: ON THE SECONDARY, PURPLE.
A purple powder is capable of being produced from bismuth by passing
chlorine gas through the hydrated oxide suspended in a saturated
solution of potash. As soon as the oxide becomes brown-red, the mixture
is boiled and the liquid decanted off at once, the residue being
immediately washed first with alcohol and then with water. On the whole,
the result is not, for an artistic pigment, worth the trouble involved
in the preparation.