See also:

• GALLIUM (symbol Ga; atomic weight 69.9)

GALLIUM (See also:

• SYMBOL (Gr. o-uµ(3oXov, a sign)

symbol Ga; atomic See also:

• WEIGHT

weight 69.9)  , one of the metallic chemical elements . It was discovered in 1875 through its spectrum, in a specimen of See also:

• ZINC

zinc See also:

• BLENDE, or SPHALERITE

blende by Lecoq de Boisbaudran (Comptes rendus, 1895, 81, p . 493, and following years) . The See also:

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

chief chemical and See also:

• PHYSICAL

physical properties of See also:

• GALLIUM (symbol Ga; atomic weight 69.9)

gallium had been predicted many years before by D . Mendeleeff (c . 1869) from a See also:

• CONSIDERATION (from Lat. considerare, to look at closely, examine, generally taken to be from con-, and the base seen in sidus, sideris, a star, the word being supposed to be originally an astrological or astronomical term)

consideration of the properties of See also:

• ALUMINIUM (symbol Al; atomic weight 27.0)

aluminium, See also:

• INDIUM (symbol In, atomic weight 114.8)

indium and zinc (see See also:

• ELEMENT (Lat. elementum)

ELEMENT) . 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 obtained from zinc blende (which only contains it in very small quantity) by dissolving the See also:

• MINERAL

mineral in an See also:

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

acid, andprecipitating the gallium by metallic zinc . The precipitate is dissolved in hydrochloric acid and See also:

• FOREIGN

foreign metals are removed by sulphuretted See also:

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

hydrogen; the residual liquid being then fraction-ally precipitated by See also:

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

sodium carbonate, which throws out the gallium before the zinc . This precipitate is converted into gallium sulphate and finally into a pure specimen of the See also:

• OXIDE

oxide, from which the metal is obtained by the See also:

• ELECTROLYSIS (formed from Gr. Xbety, to loosen)

electrolysis of an alkaline See also:

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

solution . Gallium crystallizes in greyish-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 octahedra which melt at 30.1'5° C. to a silvery-white liquid . It is very hard and but slightly malleable and flexible, although in thin plates it may be See also:

• BENT
• BENT (E1. BENI)
• BENT, JAMES THEODORE (1852–1897)

bent several times without breaking . The specific gravity of the solid See also:

• FORM (Lat. forma)

form is 5.956 (24.50 C.), of the liquid 6•o69, whilst the specific heats of the two varieties are, for the solid form o•079 (12-23° C.) and for the liquid 0•082 (106-119°) [M .

See also:

• BERTHELOT, MARCELLIN PIERRE EUGENE (1827–1907)

Berthelot, Comptes rendus, 1878, 86, p . 786] . It is not appreciably volatilized 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 . See also:

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

Chlorine acts on it readily in the 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, See also:

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

bromine not so easily, and See also:

• IODINE (symbol I, atomic weight '26.92)

iodine only when the mixture is heated . The atomic See also:

• WEIGHT

weight of gallium has been determined by Lecoq de Boisbaudran by ignition of gallium ammonium See also:

• ALUM

alum, and also by L . See also:

• MEYER, CHRISTIAN ERICH HERMANN VON (18or-1869)
• MEYER, HEINRICH AUGUST WILHELM (1800-1873)
• MEYER, JULIUS LOTHAR (183o-1895)
• MEYER, KONRAD FERDINAND (1825-1898)
• MEYER, VICTOR (1848-1897)
• MEYER, [MARIE] PAUL HYACINTHE (184o- )

Meyer and K . Seubert . Gallium oxide Ga203 is obtained when the nitrate is heated, or by solution of the metal in nitric acid and ignition of the nitrate . It forms a white friable See also:

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

mass which after ignition is insoluble in acids . On See also:

• HEATING

heating to redness in a stream of hydrogen it forms a bluish mass which is probably a See also:

• LOWER

lower oxide of See also:

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

composition See also:

• GAO

GaO . Gallium forms colourless salts, which in neutral dilute aqueous solutions are converted on heating into basic salts . The gallium salts are precipitated by alkaline See also:

• CARBONATES

carbonates and by See also:

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

barium carbonate, but not by sulphuretted hydrogen unless in acetic acid solution .

See also:

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

Potassium ferrocyanide gives a precipitate even in very dilute solution . In neutral solutions, zinc gives a precipitate of gallium oxide . By heating gallium in a regulated stream of chlorine the dichloride GaCl2 is obtained as a crystalline mass, which melts at 164° C. and readily decomposes on exposure to moist See also:

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

air . The tichloride GaCla is similarly formed when the metal is heated in a rapid stream of chlorine, and may be purified by See also:

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

distillation in an See also:

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

atmosphere of See also:

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

nitrogen . It forms very deliquescent See also:

• LONG, GEORGE (1800-1879)
• LONG, JOHN DAVIS (1838– )

long white needles melting at 75.5 C. and boiling at 215-220° C . The bromide, iodide and sulphate are known, as is also gallium ammonium alum . Gallium is best detected by means of its spark spectrum, which gives two See also:

• VIOLET

violet lines of See also:

• WAVE

wave length 4171 and 4031 .