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,



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