When the cotton has been three times dipped in this soapy water, and three times dyed, the same process is repeated, except that the sheep's dung is left out; the liquor is also preserved for brightening. The cotton, having gone through these processes, should be as white as if it had been bleached.
When dry it is to be galled, using a quarter of a pound of galls to every pound of cotton; after this it is dried, then take six ounces of alum for the first aluming; it is then to be dried again, and to hang three or four days in the air, and then, when dry, to be alumed again; four ounces of alum, and four of the lixivium may be added to the last alum water.
The madder used for this red is called lizary, which furnishes a dye incomparably finer than that produced by any other madder. Of lizary madder, therefore, take two pounds for every pound of cotton, and twenty pounds of liquid sheep's blood well mixed with the water in the copper before the madder is put in. The butcher should stir the blood to prevent its coagulating; the copper should be carefully skimmed; the madder should not boil, but be brought during the process from blood-heat to within a few degrees of the boiling point: if it boil at last, as some prefer it, it should only be for a few minutes.
In order to brighten the colour, the cotton is dipped in a lixivium of fresh wood ashes, and five pounds of white soap: yellow or mottled soap is improper. When the cotton has been well worked in this liquor, it is, with the liquor itself, put into a copper sufficiently large to hold it with some addition of water, and made to boil over a slow fire, for three, four, or more hours. The liquor must be covered with coarse white linen cloths, to keep as much steam in as possible.
Some of the skeins of cotton must be taken out from time to time, and washed perfectly; when the red is judged perfect and sufficiently bright, the fire is withdrawn.
If instead of the wood-ash lixivium and soap, the two reserved liquors and soap are used, the red will be much brighter than the finest Adrianople carnation.
Miscellaneous observations relative to Adrianople red.
In regard to the above processes, we may observe, that those given for Adrianople red in Ure's Berthollet, are more numerous, being regularly numbered to the seventeenth, or last operation called brightening. After a careful attention to those processes we see no reason to alter our own, yet we nevertheless advise the dyer to become acquainted with what is stated in that work, many details being there given for which we have not room, particularly for making different shades of the colour. We add, however the following from vol. ii. p. 140.
"Cotton dyed red, may, moreover, be made to pass through all the shades, down to the palest orange, thus: pure nitric acid is diluted with two-fifths of water; chips of tin are oxidized in it till the liquor grows opal; the solution is employed at different strengths; the colour varies according to the concentration of the solution: when it is strong, shades are obtained which have some relation to those of scarlet.
"In general, when brilliant colours are desired, we must not charge them too much with oil; we must give feeble leys long repeated, charge little with alum, employ the best madders, and, at last, brighten powerfully without sparing soap."