Chapter V: ON DYEING SILK AND COTTON BLACK, &c

_To dye silk black for velvets—To dye silk black, London process—On dyeing cotton black at Rouen—To dye cotton black, London process—For dyeing black, particularly cotton velvets, at Manchester—On dyeing silk and cotton black, with a blue ground—Another iron liquor—To dye cotton black, by using the preceding solution—To dye cotton violet—To dye cotton red—To dye cotton an Adrianople or Turkey red—Miscellaneous observations relative to Adrianople red._

Some of the more simple and less difficult processes of dyeing both _cotton_ and _silk_, are described in the preceding chapters; we shall now describe those, not only for black, but for some other colours, which require more care and attention. _For ungumming and boiling silk, &c. see Chap. VI._

Silk has a strong affinity for galls, and advantage is sometimes taken of this: for silk, being a valuable article, is often galled to excess, merely to increase its weight.

Cotton has a strong affinity for iron, and iron has the same for _gallic acid_, wherever it may be found; therefore, in sumach, alder-bark, &c., iron unites with the acid, whenever both are connected by the medium of water. _Tannin_, doubtless, has also some share in such dyeing processes, although what does not even now appear to be well understood.

Black, MACQUER observes, is rather difficult to be dyed upon silk; or, at least, there is reason to think so, from the numberless experiments which have been found necessary to the attainment of a good black, as well as from the multitude of heterogeneous ingredients which Macquer admitted into the composition of his various processes for this dye, some of which consisted of arsenic, corrosive sublimate, litharge, antimony, plumbago, and about ten other ingredients! we shall not, therefore, detail such preposterous mixtures; one, however, we may just put down by way of showing what the art was in Macquer's time.

Take twenty quarts of strong vinegar, one pound of black nut galls pounded, and five pounds of iron filings; these ingredients are to be mixed in one vessel.

_To dye skein silk_ BLACK _for velvets, Genoa process, (from Macquer.)_

The silk should be ungummed by boiling it four hours with a quarter of its weight of white soap, and afterwards to be well cleared from the soap.

Take, for every hundred pounds of silk, twenty pounds of galls in powder, and boiled one hour; two pounds of sulphate of iron; twelve pounds of iron filings; and twenty pounds of gum arabic or senegal.

This process is very simple: here are the gallic acid and tannin of the galls, and the iron of the sulphate and the filings. But we must proceed to a more modern process.

_To dye silk_ BLACK, _the London process._

Take of wove silk, _twilled sarsenet_, one hundred and fifty yards. Boil, for three hours, of alder bark one bushel and a half; of logwood fourteen pounds; and of iron filings one pound. Then let the fire be damped; dissolve four ounces of sulphate of copper in water; wet out the silk in hot water; after which put the solution of sulphate of copper into the liquor and stir it only; then put the silk into the copper, and work it from end to end four times; after which take it out in the air; now put it in again and work it as before; take it out again and let it be aired on the floor, opening it from time to time till it is cold; repeat the same thing twice more, in all _four times_. This is termed four wets. While the last wet is cooling and airing, dissolve and put into the copper three pounds of sulphate of iron, and then give the silk two more wets, which make the number of wets six. The drugs are now left to boil as much as they will during the night, being left so to do, because in a large business, this part of the process would close the day's work.

The next morning give the silk four or five wets more, and leave it in the copper all the following night, observing when it is left in, and always when it is worked in, that the heat, must be considerably under the boiling point, and the silk kept covered by the liquor: for _if any part be exposed to the air it will be marked_.

_On dyeing cotton_ BLACK _at Rouen, (from D'Apligny.)_

Take one hundred quarts of sour wine, bad vinegar, or small beer; put to either of these twenty-five pounds of old iron hoops rusted by the air or dew; twelve pounds of rye meal or coarse bran; put the whole into a copper and heat it rather more than blood warm. In the summer it would do exposed to the sun and air with a porous cloth over it, to let in the air, but keep out dirt, &c.; the older this solution is the better; but it should be at least _two months old_.

Cotton skeins are galled by being worked in a solution of galls; alumed and then dyed in weld liquor; this in the result is yellow; they are then passed through a decoction of logwood, and after that of sulphate of iron, a quarter of a pound to every pound of cotton; they are then dyed in madder, half a pound to every pound of cotton.

