504 AUXILIARY FOREST INDUSTRIES. 



colours that do not occur naturally. If the wood is to be 

 coloured superficially only, it is sufficient to paint it with the 

 stain. If it is to be stained throughout, as is necessary for 

 wood-mosaics, apparatus are used similar to those impreg- 

 nating wood with antiseptics. Staining does not obliterate 

 the texture of the wood. 



Brown stains are used for imitating oak and walnut wood, 

 or to give these woods the appearance of antiquity. Beech, 

 birch, hornbeam, spruce and silver-fir take brown colours well. 

 The staining matter is extract of the husks of walnut, Cassel 

 brown, catechu, manganese peroxide, potassium chromate, 

 gallic acid, extract of tar, etc. Black stains are used to 

 imitate ebony, the wood of the pear-tree, lime, hornbeam and 

 holly being suitable. Certain salts of anilin yield a black dye. 

 [A simple method is to brush the wood over with a strong 

 solution of sulphuric acid and water, also by boiling 1 Ib. of 

 logwood with J Ib. Brazil wood for 1J hours in a gallon of 

 water and brushing the wood several times with the hot 

 solution. Tr.J Red stains are used to imitate mahogany, 

 maple, ash, birch, alder and beech being suitable woods ; 

 alkanet (Alkanna tinctoria), cochineal and anilin dyes are used. 

 Green and yellow stains are made from verdigris and anilin. 

 Blue with indigo and anilin dyes. 



Painting wood increases its durability, excludes moisture, 

 prevents warping and conceals all its defects. Wood-paints are 

 produced by pounding lime and coloured substances such as 

 white lead, chalk, yellow ochre, verdigris, Prussian blue, red 

 lead, chrome red, lampblack, etc., with oil, lac, varnish (alcohol 

 or turpentine, with sandarac (gum of CaUitris quadriralris), 

 mastic or lac). Before applying the paint, the wood should 

 be prepared by filling its pores and unevennesses with putty. 



It may be noted that in Japan, pale birchwood is cut so 

 that yellow and red specks and stripes, due to fungi, appear, 

 and this improves the colour of the wood, which is then used 

 for turnery. 



3. Improvement in Lnxtrc. 



Polishing gives wood a permanent bright lustre, renders its 

 texture clear, excludes humidity and prevents warping and 



