ly;
also, box cooked in olive oil is good for it, or well-planed pear soaked
with _aqua fortis_, and then coloured with ink several times; or stew
the wood in lamp-black, and soak with oil.

Blue may be obtained by the use of a solution of copper brushed hot over
the wood several times; then brush hot a solution of pearl ash, 2 oz. to
a pint of water, until the wood becomes perfectly blue. The copper
solution is prepared in this way:--"Take of the refiner's solution of
copper made in the precipitation of silver from the spirit of nitre; or
dissolve copper in spirit of nitre, or _aqua fortis_, by throwing in
filings or putting in strips of copper gradually till all effervescence
ceases. Add to it starch finely powdered, one-fifth or one-sixth of the
weight of copper dissolved. Make a solution of pearl ash and filter it;
put gradually to the solution of copper as much as will precipitate the
whole of the copper. The fluid becomes colourless. Wash the powder, and
when so well drained of water by means of a filter as to be of the
proper consistence, grind well together, and lay out to dry. This makes
dark verditer." Indigo may also be used, prepared with soap lees as when
used by dyers; brush it over the wood boiling hot. With a solution of
cream of tartar, 3 oz. to a quart of water, and boiled, brush over the
wood copiously before the moisture is quite dried out. A German receipt
says:--Put 4 oz. of Tournesol in three parts of lime water to cook for
an hour and spread it on the wood. "Wood coloured green with verdigris
can be made blue by using pearl ash." This is the process described
first.

For green verdigris dissolved in vinegar may be used; or crystals of
verdigris in water, brushed hot over the wood. A 15th century MS. gives
a traditional mode thus:--"Wood, bone, small leaves, and knife handles
can be made green by strong, red vinegar and brass filings mixed
together with a little Roman vitriol and stone alum in a glass vessel.
When it has stood for a day the object is dipped in it, and steeps
itself in the liquid. The colour will be very permanent." A German
receipt says:--"Take walnut shells from the green fruit, and put in very
strong lye with some copper vitriol and alum to stew for two or three
hours. The wood must be put in strong wine vinegar for several days,
then it is put in the above-mentioned mixture, to which ground verdigris
mixed with vinegar is added. Or you can mix this ground verdigris with
vineg