d, probably in
712, a Roman and Armenian army laid siege to Archaeopolis. On the
approach of a Saracen force they retired, but a small plundering
detachment was cut off. Ultimately Leo joined this band and aided by the
Apsilian chief Marinus escaped with them to the coast.

From the beginning of the 14th to the end of the 17th century the
district under the name Mingrelia (q.v.) was governed by an independent
dynasty, the Dadians, which was succeeded by a semi-independent dynasty,
the Chikovans, who by 1838 had submitted to Russia, though they retained
a nominal sovereignty. In 1866 the district was finally annexed by
Russia.

For the kings see Stokvis, _Manuel d'histoire_, i. 83. (J. M. M.)

COLCOTHAR (adapted in Romanic languages from Arabic _golgotar_, which
was probably a corruption of the Gr. [Greek: chalkanthos], from [Greek:
chalkos], copper, [Greek: anthos], flower, i.e. copper sulphate), a name
given to the brownish-red ferric oxide formed in the preparation of
fuming sulphuric (Nordhausen) acid by distilling ferrous sulphate. It is
used as a polishing powder, forming the rouge of jewellers, and as the
pigment Indian red. It is also known as _Crocus Martis_.

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. _Kalte_, _kalt_, Dutch _koude_, _koud_),
subjectively the sensation which is excited by contact with a substance
whose temperature is lower than the normal; objectively a quality or
condition of material bodies which gives rise to that sensation. Whether
cold, in the objective sense, was to be regarded as a positive quality
or merely as absence of heat was long a debated question. Thus Robert
Boyle, who does not commit himself definitely to either view, says, in
his _New Experiments and Observations touching Cold_, that "the dispute
which is the _primum frigidum_ is very well known among naturalists,
some contending for the earth, others for water, others for the air, and
some of the moderns for nitre, but all seeming to agree that there is
some body or other that is of its own nature supremely cold and by
participation of which all other bodies obtain that quality." But with
the general acceptance of the dynamical theory of heat, cold naturally
came to be regarded as a negative condition, depending o