For 11 lb. silk add to a water 17 1/4 oz. sulphuric acid and 3 1/2 oz. solution of white soap. Stir well up and dye at 158° F. (70° C.) with 1 3/4 oz. aniline blue, which is added in 4 successive portions. Wash, brighten with vitriol sours, and rinse.
(1) On Old Mixed Silks (2 lb.). Boil out 25 dr. sumach in water, strain the liquid, and steep the goods overnight in the clear hot liquid. Take out the next morning, squeeze, and dye in a fresh cold beck of methyl green. If a yellower shade is required, picric acid is added.
(I) On Old Mixed Silks (2 lb.). Prepare and dye as in green (1), using cold solution of magenta instead of green.
(1) Take the silk through a catechu beck, weight for weight, if a good yield is desired. If a smaller yield is wished, less catechu is taken. Dye at a boil, lift, wring, and pass into a chrome beck at 6 3/4° to 8 1/4° Tw., and 77° F. (25° C.) If the shade required is very dark, the heat may be raised a little more. Wash well, make up a beck of fustic, extract of indigo, and orchil; add a little alum to draw on the fustic, and acidulate slightly with sulphuric acid for the blue. Dye at a boil, adding more of any of the colours as the shade may require.
(1) On Old Mixed Silks (2 lb.). Prepare as green (1), and dye to shade with a solution of methyl violet.
(1) Boil for 1/2 hour 11 lb. ground cochineal; filter, and set the clear liquor at 4° Tw. Add to the beck about 24 fl. oz. tin solution, and dye. It requires 24 hours to produce the scarlet. After dyeing, the silks are left wrapped up for 12 hours, rinsed slightly, brightened with citric acid, and dried. The solution of tin is made of 4 lb. muriatic acid, 2 lb. nitric acid, 5 lb. feathered tin, dissolved gradually in the course of a day.
(2) Prepare in stannate of soda at 4° Tw. in the cold; take through weak vitriol sours, and wash well. Give a second mordant of red liquor at 8 1/4° TV., thickened with calcined starch at the rate of 3 1/2oz. per 35 fl. oz. of the mordant. Dry without rinsing for at least 24 hoars; then rinse and dye with decoction of cochineal. When the colour is as deep as is required, add nitrate of tin to the same beck. This process gives scarlets as fine as (1), and with less loss of colouring matter. The object of the addition of calcined starch is to give the silk more body. In many dye works scarlets or silks are grounded with annatto.
(1) Aniline Violets. Acidulate the water very slightly with sulphuric add, and enter the silks. Begin to dye in the cold, adding the colour in small successive portions. Raise the heat gradually up to a boil to level the shade. If the tone is too blue, let the beck cool, and take the silks through again. They are then brightened by one or several successive passages through vitriol sours, and it must be remembered that heat increases the blueness and lessens the redness.
(1) The silk must not be washed, and a red shade is first given with annatto in a soap beck, not too strong. It is then washed and rinsed in the cold with sulphuric acid. The yellow shade is then given with picric acid, and the silk is dried without washing. For a heavier shade the process is the same, but turmeric is used instead of picric acid. The solution of annatto is made by boiling together for 1/2 hour equal weights of potash and annatto.