potash boiled in five parts of water. It is then dried, rubbed down, and
polished in the ordinary way.

The extract of walnut-shells and chromate of potash are procurable at
any large druggist's establishment. A dark-brown is the result of the
action of copper salts on the yellow prussiate of potash; the sulphate
of copper in soft woods gives a pretty reddish-brown colour, in streaks
and shades, and becomes very rich after polishing or varnishing.
Different solutions penetrate with different degrees of facility. In
applying, for instance, acetate of copper and prussiate of potash to
larch, the sap-wood is coloured most when the acetate is introduced
first; but when the prussiate is first introduced, the heart-wood is the
most deeply coloured. Pyrolignite of iron causes a dark-grey colour in
beech, from the action and tannin in the wood on the oxide of iron;
while in larch it merely darkens the natural colour. Most of the tints,
especially those caused by the prussiates of iron and copper, are
improved by the exposure to light, and the richest colours are produced
when the process is carried out rapidly.


=Imitation Ebony.=--Take half a gallon of strong vinegar, one pound of
extract of logwood, a quarter of a pound of copperas, two ounces of
China blue, and one ounce of nut-gall. Put these into an iron pot, and
boil them over a slow fire till they are well dissolved. When cool, the
mixture is ready for use. Add a gill of iron filings steeped in vinegar.
The above makes a perfect jet black, equal to the best black ebony. A
very good black is obtained by a solution of sulphate of copper and
nitric acid; when dry, the work should have a coat of strong logwood
stain.