Prussiate Of Copper

differs chemically from Prussian blue only in having copper instead of

iron for its basis. It varies in hue from russet to purple brown, is

transparent and deep, but, being very liable to change in colour by the

action of light and by other pigments, has never been much used, and is

now obsolete. The compound has the objection of containing free

prussiate of potash, not removable by continued washing--sometimes as

much as five per cent.

* * * * *

There are several other pigments which enter imperfectly into, or verge

upon, the class of russet, which, having obtained the names of other

classes to which they are allied, will be found under other heads; such

are some of the ochres, as Indian red. Burnt carmine is often of the

russet hue, or convertible to it by due additions of yellow or orange;

as are burnt Sienna and various browns, by like additions of lake or

other reds.

The one pigment in this chapter known to the modern palette, Rubens'

madder, is permanent.


Olive is the third and last of the tertiary colours, and nearest in

relation to shade. Like its co-tertiaries, citrine and russet, it is

composed of the three primaries, blue, red, and yellow; but is formed

Prussian Purple Purple Black facebooktwittergoogle_plusredditpinterestlinkedinmail