Is A Pigment Long Employed In India Under The Name Purree But Has Not
:
ON THE PRIMARY, YELLOW.
many years been introduced generally into painting in Europe. It is
imported in the form of balls of a fetid odour, and is produced from the
urine of the camel. It appears to be a urio-phosphate of lime, and is of
a beautiful pure yellow colour and light powdery texture; of greater
body and depth than gamboge, but inferior in these respects to
gallstone. Indian yellow resists the sun's rays with singular power in
water
painting; yet in ordinary light and air, or even in a book, the
beauty of its colour is not lasting. In oil it is exceedingly fugitive,
both alone and in tint. Owing probably to its alkaline nature, it has an
injurious effect upon cochineal lakes and carmine when used with them.
The colour is not damaged by foul air, and, as lime does not destroy it,
the pigment may be employed in fresco according to its powers.
Indian yellow washes and works extremely well, and is adapted for
draperies and for compounding landscape greens--where permanency is not
required. Blackness in the darkest shadows of the foliage will sometimes
result from too great a use of indigo; should this evil exist, no colour
is so fitted to regain the proper tone as Indian yellow employed
thickly.
TTITLE LAKES.
There are several pigments of this denomination, varying in colour and
appearance according to the substances used and modes of preparation.
Usually they are in the form of drops, and their colours are in general
bright yellow, very transparent, and not liable to change in an impure
atmosphere--qualities which would render them very valuable, were they
not soon discoloured and even destroyed on exposure to air and light,
both in water and oil. In the latter vehicle, they are bad driers, like
most lakes, and they do not stand the action of white lead and other
metallic pigments. If used, therefore, it should be as simple as
possible. Of these lakes, the following are the best; but it must be
borne in mind that, as not one of them is permanent, the compounds they
afford are of necessity unstable.
TTITLE YELLOW LAKE
Is a bright transparent yellow, a difficult drier, and liable to be
destroyed by light. It affords beautiful foliage tints, and would, if it
could be depended on, be of extreme value in what is called "glazing."
TTITLE ITALIAN PINK,