Another process for CRIMSON.
When the silk is boiling in the soap-liquor, add one ounce of annatto, for every pound of silk, working it through the colander as directed, (page 136.) but without the composition or tartar: in some shades, however, both composition and tartar are admitted. The solution applied to cochineal with worsted has a considerable effect, changing it from a crimson, its natural colour, to a very bright fire colour; but it produces only a crimson when applied to silk; it gives, however, this colour a very beautiful tint; for, uniting with the tartar, it increases the effect without impoverishing the colour, and saving the annatto ground. Macquer.
Crimson by Brazil wood.
The silk should be first alumed, and then passed through a strong decoction of Brazil wood, half a pail to a pound of silk, which is to be worked, and put through an additional and strengthened dye of Brazil wood, and then washed off: if in hard water this will generally crimson the Brazil wood sufficiently; but if in soft water a little pearl-ash must be added; about one pound of the clear solution of pearl-ash, or rather the clear solution of a pound of pearl-ash, as one pound of water will not, we believe, dissolve a pound of pearl-ash: this is enough for forty pounds of silk.
The decoction of Brazil wood is prepared thus: one hundred and fifty pounds of Brazil wood chips are put into a copper which holds about sixty buckets of water; the copper is then filled with water and boiled for three hours, the waste by evaporation being occasionally supplied. The fire is now damped, the clear liquor drawn off, the copper filled again, and again boiled for three hours more. This process is repeated four times in all, when the dye of the wood will be fully extracted.
Logwood and old fustic are treated in the same manner, but only two boilings are required for these.
In regard to crimson generally, see forward, observations on dyeing silk crimson and scarlet, and also some observations on the dyeing of wool scarlet, page 85.
Of fine VIOLET.
For this colour the common boiling is enough, the silk is alumed the same as for fine scarlet, washed and twice beetled. Thus prepared, two ounces of cochineal are given to it, with the same precaution as usual, but no composition nor tartar. Being worked moderately warm, in working it must be expeditiously turned; after a quarter of an hour the liquor should be brought to boil, when the turning need not be so expeditious, but it should, nevertheless, be continued for two hours. After being washed the silk is dipped in the vat, more or less strong, according to the shade required.
Washing and drying are done in the same manner as for blues and greens, and in general for all colours dipped in the vat, namely, a small quantity at a time, in order that the silk may be kept open to the air, and that the greening of the vat may pass correctly and equally to blue. For some shades archil forms a part of this dye. For other violets on silk see Chapter III.