Scientific American 44, 14.7.1855
Black has been, by philosophers, denied to be a color, but it deserves to be called a color as well as brown. It is produced by the combination in excess of the three rays, red, blue, and yellow. To say that it is no color because it does not reflect light, la just as correct a piece of reasoning as to say "it is not light itself." Everything that we can distinguish by a quality of sight like a black piece of goods, independent of its form, may very correctly be called its color, as an artificial optical distinction.
Black Color on Woolen Goods.
A black color can be produced on woolen goods by dyeing yellow, red, and blue — the one on the top of another. Take five pounds of woolen goods, and dye then) a deep yellow, by boiling them in the liquor of 2 lb. of quercitron bark, and a pint of the spirits of tin (chloride of tin) in the boiler; this will dye a good yellow color. Take them out of this liquor, and dye them a deep red on the top of the yellow, by adding seven ounces of ground cochineal, 10 of cream of tartar, and half a plot of the chloride of tin to the liquor in the boiler. The goods are boiled in this for one hour, when they will he found a deep scarlet color. They are then lifted out of the boiler and washed thoroughly in cold water, and at last run through a tub of milk warm water containing a little urine, They are then washed again in cold water, and are tit to be finished in the boiler. This is done by simply milling them in a clear liquor containing good sulphate of indigo, which on white goods dyes a blue color, but will, when dyed upon the top of this scarlet-colored goods, produce a beautiful black. This color is too expensive to dye for common use; the method is merely given to show how a black can be dyed by using the very dye stuffs and processes for dyeing the three primary colors — red, blue and yellow. It is scarcely possible to give the exact quantity of the sulphate of indigo to produce the effect stated, but about one ounce to the pound of goods, if good in quality, is sufficient.
This receipt is very useful for the jobbing dyer, but not to the carpet or cloth dyer in the manufactory. When the jobbing dyer receives a red woolen shawl, or piece of red cloth to dye black, he can easily do this, by simply boiling it in a kettle with some sulphate of indigo. He can thus color such articles a good black, while he would utterly fail to do so by any other process. He may also dye old spirit claret colored dresses a good black in the same manner — simply boiling them in a solution of sulphate of indigo. Deep purple can be treated in the same way, and with the same results, only a little fustic or quercitron bark liquor should he added to that of the chemic (sulphate of indigo).
Iron Black.
For ten pounds of woolen goods, boil them for one hour in thirty ounces of copperas and ten of the sulphate of copper, with three pounds of rustic liquor. They are then taken out, aired and dripped. The kettle is then cleaned out, and the liquor of five pounds of good logwood into it, and the goods entered when boiling. They are kept boiling in this for one hour and half, when they should be a full black color. If they have a slaty appearance, they require more logwood; if they have a full brown rusty appearance, it is a sign they have received too much logwood. By running them through a sour of very dilute sulphuric acid some of the logwood will be stripped off, and the color will assume a clear good shade. Goods intended to be fulled with soap are dyed very full in color, as the fulling strips off some of the logwood. The old fashioned way of dyeing black, was to boil the goods in a very strong logwood liquor first, and in the copperas liquor last. By giving the stuffs two or more dips, the color is rendered more durable. The fustic is employed to throw the color on the jet shade. If this be left out of the bath, the color will be a blue black. Old dresses, coats &c., of various colors, such as greens, drabs and browns, may be dyed a good black by this process. Farmer's wives may dye their own stockings, &c., a good black by the method described. They must boil them well — not less than an hour — in both the copperas or mordant, and the logwood liquors. To prevent them crocking off, they must wash them well, and that in a strong solution of soap suds; after this they receive three or four rinsings in water.
By adding about one ounce of tartar to the pound of goods, in the preparation or mordant, and rinsing them in two cold waters after they have been boiled in the mordant — leaving out the fustic — and then dyeing, as has been described, with the logwood a beautiful blue black will be the result.
Ei kommentteja :
Lähetä kommentti