To change the color of the hair various methods and preparations are
employed. The principal of these are intended to darken it, but
sometimes the contrary is aimed at. Whichever object is desired, it is
necessary that the article or preparation employed to carry it out be
not of a caustic or irritant nature, capable of injuriously affecting
the delicate skin to which it is applied, or that it may be liable to
come in contact with, as is the case with many of the nostrums vended
for the purpose. Some of the substances that necessarily enter into
the composition of hair strains and hair dyes, or that are used in
connection with them, possess these objectionable properties in a high
degree, and can, therefore, only be safely employed in a state of
proper dilution and combination. If any doubt exists respecting such
an article, it is a wise precaution to regard it with suspicion and to
test its qualities before applying it for the first time. This may be
done by placing some of it on the soft skin of the inner side of the
wrist or fore-arm, and allowing it to remain there as long, and under
the same conditions, as it is ordered to be left in contact with the
hair or skin of the head or face. In this way the injury or loss of
the hair, sores, and other serious consequences that too often follow
the use of advertised and ill-prepared hair dyes may be generally
avoided.

To gradually darken the shade of the hair on these principles,
provided its normal sulphur be still secreted by the hair-bulbs and be
still present in its structure, it will, therefore, generally be
sufficient to occasionally employ a weak solution of any of the milder
salts of iron as a hair wash. The menstruum may be water, to which a
little spirits and a few drops of oil of rosemary to increase its
stimulating qualities have been added. In applying it, the head being
first washed clean, care should be taken to thoroughly moisten the
whole surface of the hair and the skin of the head with the wash; and
its absorption and action should be promoted by the free use of a
clean hairbrush. Wine is the favorite solvent for the iron; ale and
beer are also sometimes so employed. Most of the fashionable
ferruginous hair washes also contain a few grains of acetate of copper
or distilled verdigris, the objections to which have been already
pointed out.

The daily use of oil or pomatum, with which a few grains of carbonate
of lead, lead plaster, or trisnitrate of b