The artists repository and drawing magazine: exhibiting the principles of the polite arts in their various branches (4.1790)

42 CHI

in reality without further thought) but fo as to give the
greateft life, force, and ftrength, to the total of the
picture, when furveyed as an aggregate, or collection of
parts.

This artifice, although the moil powerful attendant of
art, was long entirely unknown among artifts, thofe only
who ftudied colouring in its principles, made any con-
fiderable advances to the attainment of it ; and among
the Venetian fchool, we muff, look for its origin, which
at length was matured and regulated by the happy genius
of Rubens ; ever lince whofe time, this fyftem has been
efteemed the bafis of colouring.

The painter, working on a plane fuperficies, can im-
part the ideas of roundnefs and relief (not to fay of mo-
tion) to any object, only by an accurate and careful de-
gradation of tints; by the judicious oppofition and
heightenings of the lights, and their correfponding fha-
dows. Among fuch degradations may be reckoned, the
demi-tints, glazings, reflections, and accidents ; together
with fmart touches of lights, or of fhadows, as either
may be wanted ; or as either light or fhadow advances
before other parts; thereby caufing receffion, interval, or
diftance.

The chief principles of Chiaro Ofcuro are collec-
tion, and mutual support ; a kind of difcipine, not
unlike the arrangement of an army; wherein every
corps is collected and appointed to its place, and the
united ftrength of the whole augmented by principle
and method. This may be faid to diilinguifh an army
from a mob, though equally numerous ; fo mav judi-
cious appointment of light and fhadow, without any
greater quantity of either, or reinforcement, but merely
l by