preservative agent in a greater or less degree. The vegetable colouring
matters do not penetrate so easily, probably on account of the affinity
of the woody fibre for the colouring matter, whereby the whole of the
latter is taken up by the parts of the wood with which it first comes
into contact. Different intermediate shades, in great variety, may be
obtained by combinations of colouring matters, according to the tint
desired, and the ideas of the stainer. The processes technically known
as "grounding and ingraining" are partly chemical and partly mechanical,
and are designed to teach the various modes of operation whereby the
above effects can be produced. We will commence with


=Imitation Mahogany.=--Half a pound of madder-root, and two ounces of
logwood chips boiled in a gallon of water. Brush over while hot; when
dry, go over it with a solution of pearlash, a drachm to a pint. Beech
or birch, brushed with aquafortis in sweeping regular strokes, and
immediately dried in front of a good fire, form very good imitations of
old wood. Venetian red mixed with raw linseed-oil also forms a good
stain.

The following is a method in common use by French cabinet-makers. The
white wood is first brushed over with a diluted solution of nitrous
acid; next, with a solution made of methylated spirits one gill,
carbonate of soda three-quarters of an ounce, and dragon's blood a
quarter of an ounce; and a little red tint is added to the varnish or
polish used afterwards. Black American walnut can be made to imitate
mahogany by brushing it over with a weak solution of nitric acid.


=Imitation Rosewood.=--Boil half a pound of logwood chips in three pints