We cannot recommend this process, although we give it, as much better methods are now known.

_To dye cotton_ BLACK—_the London process_—_used by various calico printers in the suburbs._

Cotton cambric piece-goods are passed through a blotching machine to receive a mordant of acetate of iron, and galled slightly; sumach is used instead when galls are dear; the cotton is then passed through logwood, or logwood and fustic, and then through sumach; so that it is possible thus to give them the mordant sufficiently in proportion to the iron liquor at first; proceed as in dyeing afterwards, at a heat approaching boiling or even boiling. You may now proceed by adding first the galling or sumach slightly; afterwards the logwood, &c.; and then the remainder of the galling or sumach may be used to finish it; and thus dye the goods black by the quickest possible process.

It should be observed respecting the last process and the process which precedes it, that in dyeing black alum is inimical to the colour. Therefore D'Apligny's is not now esteemed. Alum for black is as improper, as it is proper and essential for red and yellow.

In regard to giving the acetate of iron for black at once, as the second, or _London_ process directs, it may be done by having the proportions full; by _full_ is meant that the mordant should be full enough; then, after the slight galling, as directed in giving the logwood and alder bark decoction, or logwood and fustic, be sure to have that decoction strong enough. This might be called the ground; and the most perfect judgment might be formed of it by having a part of a piece, or one piece of a batch dried in the stove: for, according to the fullness of the ground, so will the black be rich and perfect or otherwise.

The alder bark and fustic are used only to prevent the hue of the logwood from being predominant. If the ground be a full and rich brown, the second full galling or sumaching will bring it to a full and rich black; but, if the ground be poor, these processes will cut or destroy the ground, and the black will be foxy, nasty, and poor; and not only so, but the material dyed will soon wear rotten, because having an over-dose of iron, the iron will tend to decompose the cotton. Therefore the following process is most esteemed.

_For dyeing_ BLACK _(particularly cotton velvets) at Manchester._

In a large dye-house where much business is done, a great many wine-pipes or other large tubs, or any substitutes are arranged in an appropriate place. Into these are put old iron hoops, rusted in the air, and cut into short pieces; a layer of the iron pieces and a layer of the alder bark, again a layer of iron and a layer of the bark, and so on in succession from the bottom to the top. When the pipes are all thus filled, water is poured into them till they are filled up; they remain in this state for six weeks or two months according to the season, whether summer or winter.

The same process will do for any other cotton goods as well as velvets, such as calicoes, cambric, and jaconot muslins, cotton in the skein, &c.

In some cases there are persons who pass the goods through the _liquor_ of the aforesaid black vat. The colour of this liquor when it is fit for use is purplish, particularly after being once used and returned to the vat again, which it always is. Others begin by passing the goods through a decoction of logwood and sumach, then through sulphate of iron, then wash off through logwood only; then through sulphate of iron; always washing off from this last; the goods are then dried, and this is called the _first time of saddening_.

They are next passed through logwood, then through sulphate of iron, then washed off, then again through logwood, then sulphate of iron, and then washed off; and then dried. This is called the _second time of saddening_.

Supposing the goods to consist of a hundred or a thousand pieces, after drying the second time they are brought in lots to the foreman for examination, and assorted into lots one, two, and three. All that is fit for lot one is full enough and has ground enough, and is of a rich full-bodied brown, ready for galling or _sumaching_: sumach being the substitute for galls, this process is termed in the dye-house, _macing_. Lot two is not full enough, and must pass through logwood, then sulphate of iron, and then be washed off. Lot three is still more deficient; this must be passed through logwood and the sulphate of iron twice and then washed off, and both lots two and three dried again.

Lot one is now to be sumached for the _first_ time: that is, passed through a decoction of sumach, then through sulphate of iron, and then washed off: if the decoction of sumach be kept up strong after all of them are once sumached, they may be dried. Lots two and three, when they are dry, are also to be sumached the same as lot one, and dried.

As soon as any of them are dry they are ready to be sumached the _second_ time by passing them through the decoction as before; but instead of sulphate of iron, some of the alder bark and _iron liquor_ are used; or as we shall term it, the _liquor of the black vat_. They are then to be washed off and dried. If the black liquor and the sumaching be powerful, some of the goods will be finished when dry. Such are examined by the foreman; those which are not finished must go through the last process again. The finished goods are well and repeatedly washed off in fresh clear soft water two or three times and then dried.

