When it is wished to dye a regular series of scarlet shades in worsted, half the quantity or less, for some of the lightest, will be sufficient of the solution of tin, the tartar, the cochineal, &c. The worsted should be separated into divisions corresponding with the shades required; the lightest is of course to be done first: if any deficiency be in the shade, it may have another dip. This deficiency is easily perceived, and a very little practice will enable the operator to assort them perfectly.
It should be noted, that the vessel most proper to dye scarlet in ought to be made of block tin; such as are used by the scarlet dyers for the East India Company.
When woollen cloth is to be dyed scarlet, to every hundred pounds of cloth put six pounds of tartar and eighteen pounds of the solution of tin at first; the same quantity in the completion; and in each operation, six pounds and a quarter of cochineal.
For the accommodation of those who would make small experiments, one ounce of cream of tartar, six ounces of solution of tin, and one ounce of cochineal, may be used for every pound of worsted or cloth, putting two-thirds of the solution of tin and the tartar, and a quarter of the cochineal, into the preparation, and the remainder to the completion.
Observe, that although we have given processes for dyeing woollen cloth crimson as well as scarlet, yet crimson may be obtained in another way: for alum, the salts in general with an earthy base, and the fixed and volatile alkalies, possess the property of changing the colour of scarlet into crimson, the natural colour of the cochineal. The cloth which is dyed scarlet has only to be boiled, therefore, for about an hour, in a solution, more or less charged with alum, according as a deeper or lighter crimson is wanted. When a piece of scarlet has any defects, it is set apart for crimson. Soap and potash will also produce crimson from scarlet, but not of so bright a colour as from alum. Hence also we learn the necessity, in, at any time, working scarlet cloth, to avoid boiling it with soap or pot-ash, &c. if we desire the scarlet to remain.
To dye wool MAROON.
The worsted or yarn must be boiled for an hour or two in one twelfth its weight of alum and the same quantity of white argol. It is best, when there is a large quantity of yarn, to do this on the preceding day: if your copper hold a pack of two hundred and forty pounds, it will be cold enough to handle after remaining with the fire out during the night.
When the skeins, &c. are taken out and arranged upon poles or sticks, have a fresh water ready in the copper, into which put about thirty pounds of chipped peach-wood, and when it has boiled half an hour, pour in some water to cool it down, and add fifteen pounds of crop madder; work the yarn in this liquor rather under a boiling heat. When it is full enough, for some shades you must add archil. As the whole pack is dyed at four or five turnings in, some of the parcels may be varied in the hues instead of confining them all to one shade. The various turnings will take the greater part of the day to perform. When you choose to have as many shades as there are turnings in, you divide the drugs into different portions for different periods of the time, to be used according to the patterns required. The most economical method of using the drugs being to follow the patterns one after the other: practice will teach the operator to do this most advantageously.
More madder than peach-wood gives a lively red; more peach-wood than madder gives a bright maroon red, bordering on crimson, but more so without any madder; with the addition of archil it gives a crimson, but by no means to be compared with the crimson of cochineal. Urine with the archil renders a less quantity of archil necessary.