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

fT^HE utility of the followingCoMPENDiuM^
will appear to all who confider the va-
riety of fubftances which compofe many
colors, and other materials ufed in the arts $
it is to be regretted that fome profeflbrs are
not more intimately acquainted with this part
of fcience, but this compilation is chiefly
intended for the fervice of ftudents, to whom
fuch information is evidently of great ad-
vantage.

It is univerfally agreed that an injudicious
mixture of pigments contrary in their natures,
produces very difagreeable confequences -a
which indeed are naturally to be expected*

from the various and diffimilar origin of
their ingredients. Some are products of the
animal, others of the vegetable kingdom;
fo(Tils afords fome ; minerals others; fome are
ufelefs without calcination,others will not bear
the fire; fome remain conftant in their colors,
and retain their proper hues; others though
briliant at firft, become after a while totally
corrupted, and by their corruption injure or
defrroy their companions, which might other-
wife have flood well.

A 2 It