The _cambric muslins_ are sent to be calendered to imitate silk sarsenets.

_Book-muslins_ must be sent to the muslin dressers, except where, in some cases, they sarsenet and dry their own goods.

By the above method the ground is secured, and so is the black, and also the strength of the goods.

_On dyeing silk and cotton_ BLACK _with a blue ground._

It is remarkable, that although an indigo ground for wool enriches the black, yet for silk and cotton it is not generally considered necessary. Latterly, however, we believe the dyers of black on cotton do first give it an indigo ground before the black is given. This is, nevertheless, not a new method, for D'Apligny describes the process in his Art of Dyeing, _for linen and cotton yarns_; these are first dyed sky-blue in the vat, then wrung out and set to dry. They are galled in the proportion of one part galls to four of yarn, being left twenty-four hours in the gall liquor, wrung out anew, and set to dry: about ten pints of iron liquor to every pound of yarn are then poured into a tub, in this the yarn is turned on sticks, and worked with the hand for a quarter of an hour, it is then wrung out and aired. This operation is twice repeated, adding each time a new dose of the iron liquor; the yarn is aired once more, then wrung out, well washed, and dried. To complete the dyeing of the yarn a weight of alder-bark equal to that of the yarn is boiled with a sufficient quantity of water for an hour; to this is added one half of the bath which has served for the galling and sumach. The whole is boiled for two hours. When cold the yarn is put in and worked, aired occasionally, and then left in the bath for twenty-four hours, when it is wrung out and dried. To complete it, it is steeped and worked in the residue of a bath of weld, to which a little logwood is added; it is then taken out, wrung, and immediately passed through a tub of warm water, into which one part of olive oil to sixteen of yarn has been poured. It is finally wrung out and dried. See URE'S _Berthollet_, vol. ii. page 18.

_Another iron liquor; pyrolignite or acetate of iron._

Although we have described an _iron liquor_ in a preceding section, it may be useful to give the following process for another here. Fill a cast-iron boiler with pyrolignous acid, add to it old iron well oxidized, and boil. The solution of the oxide will take place rapidly. When the iron grows clean, and the solution black as ink, throw the whole into a cask, to be employed as occasion shall require.

_To dye cotton_ BLACK, _by using the preceding solution._

Prepare the cotton as usual, by giving it a blue ground; gall it, and pass it through a bath of the solution of pyrolignite of iron diluted with lukewarm water. Renew the gallings and the passings through the bath of pyrolignite of iron till a deep and brilliant black is obtained. Finish by passing the cotton through olive oil thus: throw on some lukewarm water a little olive oil, pass the cotton through it; the cotton absorbs the oil, but it must be worked a long time in the bath to diffuse the oil equally. Dry in the shade. The cotton is now a perfect and very durable black.

Every time the bath of pyrolignite is used, what remains must be thrown away; the old baths are never added to the cask.

The application of oil, which heightens the black, and imparts softness to the stuffs, is given to such articles as cotton velvet by means of brushes, which are slightly imbued with it. _Berthollet._

We may add here, that an iron liquor called _tar-iron liquor_, prepared from the acid obtained from tar, (the acetic acid we presume) is now well known in commerce, but we have not room, nor does it appear necessary, to describe the method of making it; it is much used in preparing mordants for black and other colours by the dyers and printers of silk. This iron liquor may be obtained of Blake, North Street, Back Church Lane, St. George's in the East, London. See _M'Kernan_.

_To dye cotton_ VIOLET.

Pass the skeins through the black vat and dry them, then pass them through a decoction of galls and dry them again, then through a decoction of logwood, then of alum and verdigris, washed off, and dried.

Or thus: by the black vat liquor, that is, the liquor of old iron and alder bark in some cases. Let the vat liquor be prepared from the iron hoops, vinegar, rye, or coarse bran, described in page 108. By this liquor it is easy to procure all the violet shades from the pansy flower up to the lilac and violet.

The goods must be first blue-vatted and dried, then galled and dried, then passed through the iron liquor, then maddered, then washed off, and dried; the liquor must always be kept much below a boiling heat, as this heat makes the colour obtained from madder brown: whatever drugs require boiling must be prepared by a decoction previously made.

For some shades sulphate of copper is used; for others verdigris, saltpetre, and alum.

