Page:Cyclopedia of Painting-Armstrong, George D (1908).djvu/424

416 the golden color is dark enough. The sieve and articles are now taken out, and the latter are washed and then dried in sawdust. If the brass is left longer in the copper solution, in a short time a fine green lustre is produced, becoming yellow at first and then bluish green. After, it turns green, then the well-known iridescent colors finally appear. To obtain uniform colors it is necessary that they be produced slowly, at temperatures between 135° and 170° Fahrenheit. The copper bath can be used repeatedly, and can be kept a long time, if bottled up tightly, without change. After it is exhausted it can be renewed by adding $3/8$ of an ounce of caustic soda, replacing the water that has evaporated, heating to boiling, and adding $7/8$ of an ounce of a cold solution of blue vitriol.

Harmonious Colors. A whole wall, ceiling, or other space should not be entirely covered over with rich ornament, and so also in a colored piece of drapery or other ornamental work, it is better to have some portion of it much less rich and of less complicated pattern than the rest, and in some cases to have only a border round a single ground destitute of any pattern, as it is apt to fatigue the eye when overloaded with an equal richness of detail throughout. This is still more important in a colored building, where, if the whole walls, columns, and other parts are covered with elaborate and colored patterns, the eye feels a want of repose, and the same when a building is covered entirely with sculptured ornament without color. The richly carved part not only requires an unsculptured portion in order that it shall not fatigue the eye, but is improved and set off by the contrast, and contrast is as necessary for effect in form, quantity of detail, position of lines, as it is in color. On this principle great effect is sometimes given to a colored pattern by having a portion of the composition on the wall of the building without any color at all, and for the same reason an expanse of wall in a room often looks well when painted with a single