BLACK.
I. Chrome Black.—Black being the most difficult color to produce, as above remarked, the feathers require a specially careful preparatory treatment in order to remove everything that might interfere with the purity, uniformity and brilliancy of the color, or cause less dyed, dull spots and streaks. Naturally gray feathers, however, need not to be bleached or decolorized but only careful treatment and attention. The feathers are for twenty-four hours laid down in a solution of twice their weight of calcined soda, ammonia soda being preferable for this purpose to Lablanc soda (old process soda), then taken up and carefully rinsed clean from the alkaline in warm water, or better, in two warm waters. In the case of particularly valuable feathers it is recommendable, before laying them down in the soda solution, to rub the stains of the feathers off with a piece of carbonate of ammonia or with a large soda crystal. After rinsing, the feathers are entered for one hour, at 170° F., in a bath containing forty per cent., of the weight of feathers, chromate of potash, forty per cent. copperas, and twenty per cent. tartar, and several times turned and agitated during the specified period while the entering temperature is maintained. Then the feathers are taken up, and the adhering liquid squeezed out by hand or by rolling them through a clothes wringer with rubber roller. In the meantime a logwood bath of medium concentration is prepared either with a fresh decoction or with extract of logwood and twenty per cent. Marsailles soap dissolved in it. The feathers are entered in this bath at hand-heat, diligently agitated for twenty or thirty minutes and, if necessary, while the temperature is raised to 200° F., laid down in the bath until the correct shade and a level dye are obtained. The feathers are then lifted, squeezed, very thoroughly rinsed in cold water, passed through starch and dried with frequent shaking, respectively beating upon the board or between the hands.
It occurs sometimes, that the stems of the feathers are imperfectly died and present light brown or gray places. This is attributable to insufficient scouring. In this case the defective portions of the stems must be scraped with a sharp penknife and dyed over. This operation, however, is difficult and requires much practice and a light hand, as too much scraping removes the horny glossy surface of the stem and, when dyed over, the only change effected is, that a dull black mark takes the place of the discolored or brown spot. Often, however, the defect can be remedied by touching the imperfect portions up with a feeble alcoholic solution of shellac, in which some nigrosine is dissolved. With properly scoured feathers this mishap does not occur.
Another trouble, however, which is not unfrequent with blacks, is that the feathers are over-dyed and become brownish black instead of black. But in this case the remedy is as simple as its occurrence is frequent; a quick passage through sulphuric acid diluted with water to 2° B. strips off the excessive dye and produces a good color. Besides, this operation gives the feathers a brilliant lustre. Many dyers, therefore, methodically avail themselves of this effect of sulphuric acid and deliberately over dye their feathers (See IV below) and then apply the sulphuric acid passage for the purpose of imparting the feathers that peculiar lustre. A passage through a solution of sodium chloride, of 2° B. strength, has the same effect as a passage in sulphuric acid 2° B.
For this purpose lay the feathers down in the warm sodium chloride solution, until the black cotton strings with which the feathers have been tied together, as in the beginning described, begin to turn gray. Then take up the feathers, rinse them very thoroughly in cold water, drain, starch and dry.
Sodium chloride can be prepared in a simple way as follows: rub one-half pound fresh chloride of lime in a porcelain mortar with a little water into a smooth milk, which pour into a bucket, dilute with cold water, and add, under stirring, the solution of one pound Glauber salt; let settle and use the clear liquid. Instead of Glauber salt (sodium sulphate), soda crystals (sodium carbonate) may be used; the latter, however, is a little higher in price and renders the solution strongly alkaline.
II. Iron Black.—Lay down the feathers over night in a warm bath, in which one hundred per cent., of the weight of feathers, soda crystals have been dissolved. On the following day take them up, squeeze them out and lay them down for two hours in a proportionally strong solution of carbonate of ammonia, take them up and rinse well in warm water. Lay down for six hours upon a bath of nitrate of iron 10° B.; take up, rinse, and dye at 170° F. with the decoction of ten per cent. logwood in which five per cent. Marseilles soap has been dissolved. If a dead black is wanted, add some decoction of quercitron or turmeric to the bath. The desired depth being obtained, lift, rinse, starch and dry. In case the color is over-dyed, strip with sodium chloride (or sulphuric acid) 2° B., as above described, drain, squeeze and dry.
