DYEING AND CALICO PRINTING.
694
pieces, and raise the heat to 120° F.; add 4 lbs. of soap, dissolved in a littlewater. Dye in the same time and at the same heat as for mauve, and washwell. No clearing is generally required, but if the whites are not satisfactorythey must be winced in soap, and on no account passed through bleaching-liquor. A wooden dye-beck must be used.
Second Method, for Single Colour Black and Mauve, or Dark Work.
No. 1. Standard for Pale Shades .—
Gum Senegal water .. J gal.
Water . J „
Tannic acid.8 ozs.
Mauve to shade up to.12 ,,
No. 2. Standard Medium .—
Gum-water and water as above.
Tannic acid.16 ozs.
Mauve to shade up to.20 „
No. 3. Standard, Dark.
Gum tragacanth water (1 lb. per gal.) . | gal.
Water . i „
Tannic acid.24 ozs.
Mauve to shade up to.30 or 35 „
A small quantity of glycerin added to the printing colours is an improvement.Print on madder-bleached cloth, without any further preparation ; age onenight and steam forty-five minutes at 1 lb. pressure to the inch, run throughthe fixing-beck, wash, and finish. Magenta by this process is not so good asby the former method.
Artificial Orchil.
The following process has been patented in France (No. 97,641, Dec., 1872)by Messrs. Vogt and Henninger:—Toluene, or its monochloride or mono-bromide, is treated with concentrated sulphuric acid. To the acid mixtureare added lime and carbonate of lime, so as to separate the excess of sulphuricacid as insoluble sulphate of lime. Or, in order to economise sulphuric acid,the acid mixture above mentioned may be allowed to a£t upon common salt,when hydrochloric acid is given off, and the residue contains sulphate of sodaand the compound disulpho- or chloro-or bromosulpho-conjugated acids oftoluene. A certain quantity of water is added, and the liquid containing thecompound acids is decanted, and neutralised with lime. The solution thencontains the disulphotoluate or chloro- or bromo-cresylo-sulphite of lime,which are then transformed into soda-salts by adding sulphate or carbonate ofsoda. The compound salts, when dry, are melted with double their weight ofsoda and (or ?) potash, either under pressure or in open vessels, and furnishorcin, and the salicylates and cresylates of soda and (or ?) potash. The re-action is effected at the temperature of 280° or 300° C.
The melted mass is then dissolved in water, saturated with hydrochloric orsulphuric acid, concentrated, and the alkaline chlorides or sulphates areremoved by crystallisation. The mother-liquor contains orcin, which istransformed into orcein by the joint action of ammonia, lime, and atmosphericoxygen. (See p. 375).