Permanence of Colour
714.
The chemical colours afford evidence of very great duration. Colours fixed in glass by fusion, and by nature in gems, defy all time and re-action.
715.
The art of dyeing again fixes colour very powerfully. The hues of pigments which might otherwise be easily rendered mutable by re-agents, may be communicated to substances in the greatest permanency by means of mordants.
Notes
1 Wirkung, Beraubung; the last would be more literally rendered privation. The author has already frequently made use of the terms active and passive as equivalent to plus and minus.—T.
2 Wherever this word occurs incidentally it is translated pure red, the English word purple being generally employed to denote a colour similar to violet.—T.
3 No diagram or table of this kind was ever given by the author.—T.
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