To dye to the pattern the preparations should be always of one given strength, and all solutions of mordants the same. The time of working the goods in the dye must be regulated by the fulness or lightness of the pattern; and the quantities of the various drugs, &c. used much or little accordingly, reserving patterns of processes, with the particulars of such processes noted down. In proportion to the number of these upon record, and with strict attention to the subject, a good pattern dyer is formed. Time and practice are, however, absolutely necessary, with a delight in the business: for without a pleasure in dyeing no one can become a good or an eminent dyer. In many of the branches of this art there are, it is true, labour and pains in abundance; but there is also a portion, and that not a small one, of pleasure in others, which will counterbalance the care, anxiety, labour, and fatigue inseparable from this useful and important occupation, and which so strikingly exhibits the science and ingenuity of man.

_To dye cotton_ RED.

If the cotton skein has not been cleansed since it was spun it must be cleansed by being boiled in a solution of potash, one ounce of which, if good, to a pail of water may be enough, or more than enough. The cotton must be put into bags when boiled, then washed off and passed through clean water, scoured with a little sulphuric acid, and then washed off again; then galled, washed off, and dried. The galls should be white galls: for twenty pounds of cotton five pounds of bruised galls are boiled in about one hundred and twenty quarts of water for two hours.

After galling, the cotton must be alumed: four ounces of Roche alum for every pound of cotton. When alumed it must be washed off and dried.

The cotton is now to be dyed in a copper containing six pounds and a quarter of best crop madder, with a sufficiency of water. The heat is kept under that of boiling for three quarters of an hour. After being aired, washed, &c. it is put in, worked, and boiled for twelve or fifteen minutes. Some dye it again two days after, because the longer to a certain degree between aluming, dyeing, and drying, and between one dyeing and another, the better. The second time of dyeing eight ounces of madder are used for every pound of cotton. Some dyers gall it twice, and consequently dry it as often, then dye it at once in the madder, having a proportion accordingly. This is a red full-bodied colour.

_To dye cotton an_ ADRIANOPLE _or_ TURKEY RED.

For one hundred pounds of unbleached cotton, take the following articles and pursue the described processes.

Lixivium No. 1. Dissolve one hundred and fifty pounds of alicant soda, (barilla) in three hundred quarts of river water. There must be no more water than enough to dissolve the salt. An egg must float on it or it will not be strong enough.

Lixivium No. 2. One hundred and fifty pounds of fresh wood ashes, and three hundred quarts of water.

Lixivium No. 3. Seventy-five pounds of quicklime, and three hundred quarts of water.

The cotton is to be boiled three hours in a liquor composed of equal parts of each of the above solutions, taken from them when clear and in a settled state. The liquor must be replenished occasionally, so that it shall always cover the cotton during the whole time it is boiling; after which it must be taken out, washed, and dried in the air.

Into one hundred and thirty quarts of a mixture consisting of equal parts of the above three lixiviums, put twenty five pounds of sheep's dung and part of the intestinal liquor, previously well mixed by means of a wooden pestle, and the whole strained through a hair sieve. Then twelve pounds and a half of good olive oil is poured into the mixture, when it instantly forms a soapy liquor.

Into this liquor the cotton should be worked hank by hank, often stirring it; the cotton, after all the hanks have been worked separately first, is then left in the liquor for twelve hours; it is then taken out, lightly wrung and dried. The liquor is put by for brightening. This process is repeated three times during the working; and by the time the solution is all worked four hundred quarts might be used, but that will not injure the clear of it from being applied in brightening; and it must be reserved for that purpose.

When the cotton has been three times dipped in this soapy water, and three times dyed, the same process is repeated, except that the sheep's dung is left out; the liquor is also preserved for brightening. The cotton, having gone through these processes, should be as white as if it had been bleached.

When dry it is to be galled, using a quarter of a pound of galls to every pound of cotton; after this it is dried, then take six ounces of alum for the first aluming; it is then to be dried again, and to hang three or four days in the air, and then, when dry, to be alumed again; four ounces of alum, and four of the lixivium may be added to the last alum water.

