essel is often of a different
tint from the exterior. Many of these vases are decorated with figures
or designs in relief, others are quite plain. The colours of these
glazes are of course due to the addition of oxide of copper and oxide
of iron to a lead glaze, and they are strictly analogous to the green
and yellow glazes of medieval Europe.[7]

HISTORICAL ACCOUNT OF GREEK VASE-PAINTING.--It has been indicated in the
section dealing with technical processes that Greek vases may be
classified under four headings according to the character of the
decoration, and this classification may with a slight modification be
adopted as a chronological one, the history of the art falling under
four main heads, under which it will be convenient to describe its
development from the earliest specimens of painted pottery down to the
period when it was finally replaced by other methods of decoration.

These four classes and their main characteristics may be summarized as
follows:--

I. _Vases of the Primitive Period_ from about 2500 or 2000 to 600
B.C., including both the Cretan-Mycenaean epoch and the early ages of
historical Greece. In the former the pottery is either decorated in
polychrome on a shining black ground or conversely in shining black on
a buff ground; in the latter, the decoration is in brown or black
(usually dull, not shiny) on an unglazed ground varying from white to
pale red. In the former again the decoration is marked by its
naturalistic treatment of plant and animal forms; in the latter the
ornaments are chiefly linear, floral or figures of animals; human
figures and mythological scenes being very rare.

II. _Black-figured Vases_ from about 600-500 B.C.; figures painted in
shining black on a glossy ground varying from cream colour to bright
orange red, with engraved lines and white and purple for details;
subjects mainly from mythology and legend.

III. _Red-figured Vases_, from 520 to 400 B.C.; figures drawn in
outline on red clay and the background wholly filled in with shining
black, inner details indicated by painted lines or dashes of purple
and white, scenes from daily life or mythology. With these are
included the vases with polychrome figures on white ground. In these,
which are exclusively made at Athens, the perfection of vase-painting
is reached between 480 and 450 B.C.

IV. _Vases of the Decadence_, from 400 to 200 B.C.; mostly from
so