I. A pink cosmetic for the cheeks. Varieties are prepared from carmine and from the dried leaves of the safflower or carthamus. The latter furnish the delicate sort known as vegetable rouge. The leaves, thoroughly washed, are dried, and then pulverized and digested in a weak solution of carbonate of soda. Into this is placed some finely carded cotton, and the alkaline mixture is neutralized with lemon juice or vinegar. The red coloring matter collects on the cotton, and this being washed with water to remove the yellow matter, the rouge is again dissolved, and some finely pulverized talc is introduced into the solution before it is again precipitated with the acid. Upon this the red color is received, and when separated from the liquid the two are thoroughly mixed by trituration, a little olive oil being rubbed in to add to the smoothness. Sometimes woollen threads are placed in the second solution to receive the rouge when it is precipitated, and these, called crepons, are used to rub the color upon the cheeks.
For further accounts of this coloring material, see Carmine, Cochineal, and Safflower.
In The Arts, a pigment known as English red, also used as a polishing powder, made with peroxide of iron. As the perfection of the specula of telescopes depends upon the fineness and efficiency of the rouge used for polishing them, the preparation of this article has received much attention from scientific men, and various processes are employed to insure its greatest purity. Lord Rosse gives the following as his method. The peroxide of iron is precipitated by ammonia from a pure dilute solution of sulphate of iron, and the precipitate after being washed is compressed under a screw press until nearly dry, and then exposed to a heat which in the dark appears only of a dull low red. The color thus obtained should be a bright crimson inclining to yellow. If potash or soda is used instead of ammonia to precipitate the oxide of iron, a trace of the alkali always remains, injuring the polishing property of the rouge.