Wash the stone with water and then coat chemical ink or strong soap-water over it and let it dry. Then clean the stone with oil of turpentine and ink-in well with acid-proof color. Dip a linen rag into gum water and phosphoric acid and endeavor to wipe away the color from the relief design. After wiping to and fro quickly a few times, try with the finger if the design will not whiten, or if the wiping with the acid must be continued. Care must be taken not to injure the ground through too much pressure. When the design gets pretty white, ink the stone with firm acid-proof ink, and then treat as in the preceding cases. In this way designs in relief that have not turned out as desired can be changed into intaglio, and then, by the use of successive coatings and etchings, as described before, improved by making gradations of tones. But it requires great skill, lacking which one may destroy his plates utterly. EXAMPLE IV _To change an intaglio design into relief for easier printing_ Many kinds of scripts and designs are easier to engrave with a needle than to do in relief with a pen; or one may have workmen who can use the engraving tool better than the pen, as the use of the latter requires more industry and skill than the use of the etching- or engraving-needle. If one wishes to transform such a design into one in relief, because then it can be printed more quickly and easily and also will give more impressions, the following method will prove useful:-- Ink the stone with good acid-proof ink, and after a few hours etch it like a pen design till it is apparent that the design is showing up. Let it rest again a few hours after etching and become quite dry. Then coat with gum. Otherwise treat it for printing like an ordinary pen design. * * * * * Now I believe that I have described faithfully and as clearly as I can all the lithographic methods to which unceasing research and endless experimentation have led me. In the following Appendix I merely make a few useful remarks, which do not pertain exclusively to lithography, yet are intimately connected with it and surely will not be unwelcome to art lovers. [Illustration] APPENDIX I PRINTING WITH WATER AND OIL COLORS SIMULTANEOUSLY When a plate, whether intaglio or relief, has been inked-in with oil color, it may be coated with one water color, or it may be illuminated with several, and then printed-off in one impression. Two parts of gum and one part of sugar are used for this. They can be dissolved with any water color. Care need be taken merely that the colors are well dried before the impression is made. If, however, it is desired that the colors have shades so that the impressions may resemble English or French colored copper-plate prints, the process is as follows:--