arthquake, the whole
appears to have been rebuilt by Xenophon, the physician and poisoner of
the emperor Claudius. The final destruction was brought about by the
earthquake of A.D. 554. Among other things the precinct contains a
fountain of water with medicinal properties. It is doubtful whether this
water is brought from Burinna, the famous fountain of Hippocrates in the
mountain above.

_History._--Cos was a Dorian colony with a large contingent of settlers
from Epidaurus who took with them their Asclepius cult and made their
new home famous for its sanatoria. The other chief sources of the
island's wealth lay in its wines, and in later days, in its silk
manufacture. Its early history is obscure. During the Persian wars it
was ruled by tyrants, but as a rule it seems to have been under an
oligarchic government. In the 5th century it joined the Delian League,
and after the revolt of Rhodes served as the chief Athenian station in
the south-eastern Aegean (411-407). In 366 a democracy was instituted.
After helping, in the Social War (357-355), to weaken Athenian power it
fell for a few years to the Carian prince Maussollus. In the Hellenistic
age Cos attained the zenith of its prosperity. Its alliance was valued
by the kings of Egypt, who used it as an outpost for their navy to watch
the Aegean. As a seat ef learning it rose to be a kind of provincial
branch of the museum of Alexandria, and became a favourite resort for
the education of the princes of the Ptolemaic dynasty; among its most
famous sons were the physician Hippocrates, the painter Apelles, the
poets Philetas and, perhaps, Theocritus (q.v.). Following the lead of
its great neighbour, Rhodes, Cos generally displayed a friendly attitude
towards the Romans; in A.D. 53 it was made a free city. In A.D. 1315 it
was occupied by the Knights of St John; in 1523 it passed under Ottoman
sway. Except for occasional incursions by corsairs and some severe
earthquakes the island has rarely had its peace disturbed.

AUTHORITIES.--L. Ross, _Reisen nach Kos, &c._ (Halle, 1852), pp.
11-29, and _Reisen auf den griechischen Inseln_ (Stuttgart,
1840-1845), ii. 86 ff.; O. Rayet, _Memoire sur l'ile de Cos_ (Paris,
1876); M. Dubois, _De Co Insula_ (Paris and Nancy, 1884); W. Paton and
E. Hicks, _The Inscriptions of Cos_ (Oxford, 1891); B. V. Head,
_Historia Numorum_ (Oxford, 1887), pp. 535-537; _Archaol. Anzeiger_,
1905, i.; for coins see also NUMISMATICS: Greek, S "Ca