Scheele’s green for the calico-printer is made as follows:—
Take 1 gallon of water, in which dissolve with heat,
5 pounds of sulphate of copper, and 1 pound of verdigris. When the two salts are dissolved, remove the kettle from the fire, and put into it 1 quart of solution of nitrate of copper, and 5 pounds of acetate of lead. Stir the mixture to facilitate the decomposition, and allow the pigment to subside.
It must be thickened with 21⁄2 libs. of gum per gallon, for pencilling; or 12 oz. of starch for the block. The goods printed with this paste are to be winced through a caustic lye, till a fine sky-blue be produced; then washed well and rinsed. They are now to be passed through water, containing from half an ounce to an ounce of white arsenic per piece; 4 turns are sufficient; if it be too long immersed, it will take a yellow tint.
Catechu has been considerably employed by calico-printers of late years, as it affords a fine permanent substantive brown, of the shade called carmelite by the French. The following formula will exemplify its mode of application:—
Take 1 gallon of water;
1 pound of catechu in fine powder; reduce by boiling to half a gallon, pass the decoction through a fine sieve, and dissolve in it 4 ounces of verdigris; allow it then to cool, and thicken the solution with 5 ounces of starch; while the paste is hot, dissolve in it 5 ounces of pulverized muriate of ammonia.
Print-on this paste, dry, and wash. It is a fast colour.
I shall subjoin the prescriptions for two fancy cochineal printing colours.
Amaranth by cochineal.—Pad the pieces in the aluminous mordant of spec. grav. 1·027, [page 224].
Dry in the hot flue; and after hanging up the goods during 3 days, wince well through chalky water, and then dye, as follows:—
For each piece of 28 or 30 yards, 8 ounces of cochineal are to be made into a decoction of 2 gallons in bulk, which is to be poured into a kettle with a decoction of 3 ounces of galls, and with 2 ounces of bran. The pieces are to be entered, and winced as in the madder bath, during two hours and a half; then washed in the dash wheel. On mixing with the amaranth bath a certain quantity of logwood, very beautiful lilacs and violets may be obtained.