If a similar paper be striped with sub-carbonate of potas and crossed with infusion of galls, and afterwards dipped in a solution of sulphate of iron, it will become purple, yellow, black and white.
Stain some parts of a sheet of paper a purple brown, with a mixture of infusion of galls and sulphate of iron; stain other parts green with a mixture of tinctures of turmeric and litmus; stain other parts purple with juice of red cabbage; other parts red, with tincture of litmus and muriatic acid; other parts yellow with tincture of turmeric; wash the remainder of the sheet with a solution of sulphate of iron, which will remain white. Then print or draw with a camel-hair pencil, any figure or figures on every part of the paper, with a solution of sub- carbonate of potas. On the purple brown, the figure will be black; on the green it will be purple; on the purple it will be green; on the red it will be blue; on the yellow, red; and on the white it will take a yellow colour. Thus the figure will appear in colours different from the ground in every part.
Immerse a piece of white cotton in a solution of sulphate of iron-it will remain white; dip another piece in tincture of turmeric, it will take a yellow; wet another piece with juice of red cabbage, containing also a few drops of muriatic acid,-it will be red; dye another piece green by immersing it in a mixture of tincture of turmeric and litmus; and another purple, by a mixture of infusion of galls and sulphate of iron. Let them dry; then immerse them altogether in a solution of sub-carbonate of potas. The white will be changed to a yellow; the yellow to a red; the red to green; the green to purple; and the purple to black; and it is not improbable that black might be materially changed or bleached by the same simple solution.