ess varieties of sculpture, metal work, and textile fabric, depend
for great part of the effect, for the mystery, softness, and clearness
of their colours, or shades, on modification of the surfaces by lines or
threads. Even in advanced oil painting, the work often depends for some
part of its effect on the texture of the canvas.

136. Again, the arts of etching and mezzotint engraving depend
principally for their effect on the velvety, or bloomy texture of their
darkness, and the best of all painting is the fresco work of great
colourists, in which the colours are what is usually called dead; but
they are anything but dead, they glow with the luminous bloom of life.
The frescoes of Correggio, when not repainted, are supreme in this
quality.

137. While, however, in all periods of art these different textures are
thus used in various styles, and for various purposes, you will find
that there is a broad historical division of schools, which will
materially assist you in understanding them. The earliest art in most
countries is linear, consisting of interwoven, or richly spiral and
otherwise involved arrangements of sculptured or painted lines, on
stone, wood, metal or clay. It is generally characteristic of savage
life, and of feverish energy of imagination. I shall examine these
schools with you hereafter, under the general head of the "Schools of
Line."[12]

[Footnote 12: See "Ariadne Florentina," Sec. 5.]

Secondly, even in the earliest periods, among powerful nations, this
linear decoration is more or less filled with chequered or barred shade,
and begins at once to represent animal or floral form, by filling its
outlines with flat shadow, or with flat colour. And here we instantly
find two great divisions of temper and thought. The Greeks look upon all
colour first as light; they are, as compared with other races,
insensitive to hue, exquisitely sensitive to phenomena of light. And
their linear school passes into one of flat masses of light and
darkness, represented in the main by four tints,--white, black, and two
reds, one brick colour, more or less vivid, the other dark purple; these
two standing mentally their favourite +porphyreos+ colour, in its
light and dark powers. On the other hand, many of the Northern nations
are at first entirely insensible to light and shade, but exquisitely
sensitive to colour, and their linear decoration is filled with flat
tints, infinitely varied, but with no expression of