It must be remarked that this process, like all the applications of the " hydrosnlphite " to dyeing and printing, is patented in the United Kingdom.
In the "lapis style," mordants with reserves are printed on. The following are specimens of these compositions.
White Lapis resist (for block and machine).—Water, 51 pints; lime-juice at 531. Tw., 6 lb. 9 oz. ; pipe-clay, 11 lb. Mix also separately : water, 51 pints ; lime-juice at 531° Tw., 4 lb. 6 oz. ; corro sive sublimate, 3 lb. 13 oz.; calcined starch, 11 lb. ; lard, 12} oz. ; turpentine, 61 oz.; muriate of zinc at 98° Tw., n lb. Mix and boil.
Red Lapis liquor, 7 pints; verdigris, oz.; pipe-clay, 9 lb. 13 oz. ; lard, 41 oz. ; turpentine, 44 oz. Diesolvo also separately : arsenious acid, 121 oz.; acetate of alumina, 51 pints. Mix also apart : acetate of alumina, pints ; gum senegal, 3} lb. ; muriate of zinc at 98° Tw., 17} oz. ; extract of logwood at 61° Tw., 81 fl. oz. Mix these three parts with the aid of heat, grinding them very well, and straining before use.
The cylinders for printing should be engraved very deeply. The pieces are next aged for 48 hours, at a temperature of 85° (95° F.), with the wet-bulb thermometer at 32° (89° F.). Dry for 12 hours thoroughly at 30° (86° F.). If left damp, the pieces will not resist the vat.
Dye blue for 3-5 minutes in the cold vat. Drain, wash for hour in a current of water. Dung in folds for 1 hour in a beck at 60° (140° F.), with 4 pails of thing, and 15} lb. chalk, for 6 pieces of about 50 yds. Wash; and dung a second time, in the same matter, but without chalk ; and wash.
Dye for 2 hours at 60°-70° (140°-158° F.), in the following beck :—Garanoine (for which will now be substituted a proportionate quantity of alizarin), 8/ lb. ; sapan-wood, 6 lb. 9 oz. ; sumach, 11 lb. ; bark, 174 lb. ; glue in jelly, 7 pints (containing 17} oz. dry glue).
Wash till no more colour rune off; oblore at f° Tw. Wash ; dry ; block in yellow, if needed ; and age for 24 hours at 30° (86° F.), the wet-bulb thermometer standing at 27° (80° F.).
Here may be introduced a notice of the patented process of the late John Lightfoot, for com bining indigo and madder effects (No. 3668, Deo. 26th, 1867).
He takes dry indigo, ground and prepared, 11 lb. ; tin crystals, lf lb. ; caustic soda at 30° Tw., 1 gal. These materials are put into the colour pan, and raised to a boil in f hour, when 1 gal. boiling water is added. The mixture is then allowed to become quite cold, and 2 gal. cold water are added, in which I lb. sugar has been previously dissolved. To this solution, are added 2f pinta muriatic aoid at 32° Tw., or 1 pint ordinary oil of vitriol, previously diluted with 1 pint water, and allowed
to stand till cold, or 3 qte. aoetio acid at 80° Tw. The indigo blue may also be precipitated by a mixture of double muriate of tin at 120° Tw., with any of the acids above mentioned, taking f pint of the tin solution to half the quantities of acid given above. But of all these precipitants, acetic) acid alone ie preferable. The indigotine precipitate is filtered through a deep conical filter, leaving exposed to the air as small a surface as possible. The pulp obtained from the above quantities, when filtered, should measure about 1 gal.
To make a blue colour for printing, the patentee takes 4 gal. of the above precipitated indigo, and 14 lb. gum senegal in powder, stirring till dissolved. The colour, when strained, is ready for printing.
For a green colour, he takes 4* gal. indigotine precipitate, 18 lb. powdered gum eenegal, stirring till dissolved ; 11 lb. nitrate of lead, and 11 lb. white sugar of lead, both in powder. The mixture is stirred till all is dissolved, and ie then strained.
Compound colours are made by mixing the blue and green colours with each other, or with ordinary mordants for dyeing. With the blue and green above described, and with the ordinary iron and alum mordants (as used in madder-work), he prints calico, and, after cooling, ages the pieces for a night. They are then fixed by passing the pieces into a solution of silicate of soda at 8° Tw., to which is added 1 oz. powdered chalk in a gal. This bath is in a cistern fitted with rollers at top and bottom, and heated to 32° (90° F.). The pieces pass through this solution at the speed of 25 yds. a minute. They are then rinsed in a tank of cold water, fitted with a reel about 4 ft. above tho surface. By this process, the indigotine attached to the fibre is rendered blue. If the green mixture has been printed on, the pieces are next passed into a chrome beck at 38° (100° F.), con taining 1 oz. biohromato of potash in a gal. of water. Here the pieces remain for 5 minutes, and are then washed. They are next submitted to second dunging (the passage through silicate of soda being the fly-dunging) for 15 minutes, at 38° (100° F.), in a beck of cow-dung and water. They are next washed in water, and dyed with madder, munjeet, flower of madder (alizarine), garancine, cochineal, or mixtures of garancine with sumach and bark. The grounds are then cleared in the ordinary manner, preferably with chloride of lime.