2644. Liquid Yellow

2644.    Liquid Yellow. Dissolve gamboge in water, and add a little gum-arabic and alum. Used for ink, to stain paper, color maps, etc.. Or, dissolve gamboge in equal parts of proof spirit and water. Golden colored. Or, steep French berries in hot water, strain, and add a little gum and alum. Or, steep turmeric, round zedoary, gamboge, or annotto, in spirits of wine. Or, dissolve annotto in a weak lye of subcarbonate of soda or potash. The above are used by artificial florists.

2645. Liquid Bed

2645.    Liquid Bed. Macerate ground Brazil in vinegar, boil a few minutes, strain, and add a little alum and gum. Or, add vinegar to an infusion of litmus till it turns red. Or, boil or infuse powdered cochineal in water; strain, and add a little alum and gum. Or, dissolve carmine in liquor of ammonia, or in weak carbonate of potash water; the former is superb. (See No. 2623 (Cochineal Coloring), etc..)

2646. To Tint Maps or Architects' Plans

2646.    To Tint Maps or Architects' Plans. Maps, paper, or architects' plans may be tinted with any of the simple liquid colors just mentioned. To prevent the colors sinking and spreading, which they will usually do on common paper, the latter should be wetted 2 or 3 times with a sponge dipped in alum water (3 or 4 ounces to the pint), or a solution of white size; observing to dry it carefully after each coat. This will tend to give lustre and beauty to the colors. The colors themselves should also be thickened with gum. Before varnishing maps after coloring them, 2 or 3 coats of clean size should be applied with a brush.

2647. Sizing for Prints or Engravings to be Colored

2647.   Sizing for Prints or Engravings to be Colored. Dissolve 4 ounces finest pale glue, and 4 ounces white curd soap, in 3 pints boiling water; add 2 ounces powdered alum. Used for sizing prints and engravings before coloring them.

2648. Druggists' Show Colors

2648.    Druggists' Show Colors. These are bright and perfectly transparent liquid colors, employed by druggists in ornamental bottles for purposes of display, forming an attractive and distinctive ornament of a drug store window. It has for a long time been tried to render the beautiful colors of permanganates more permanent. They are liable to decompose under the influence of light and atmospheric dust, and no way has as yet been discovered to obviate this difficulty. Many druggists have proposed to fill the bottles in their windows with solutions of aniline colors, but even these have to be renewed from time to time. Neutral metallic salts, that have neither tendency to oxydize nor to reduce, are best employed for this purpose. The receipts here given are among the very best and most used for this purpose. The mixtures require careful filtration through powdered glass in a glass funnel. It will be found desirable to make a little more liquid color than is actually required, to replace the loss occasioned by a second filtration (performed in the same manner as the first), which will probably be necessary after exposure for a few weeks to the light: as any addition of water after filtration, to make up the deficiency, tends to weaken the color and detract from its brightness. Druggists' show-bottles are now made of colored glass, and filled with pure water. These are just as effective as the white glass bottles filled with colored waters, and obviously involve much less trouble.