or a dispensary of oracles
([Greek: chresmographia] mentioned in the inscriptions) and a treasury;
two flights of stairs called "labyrinths" in the inscriptions, led up to
these chambers; (4) the pylon and staircase at the west; (5) the frieze
of Medusa heads and foliage. Two outer columns are still erect on the
north-east flank, carrying their entablature, and one of the inner order
stands on the south-west. The fact that the temple was never finished is
evident from the state in which some bases still remain at the west.
There were probably no pedimental sculptures. A sacred way led from the
temple to the sea at Panormus, which was flanked with rows of archaic
statues, ten of which were excavated and sent to the British Museum in
1858 by C. T. Newton. Fragments of architectural monuments, which once
adorned this road, have also been found. Modern Hieronta is a large and
growing Greek village, the only settlement within a radius of several
miles. Its harbour is Kovella, distant about 2-1/2 m., and on the N. of
the promontory.

See Dilettanti Society, _Ionian Antiquities_, ii. (1821); C. T.
Newton, _Hist. of Discoveries_, &c. (1862) and _Travels in the
Levant_, ii. (1865); O. Rayet and A. Thomas, _Milet et le Golfe
Latmique_ (1877); E. Pontremoli and B. Haussoullier, _Didymes_ (1904).
(D. G. H.)

DIDYMIUM (from the Gr. [Greek: didymos], twin), the name given to the
supposed element isolated by C. G. Mosander from cerite (1839-1841). In
1879, however, Lecoq de Boisbaudran showed that Mosander's "didymium"
contained samarium; while the residual "didymium," after removal of
samarium, was split by Auer v. Welsbach (_Monats. f. Chemie_, 1885, 6,
477) into two components (known respectively as neodymium and
praseodymium) by repeated fractional crystallization of the double
nitrate of ammonium and didymium in nitric acid. _Neodymium_ (Nd) forms
the chief portion of the old "didymium." Its salts are reddish violet in
colour, and give a characteristic absorption spectrum. It forms oxides
of composition Nd2O3 and Nd2O5, the latter being obtained by ignition of
the nitrate (B. Brauner). The atomic weight of neodymium is 143.6 (B.
Brauner, _Proc. Chem. Soc._, 1897-1898, p. 70). _Praseodymium_ (Pr)
forms oxides of composition Pr2O3, Pr2O5, xH2O (B. Brauner), and Pr4O7.
The peroxide, Pr4O7, forms a dark brown powder, and is obtained by
ignition of the oxalate or nitrate. The sesquioxide, Pr2O3, is obtained
as a