5). Saxon Blue.—
Put into a glazed earthen pot 4 lbs. of good oil of vitriol with 12 oz. of choice Indigo, stir this mixture very hastily and frequently in order to excite a fermentation. It is customary with some Dyers to put into this composition a little antimony or salt-petre, tartar, chalk, alum and other things, but I find it sufficient to mix the oil and Indigo alone, and the colours will be finer, for those neutral salts destroy the acid of the vitriol and sully the colour. In 24 hours it is fit for use. Then a copper of a good size is to be filled with fair water (into which one peck of bran is put in a bag) and made pretty warm, the bran after yielding its flower must be taken out, and the Chymie, (Indigo Extract) mixed well with water in a Piggin, (a small pot) is put in according to the shade required, having first put in a hand-ful of powdered tartar; the cloth is to be well wet and worked very quick over the winch (stick on which it is hung) for half an hour. The liquor must not be made hotter than for madder red (just under boiling point). The hot acid of the vitriol would cause the blue to incline to green if too much heat was given. (From an old Dye Book).
6). To Make up a Blue Vat.—
Take 1 lb. Indigo thoroughly ground, put this into a deep vessel with about 12 gallons of water, add 2 lbs. copperas, and 3 lbs. newly slaked lime, and stir for 15 minutes. Stir again after 2 hours and repeat every 2 hours for 5 or 6 times. Towards the end, the liquor should be a greenish yellow colour, with blackish veins through it, and a rich froth of Indigo on the surface. After standing 8 hours to settle, the vat is fit to use.
7). Turquoise for Wool.—
Mordant with alum. For a pale shade use 1 teaspoonful of Indigo Extract (see [No. 2]) for 1 lb. of wool. Boil ¼ hour.
8). Blue for Wool. (Highlands).
Take a sufficiency of Indigo. (For medium shade about 1 oz. to every pound of wool). Dissolve it in about as much stale urine (about a fortnight old) as will make a bath for the wool. Make it lukewarm. Put in the wool and keep it at the same temperature till the dyeing is done. For a deep navy blue it will take a month, but a pale blue will be done in 3 or 4 days. Every morning and evening the wool must be taken out of the dye bath, wrung out and put back again. The bath must be kept covered and the temperature carefully attended to. Some add a decoction of dock roots the last day, which is said to fix the blue. The wool must then be thoroughly washed. This is a fast dye.
9). Indigo Vat. (For small dyers).
Add to 500 litres of stale urine 3 to 4 kilos of common salt and heat the mixture to 50° to 60°C., for 4 to 5 hours with frequent stirring, then add 1 kilo of madder, 1 kilo of ground Indigo, stir well, and allow to ferment till the Indigo is reduced.