See also:

• ERBIUM (symbol, Er; atomic weight, 165-166)

ERBIUM (See also:

• SYMBOL (Gr. o-uµ(3oXov, a sign)

symbol, Er; atomic See also:

• WEIGHT

weight, 165-166)  , one of the metals of the rare earths . The first of the rare See also:

• EARTH
• EARTH (a word common to Teutonic languages, cf. Ger. Erde, Dutch aarde, Swed. and Dan. jord; outside Teutonic it appears only in the Gr. 'pq'e, on the ground; it has been connected by some etymologists with the Aryan root ar-, to plough, which is seen in
• EARTH, FIGURE OF
• EARTH, FIGURE OF THE

earth minerals was discovered in 1794 by J . Gadolin and was named gadolinite from its discoverer . In 1797 Ekeberg showed that gadolinite contained another rare earth, which was given the name yttria . Yttria is an exceedingly complex mixture, which has been decomposed, yielding as an intermediate product terbia . This latter substance in its turn has been split by J . L . Soret, P . T . Cleve, Lecoq de Boisbaudran and others into erbia, holmia, thulia and dysprosia, but it is still doubtful whether any one of these four splitting products is a single substance . The rare earth metals are found in the minerals gadolinite, samarskite, fergusonite, euxenite and cerite . They are separated from the minerals by converting them into oxalates, which by ignition give the corresponding oxides .

The oxides are then converted into 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 sulphates which are separated from each other by repeated fractional See also:

• CRYSTALLIZATION

crystallization or by fractional precipitation with See also:

• AMMONIA (NH3)

ammonia or some other See also:

• BASE

base . See also:

• ERBIUM (symbol, Er; atomic weight, 165-166)

Erbium forms See also:

• ROSE
• ROSE (Rosa)
• ROSE, GEORGE (1744-1818)
• ROSE, HUGH JAMES (1795—1838)
• ROSE, WILLIAM STEWART (1775-1843)

rose-coloured salts and a rose-coloured See also:

• OXIDE

oxide . The oxide dissolves slowly in acids; it is not reduced by See also:

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

hydrogen and is infusible . The salts show a characteristic absorption spectrum . See J . F . See also:

• BAHR

Bahr and R . See also:

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

Bunsen (See also:

• ANN

Ann., 1866, 137, p . I) ; A. v . Weis, See also:

• BACH, JOHANN SEBASTIAN (1685–1750)
• BACH, KARL PHILIPP EMANUEL (1714-1788)

bach (Monats., 1883, 4, p . 641; 1884, 5, p . 508; 1885, 6, p .

477); P . T . Cleve (Comptes rendus, 1879, 89, p . 478; 188o, 91, pp . 328, 381; 1882, 95, p . 1225; See also:

• BULL
• BULL, GEORGE (1634–1710)
• BULL, JOHN (c. 1562–1628)
• BULL, OLE BORNEMANN (18ro-188o)

Bull. de la See also:

• SOC

soc. chim., 1874, 21, p . 196; 1883, 39, p . 287) ; C . See also:

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

Marignac (Ann.Chim. phys., 1849 [3] 27, p . 226) ; B . Brauner (Monats., 1882, 3, p . 13); W .

See also:

• CROOKES, SIR WILLIAM (1832– )

Crookes (Prot . See also:

• ROY, WILLIAM (1726-1790)

Roy . Soc., 1886, 40, p . 502) ; Lecoq de Boisbaudran (Comptes rendus, 1886, 102, p . 1005) ; A . Bettendorf (Ann., 1892, 270, p . 376) ; M . Muthmann (Ber., 1898, 31, p . 1718; 1900, 33, p . 42) ; G . Kriiss (Zeit. f. anorg . Chem., 1893, 3, p. io8) .