III. Logwood Black.—Scour and rinse the feathers well. Prepare a bath with three per cent., of the weight of feathers, carbonate of lime, six per cent. blue stone, and five per cent. tartar. Enter the feathers at 170° F., maintain this temperature for one hour; then let it go down, but leave the feathers in the bath for six hours longer, agitating them frequently during that time. Take them up, drain and squeeze, or centrifugate, and enter a handwarm bath containing some decoction of logwood, to which some decoction of fustic is added. Work for fifteen or twenty minutes, then raise the temperature to nearly boiling heat. Continue adding decoction of logwood, until a nourished black is obtained. This dye being hard to correct by the ordinary means, the additions of logwood decoction must be made with caution towards the end of the operation, in order to prevent over-dyeing. If a brownish touch is desired, add some more decoction of fustic when the black is nearly done. Then lift, rinse, starch and dry as usual under continual agitation, beating and shaking of the feathers. This chrome black is superior to iron black, because it imparts, to the ostrich feathers, more lustre.
IV. Whatever kind of feathers are to be dyed, white, grays or old blacks, wash them perfectly clean in two or three warm soap baths and remove the soap by rinsing in two or three warm and several cold waters. Colored feathers which are to be redyed blacks must be stripped of their color as much as possible by washing in hot soap to which some ammonia is added, whereupon this must be rinsed in several waters absolutely clear from soap and alkali; it is an erroneous notion to neutralize the last trace of alkali which may remain, by a passage through a feeble acid bath. The feathers thus prepared for dyeing, make a bath of two parts nitrate of iron to one part hot water at 170° F., enter the feathers, work them through a few times, and then lay them down in the bath for twelve hours (over night). Then lift and rinse the feathers in several (three or four) cold waters Prepare a pretty strong decoction of logwood and fustic, for which take two parts of the former to one part of the latter; let the temperature go down to about 208-210° F., when enter the feathers and maintain that temperature for fifteen or twenty minutes. Then shut off the steam or remove the dye-vessel from the fire, as the case may be, and let the feathers cool in the bath. When cold take them out, prepare a fresh bath of logwood and fustic like the first, enter the feathers at 208-210° F., after fifteen or twenty minutes add about a teaspoonful of copperas for one gallon of water, and leave the feathers in the bath for six or eight hours longer; then lift and rinse in several cold waters. The feathers are at this stage black with a strong brown touch which is removed by a cleaning bath of Eau de Javelle (sodium chloride). The latter is prepared by rubbing one-quarter pound chloride of lime to a smooth milk with a little cold water (in a porcelain or a marble mortar) and adding this milk to the solution of one-half pound Glauber salt in three parts water. After good stirring the mixture is then allowed to settle, when the clear solution is poured off and put up for use in well stoppered bottles. Of this liquid so much is added to a basin or pan full of warm water that it gives a slippery feel between the fingers, similar to that of a solution of soda.
In this bath the feathers are agitated for six or eight minutes, or until the liquid has assumed a yellowish color. Then the feathers are taken out, rinse in two or three warm waters, passed through raw starch, pressed out between several laps of a clean piece of muslin, and dried either by rubbing them in pulverized and sifted potato starch or by shaking them before an open fire or gas-flame.
The nitrate of iron bath can be preserved and used for the same purpose for eight or ten days, but the first logwood bath becomes useless and is let out. As above observed (I) sulphuric acid can also be employed for correcting the over-dyed feathers and reducing that brownish color to a pure lustrous black, but a much shorter passage is given: the feathers are entered by single strings, well opened, agitated in the sulphuric acid bath for a few seconds, and immediately rinsed. Where week work is done, it is advisable to have two men employed at this operation, one of whom passes the feathers in the acid bath and hands them over to the other man for rinsing.