=Imitation Purple-wood Stain.=—­Grind a piece of green copperas on coarse glass-paper, and mix with polish coloured with red-sanders.  This makes a capital purple stain, and is used by French cabinet-makers.

These dyestuffs may be much improved by the addition of a mordant applied after they are dry; this will greatly assist in modifying and fixing the tints and shades which the dyes impart.  The best thing for the purpose, in the writer’s opinion, is clear ox-gall, which, besides being useful as a mordant, will destroy all unctuous matter.

=Chemicals used in Staining.=—­It may perhaps be useful here to give the common or popular names of the chemicals employed in the operations of staining and imitating, as few polishers know them by the scientific names used by chemists:—­

Nitric acid is but another phrase for aquafortis. 
Sulphuric acid, for oil of vitriol. 
Ammonia, for spirits of hartshorn. 
Sulphate of magnesia, for Epsom salts. 
Nitrate of potass, for sal prunelle. 
Chlorine, for aqua regia. 
Sulphate of copper, for blue vitriol. 
Subborate of soda, for borax. 
Superoxalate of potass, for salts of sorrel. 
Hydrochlorate of ammonia, for sal ammoniac. 
Subnitrate of bismuth, for flake white. 
Acetic acid, for vinegar. 
Acetate of lead, for sugar of lead. 
Sulphate of lime, for gypsum. 
Carbonate of potass, for pearlash. 
Bitartrate of potass, for cream of tartar. 
Nitrate of silver, for lunar caustic. 
Supercarbonate of iron, for plumbago. 
Cyanide of iron, for Prussian blue. 
Subacetate of copper, for common verdigris. 
Susquecarbonate of ammonia, for sal volatile. 
Alcohol, for pure spirit. 
Sulphate of iron, for green copperas. 
Sulphate of zinc, for white copperas.

=Process of Staining.=—­The natural qualities of woods are very variable; so also are the textures of the different sorts usually used for staining.  It will be readily perceived that there is no fixed principle upon which certain peculiar tints or shades can be produced with any degree of certainty.  In order to arrive at the best results, the stainer is recommended to observe the following rules:—­

All dry stuffs are best reduced to powder, when it is possible, before macerating or dissolving them.

All liquids should be strained or filtered before use.

The requisite ingredients should always be tested before a free use is made of them, as the effect produced by a coat of stain cannot be accurately ascertained until it is thoroughly dry.