17 Pearl White
:
ON COLOURS AND PIGMENTS INDIVIDUALLY.
Is an insoluble basic nitrate of bismuth, a pearly white powder of loose
texture, turning grey on exposure, and blackened by sulphuretted
hydrogen. It is chiefly used as a cosmetic, but is said to injure the
skin, rendering it yellow and leather-like; and it has been known to
cause a spasmodic trembling of the face, ending in paralysis.
Another preparation under this name, and now obsolete we believe as a
pigment, was obtained from mother-of-pearl. It is described as
exquisitely white, and of good body in water, but of little force in oil
or varnish.