Dyeing Catchecu Colors on Cotton.

Scientific American 24, 3.3.1849

To 10 pounds of cotton goods, boil up 2½ pounds shumac, and steep the yarn or cloth (every dyer knows the manner,) in the liquor for 8 or 10 hours, then squeeze or wring them out and run them through a tub of the black oxide of iron at 3°, after which, wring them out and clear with soda ley, then wash, wring up, and put the goods through hot liquor of catchecu, at the rate of 2 pounds to the 10 and 2 pounds of logwood, some more, and some not quite as much; there is a great difference in the quality of this eastern drug. Afterwards, run the goods through a solution of soda ley to blue fown, as the dyer calls it; this is to take away the brown shade of the catchecu.

Catchecu is most extensively used in dyeing browns and drabs. It is an astringent substance, used in chewing with the beteel but, by the Hindoos.


Browns.

To 10 lbs. goods, give 2 lbs. of catchecu as warm as it possibly can be handled, allowing q½ catchecu at each run, or giving the goods two dips and I gill of the nitrate of copper in tubs, at each dip by itself, then run through a solution of the chromate of potash.

Drabs are done in the same manner as the browns; but sometimes, (as the shade is wanted,) get some sulphate of iron in tubs separate, before getting the crome, and they are cleared up, first, by running the goods through a tub in milk warm water in which there is about a gill of muriate acid, then washed and run throygh a tub of soda ley, and then washed and finished.


Madder Black.

The old fast black was done by first immersing in shumac 2½ lbs. to the ten of goods, washing them out and then givig them a dip in the blue vat, afterwards a mordant of the oxide of iron, cleared with soda ley, washed and dyed in a madder bath at the rate of 70 to 80 pounds to the 50 of goods.