The artists repository and drawing magazine: exhibiting the principles of the polite arts in their various branches (2.1788)

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ing them about the fhell; let it dry ; and when
dry, touch it with your finger, if any color
comes off, it requires a ftronger gum water ;
if.the color fhines and gliders when dry, the
gum water was too ftrong, and muft be qua-
lified by lowering it with fair water. Always
let it dry before you ufe it, then having wetted
it, cake a proper quantity in your pencil, tranf-
place it on the pallette, and mingle them as
the fubjecl requires.

But befides the colors which require the
treatment above defcribed, and which are
moftly earths, there are feveral ufeful colors
(extracted chiefly from vegetables) in the form
of tinctures ; to obtain which, the cuftomary
method is to boil the ingredients, with the ad-
dition of alum, in a quantity of water till the
water has acquired a fufficient ftrengrh of
color; fometimes the mixture is boiled yet
ftronger; and fometimes, but not often, the
fediment of the mixture after boiling is of ufe.

Colors are ranked as follows, white, yel-
low, orange, red, purple, blue, black.

White, and black, are the extremes of color.

......... *

yellow is the point of color next to white;
then green; then blue; green is compofed of
a mixture of yellow and blue ; orange of a
mixture of yellow and red; purple of a mix-
ture of red and blue; thefe compound colors

admit