140 TEXTILE FABRICS. [V. 



See a full essay on this material in the Lond. Journ. xxxvi. 

 265-273. 



5. Dyeing. — Some goods will receive a color directly from 

 a solution and retain it, but in most cases it is necessary to 

 impregnate the goods first with a mordant or color-base, and 

 then to pass them through the dye, which adheres to the 

 color-base. We present a few suggestions which have been 

 recently made in reference to dyeing. 



In place of the cream of tartar used in woollen fabrics, a 

 patentee (Lond. Journ. xxxvi. 385) proposes mixtures of salts 

 and acids, enumerating 8 acids, 4 alkaline chlorides, 3 alkaline 

 sulphates, besides alkaline acetates, nitrates, oxalate, borate, 

 and sulphate of zinc. Out of these twenty salts and their 

 scores of compounds, one may possibly succeed. 



Recovery of Soap from Scouring — Where large quantities 

 of soap are used, as in scouring wool, cotton, &c., it may be 

 recovered by adding muriate of lime to the wash-water (which 

 is a solution of soap), and precipitating the salt of lime with 

 the fat acids. The salt, being collected, is easily decomposed 

 by sulphuric or muriatic acid, and the fat acids obtained to be 

 again used in the making of soap. This is the subject of an 

 English patent. See Rep. Pat. Inv. July, 1850. 



Orchil, Cudbear. — Lightfoot proposes (Lond. Journ. Sept. 

 1850) preparing vegetable textile fabrics by the Turkey-red 

 preparation (pearlash, olive-oil, and water) by 10-12 paddings, 

 then padding in acetate of alumina or aluminate of potassa, 

 and dyeing in orchil or cudbear. He also proposes impreg- 

 nating the goods with salts of magnesia, lead, zinc, copper, 

 tin, &c., and fixing the base by alkali before printing with 

 orchil or cudbear. The proposition to use cobalt or nickel 

 salts is absurd on account of their cost. 



Indigo. — According to Chevreul (Comptes Rendus, 1846) 

 indigo is more permanently fixed on woollen goods, dyed in 

 the hot vat, by steaming them, or by a boiling bath of alum 

 and argal, or tin-salt and argal, or by a bran-bath, or, lastly, 

 by a solution of potassa or soda. 



Red Prussiate of Potash. — Dr. Meitzendorfi" published an 



