several times . This gives the tetrachloride as a greyish-brown crystalline powder . It is very hygroscopic and with cold water gives the oxide and hydrochloric acid . On heating it gives the di- and penta-chlorides . At a high temperature hydrogen reduces it to the metal partly in the form of a See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black pyrophoric powder . The pentachloride, WCI6, is obtained as a product in the preparation of the tetrachloride . It forms black lustrous crystals, or when quickly condensed, a dark green crystalline powder . It melts at 248° and boils at 275.60; the vapour See also:

• DENSITY (Lat. densus, thick)

density corresponds to the above See also:

• FORMULA
• FORMULA (Lat. diminutive of forma, shape, pattern, &c., especially used of rules of judicial procedure)

formula . It is more hygroscopic than the tetrachloride; and when treated with much water the bulk is-at once decomposed into the blue oxide and hydrochloric acid, but an olive-green solution is also produced . The hexachloride, WCI6, is obtained by heating the metal in a current of dry chlorine in the See also:

• ABSENCE (Lat. absentia)

absence of See also:

• OXYGEN (symbol 0, atomic weight 16)

oxygen or moisture, otherwise some oxychloride is formed; a sublimate of dark See also:

• VIOLET

violet crystals appear at first, but as the hexachloride increases in quantity it collects as a very dark red liquid . When perfectly pure, the hexachloride is See also:

• STABLE

stable even in moist air, but the presence of an oxychloride brings about energetic decomposition; similarly water has no See also:

• ACTION

action on the pure compound, but a trace of the oxychloride occasions sudden decomposition into a greenish oxide and hydrochloric acid . It melts at 275° See also:

• HAND
• HAND (a word common to Teutonic languages; cf. Ger. Hand, Goth. handus)
• HAND, FERDINAND GOTTHELF (1786-185r)

hand boils at 346.7° (759.5 mm.) .

Vapour density determinations indicate that See also:

• DISSOCIATION

dissociation occurs when the vapour is heated above the boiling point . Several oxychlorides are known . The monoxychloride, WOC14, is obtained as red acicular crystals by heating the oxide or dioxychloride in a current of the vapour of the hexachloride, or from the trioxide and See also:

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

phosphorus pentachloride . It melts at 210.4° and moils at 227.5 forming a red vapour . Moist air brings about the immediate formation of a yellowish crust of tungstic acid . The dioxychloride, WO2Cl2, is obtained as a light See also:

• LEMON
• LEMON, MARK (1809-1870)

lemon-yellow sublimate on passing chlorine over the brown oxide . It is unaffected by moist air or cold water, and even when boiled with water the decomposition is incomplete . Tungsten combines directly with See also:

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

bromine to give, when the bromine is in excess, the penta- and not a hexabromide . This substance forms crystals resembling iodine, which melt at 276° and See also:

• BOIL

boil at 333° . It slowly evolves bromine on standing, and is at once decomposed by water into the blue oxide and hydrobromic acid . The dibromide, WBr2, is a non-volatile bluish-black powder obtained by reducing the pentabromide with hydrogen . By passing bromine vapour over red-hot tungsten dioxide a mixture of WO2Br2 and WOBr4 is obtained, from which the latter can be removed by gently heating when it volatilizes .

The dioxybromide forms light red crystals or a yellow powder; it volatilizes at a red heat, and is not acted upon by water . The monoxybromideforms brownish-black needles, which melt at 277° and boil at 327-5; it is decomposed by water . The di-iodide is obtained as green metallic scales on passing iodine over red-hot tungsten . Tungsten disulphide, WS2, is obtained as soft black acicular crystals by the action of See also:

• SULPHUR

sulphur, sulphuretted hydrogen or carbon bisulphide on tungsten . The trisulphide, WS3, is obtained by dissolving the trioxide in ammonium sulphide or by passing sulphuretted hydrogen into a solution of a tungstate and precipitating by an acid in both cases . When dry it is a black mass which yields a See also:

• LIVER (O. Eng. lifer; cf. cognate forms, Dutch lever, Ger. Leber, Swed. lefver, &c.; the O. H. Ger. forms are libara, lipora, &c.; the Teut. word has been connected with Gr. i'prap and Lat. jecur)

liver-coloured powder . It is sparingly soluble in cold water, but is easily dissolved by potassium carbonate or ammonia . By dissolving it in a hydrosulphide a sulphotungstate is produced ; these salts can also be obtained by passing sulphuretted hydrogen into a solution of a tungstate . A nitride, W2N3, is obtained as a black powder by acting with ammonia on the oxytetrachloride or hexachloride ; it is insoluble in sodium hydroxide, nitric and dilute sulphuric acids; strong sulphuric acid, however, gives ammonia and tungstic acids . Ammonia does not react with tungsten or the dioxide, but with trioxide at a red heat a substance of the formula W5H6N3O5 is obtained, which is insoluble in acids and alkalis and on ignition decomposes, evolving See also:

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

nitrogen, hydrogen and ammonia . Phosphorus combines directly with the metal to form W3P4; another phosphide, W2P, results on igniting a mixture of phosphorus pentoxide and tungsten trioxide . The atomic See also:

• WEIGHT

weight has been determined by many investigators ; the See also:

• CHIEF (from Fr. chef, head, Lat. caput)

chief methods employed being the See also:

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

analysis and See also:

• SYNTHESIS (Gr. a6vOeacs, from avvrcBivac, to put together)

synthesis of the trioxide and the analysis of the hexachloride .

The former was employed by Pennington and See also:

• SMITH
• SMITH, ADAM (1723–1790)
• SMITH, ALEXANDER (183o-1867)
• SMITH, ANDREW JACKSON (1815-1897)
• SMITH, CHARLES EMORY (1842–1908)
• SMITH, CHARLES FERGUSON (1807–1862)
• SMITH, CHARLOTTE (1749-1806)
• SMITH, COLVIN (1795—1875)
• SMITH, EDMUND KIRBY (1824-1893)
• SMITH, G
• SMITH, GEORGE (1789-1846)
• SMITH, GEORGE (184o-1876)
• SMITH, GEORGE ADAM (1856- )
• SMITH, GERRIT (1797–1874)
• SMITH, GOLDWIN (1823-191o)
• SMITH, HENRY BOYNTON (1815-1877)
• SMITH, HENRY JOHN STEPHEN (1826-1883)
• SMITH, HENRY PRESERVED (1847– )
• SMITH, JAMES (1775–1839)
• SMITH, JOHN (1579-1631)
• SMITH, JOHN RAPHAEL (1752–1812)
• SMITH, JOSEPH, JR
• SMITH, MORGAN LEWIS (1822–1874)
• SMITH, RICHARD BAIRD (1818-1861)
• SMITH, ROBERT (1689-1768)
• SMITH, SIR HENRY GEORGE WAKELYN
• SMITH, SIR THOMAS (1513-1577)
• SMITH, SIR WILLIAM (1813-1893)
• SMITH, SIR WILLIAM SIDNEY (1764-1840)
• SMITH, SYDNEY (1771-1845)
• SMITH, THOMAS SOUTHWOOD (1788-1861)
• SMITH, WILLIAM (1769-1839)
• SMITH, WILLIAM (c. 1730-1819)
• SMITH, WILLIAM (fl. 1596)
• SMITH, WILLIAM FARRAR (1824—1903)
• SMITH, WILLIAM HENRY (1808—1872)
• SMITH, WILLIAM HENRY (1825—1891)
• SMITH, WILLIAM ROBERTSON (1846-'894)

Smith and Desi (Zeit. anorg . Chem., 1895, 8, pp . 198, 205) who obtained the value 183.42 .