The following method of polishing wood with charcoal is now much used by French cabinetmakers, and produces that well-known beautiful dead black color, with sharp clear edges and a smooth surface, which give the wood the appearance of ebony. When articles of furniture finished in this way are viewed side by side with furniture rendered black by paint and varnish, the difference is so sensible that the considerable margin of price between the two kinds explains itself without need of any commentary. The operations are much longer and much more minute in charcoal polishing, which respects every detail of the carving, while paint and varnish would clog up the holes and widen the ridges. Only carefully selected woods, of a close and compact grain, are employed. These are covered with a coat of extract of logwood and nutgalls dissolved in water; and almoso immediately afterward with another coat composed chiefly of sulphate of iron, or green vitriol, dissolved in water. The two compositions in blending penetrate the wood and give it an indelible tinge, and at the same time render it impervious to the attacks of insects.
When these two coats are sufficiently dry the surface of the wood is first rubbed with a very hard brush of scouring grass, and then with charcoal of substances as light and friable as possible, because if a single hard grain remained id the charcoal this alone would scratch the surface, which should be rendered perfectly smooth. The flat parts are rubbed with natural stick charcoal, the indented portions and crevices with charcoal powder. At once, almost simultaneously, and alternately with the charcoal, the workman also rubs the piece of furniture with flannel soaked in linseed-oil and the essence of turpentine. These pouncings, repeated several times, cause the charcoal powder and the oil to penetrate into the wood, giving the article of furniture a beautiful color and perfect polish, which has none of the flaws of ordinary varnish. Black wood, polished with charcoal, is coming day by day to be in greater demand. It is most serviceable; it does not tarnish like gilding, nor grow yellow like white wood; and in furnishing a drawing-room it agrees very happily with gilt bronzes and rich stuffs. In the dining-room, too, it is thoroughly in its place to show off the plate to the greatest advantage; and in the library it supplies a capital framework for handsomely bound books.