cotton without the aid of a mordant, consists of the petals of the
flower of _carthamus tinctorius_. 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. It produces on cotton and
wool a bright yellow colour without the aid of any mordant. To show you
how easily dyeing with turmeric is effected, I will warm some powdered
turmeric root in a flask with alcohol, and add the extract to a vessel
of water warmed to about 140° F. (60° C.), and then dip a piece of
cotton in and stir it about, when it will soon be permanently dyed a
fine bright yellow. A piece of wool similarly worked in the bath is also
dyed. However, the unfortunate circumstance is that this colour is fast
neither to light nor alkalis. Contact with soap and water, even, turns
the yellow-dyed cotton, reddish-brown.

Annatto is a colouring principle obtained from the pulpy matter
enclosing the seeds of the fruit of a tree, the _Bixa orellana_, growing