It contains a principle termed
"Carthamin" or "carthamic acid," which can be separated by exhausting
safflower with cold acidulated water (sulphuric acid) to dissolve out a
yellow colouring matter which is useless. The residue after washing free
from acid is treated with a dilute solution of soda crystals, and the
liquid is then precipitated by an acid. A red precipitate is obtained,
which fixes itself directly on cotton thread immersed in the liquid, and
dyes it a delicate rose pink, which is, unfortunately, very fugitive.
Silk can be dyed like cotton. The colour is not fast against light.
Turmeric is the root portion of a plant called _curcuma tinctoria_, that
grows in Southern Asia. The principle forming the colouring matter is
"Curcumin." It is insoluble in cold water, not much soluble in hot, but
easily soluble in alcohol. From the latter solution it separates in
brilliant yellow crystals. Although the colour it yields is very
fugitive, the wool and silk dyers still use it for producing especially
olives, browns, and similar compound shades.
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