A Book on Vegetable Dyes

by Ethel Mairet

QUERCITRON.

Quercitron is the inner bark of the Quercus nigra or Q. tinctoria, a species of oak growing in the United States and Central America. It was first introduced into England by Bancroft in 1775 as a cheap substitute for weld. He says, "The wool should be boiled for the space of 1 or 1¼ hours with one sixth or one eighth of its weight of alum; then without being rinsed, it should be put into a dyeing vessel with clean water and also as many pounds of powdered bark (tied up in a bag) as there were used of alum to prepare the wool, which is to be then turned in the boiling liquor until the colour appears to have taken sufficiently: and then about 1 lb. clean powdered chalk for every 100 lbs. of wool may be mixed with the dyeing liquor and the operation continued 8 or 10 minutes longer, when the yellow will have become both lighter and brighter by this addition of chalk."

Quercitron for Silk. Bancroft.

1 to 2 lbs. of bark to every 12 lbs. silk according to shade required. The bark, tied up in a bag, should be put into the dyeing vessel whilst the water is cold, as soon as it gets warm the silk, previously alumed, should also be put in and dyed as usual. A little chalk should be added towards the end of the operation. A little murio sulphate of tin is used where more lively shades of yellow are wanted.

Boil at the rate of 4 lbs. bark to every 3 lbs. of alum & 2 lbs. murio sulphate of tin with a suitable quantity of water, for 10 to 15 minutes. Reduce the heat so that the hand can bear it, put in the silk and dye till it has acquired the shade. By adding suitable proportions of sulphate of indigo to this yellow liquor and keeping it well stirred, various and beautiful shades of Saxon green may be dyed.

By dissolving different proportions of copperas or copperas and alum in the warm decoction of bark, silk may in the same way be dyed of all the different shades of olive and drab colours.

For Cotton and Linen. Soak the yarn in a liquor made by dissolving ¼ of its weight of alum in the necessary water, to which it will be highly advantageous to add at the rate of 1 lb. potash or 10 oz. chalk for every 6 or 7 lbs. alum. The yarn is taken out and dried well: being afterwards rinsed, it is to be dyed in cold liquor made by boiling 1¼ lbs. of the plant for each lb. of yarn, which, after having received a sufficient body of colour, is to be taken out of the dyeing liquor and soaked for an hour and more in a solution of sulphate of copper (blue vitriol) containing at the rate of 3 or 4 oz. for every pound of yarn: it is then removed without being washed, put into a boiling solution of hard soap, containing 3 or 4 oz. soap for each pound of yarn. Stir well and boil for about ¾ hour or more. Then wash and dry.

And again, take a sufficient quantity of acetate of alumina. This is made by dissolving 3 lbs. alum in a gallon of hot water, then adding 1 lb. sugar of lead, stirring well for 2 or 3 days, afterwards adding about 2 oz. potash and 2 oz. powdered chalk, (carbonate of lime), mix with warm water and soak linen or cotton well in this for 2 hours, keeping warm; squeeze out, dry; soak again in mordant, squeeze; dry; soak in lime water, dry; this mordanting and liming can be repeated if a fast yellow is required: it should then be well washed. 12 to 18 lbs. of Quercitron bark, for every 100 lbs. cotton or linen, is tied up in a bag and put in cold water, and slightly heated. The cotton is put in, stirring for an hour to an hour and a half while the water gets warm: then the liquor is heated to boiling point and the cotton boiled a few minutes only. Slow raising to boiling point gives the best colour. Instead of using acetate of alumina, the cotton can be impregnated with some astringent such as galls or myrobalans (1 lb. in 2 or 3 gallons of water with a little soda). Macerate the cotton an hour or two in this and dry, then a solution of alum (8 lbs. alum, 1 lb. chalk, in 6 gallons of water) soak cotton 2 hours, and dry, then soak in lime water and dry. Second time in alum and dry. Then wash and dye slowly in the Quercitron. This is a lasting yellow for cotton or linen.

OTHER YELLOW DYES.

"Root of the dock, bark of the Ash tree, leaves of the almond, peach and pear trees, all give good yellow dyes, more or less fine according to the time they are boiled and in proportion to the Tartar and alum used. A proper quantity of alum brings these yellows to the beautiful yellows of the weld. If the Tartar is in greater quantity, these yellows will border on the orange, if too much boiled they take brown shades." From a dyeing book, 1778.