The madder used for this red is called _lizary_, which furnishes a dye incomparably finer than that produced by any other madder. Of lizary madder, therefore, take two pounds for every pound of cotton, and twenty pounds of liquid sheep's blood well mixed with the water in the copper before the madder is put in. The butcher should stir the blood to prevent its coagulating; the copper should be carefully skimmed; the madder should not boil, but be brought during the process from blood-heat to within a few degrees of the boiling point: if it boil at last, as some prefer it, it should only be for a few minutes.

In order to brighten the colour, the cotton is dipped in a lixivium of fresh wood ashes, and five pounds of _white_ soap: yellow or mottled soap is improper. When the cotton has been well worked in this liquor, it is, with the liquor itself, put into a copper sufficiently large to hold it with some addition of water, and made to boil over a slow fire, for three, four, or more hours. The liquor must be covered with coarse white linen cloths, to keep as much steam in as possible.

Some of the skeins of cotton must be taken out from time to time, and washed perfectly; when the red is judged perfect and sufficiently bright, the fire is withdrawn.

If instead of the wood-ash lixivium and soap, the two reserved liquors and soap are used, the red will be much brighter than the finest Adrianople carnation.

_Miscellaneous observations relative to_ ADRIANOPLE RED.

In regard to the above processes, we may observe, that those given for Adrianople red in _Ure's Berthollet_, are more numerous, being regularly numbered to the _seventeenth_, or last operation called _brightening_. After a careful attention to those processes we see no reason to alter our own, yet we nevertheless advise the dyer to become acquainted with what is stated in that work, many details being there given for which we have not room, particularly for making _different shades_ of the colour. We add, however the following from vol. ii. p. 140.

"Cotton dyed red, may, moreover, be made to pass through all the shades, down to the palest orange, thus: pure nitric acid is diluted with two-fifths of water; chips of tin are oxidized in it till the liquor grows opal; the solution is employed at different strengths; the colour varies according to the concentration of the solution: when it is strong, shades are obtained which have some relation to those of scarlet.

"In general, when brilliant colours are desired, we must not charge them too much with oil; we must give feeble leys long repeated, charge little with alum, employ the best madders, and, at last, brighten powerfully without sparing soap."

We have directed _good_ olive oil; but M. VITALIS directs fat oil, (_gallipoli_) to be used in the processes for dyeing Adrianople red, and Berthollet says, it must not be a _fine oil_, but one containing a strong portion of the extractive principle.

A factory for dyeing this red was first established in this country in 1790, by M. PAPILLON, who obtained a premium from the Commissioners and Trustees for Manufactures in Scotland, for communicating the details of it on condition it should not be divulged for a term of years, during which _M. Papillon_ was to have the sole use of his secret. This term being expired the process was published. See vol. xviii. of _Tilloch's Magazine_.

M. VITALIS, (in his work on Dyeing published in 1823) has given, at length, the _mode of dyeing Turkey red at Rouen_. It differs in many particulars from Berthollet and others. We learn from him that two systems for imparting this colour are in use at Rouen. The first is called the _grey course_ from the cotton being subjected to the maddering immediately after it has received the oily preparations, and the mordants of galls and alum which give it a _grey_ colour. The _yellow course_, is so called from the cotton, after having received a first time the oily preparations, as well as the mordants of galls and alum, _not_ being exposed to the maddering till it has passed a second time through the same preparations, and the same mordants which give it _a yellow_ colour. This second manner of working the Turkey red is called, in the dye-house, _remounting on the galls_. Dr. URE, in a note to Berthollet, vol. ii. p. 378, has detailed these two courses, and made, besides many valuable observations on them, and the dyeing of Adrianople red generally, for which we must refer to the work, as our limits prevent the possibility of any further notice of them here, except to add, that a _process for dyeing cotton of a smoke red_; and another for _dyeing cotton a cherry red_, is well deserving the attention of the dyer.

In regard to the _blood_ used in dyeing Adrianople red, Dr. Ure decidedly affirms, that "_it adds no colouring matter to the madder in the dyeing operation_;" in this he is countenanced by the observations of Chaptal, see Berthollet, vol. ii. p. 141. "To the use of blood in the madder copper," says Dr. Ure, "I attribute nothing, as from the rancid and putrid state in which I have seen it used, were it not for the prejudice of the operator, it might be safely dispensed with." A very eminent calico manufacturer, whom Dr. Ure consulted, assured him, that in the Turkey red process the only essential mordants were oil and alumina; and that bright and fast reds, equal to any produced by the complicated processes of sheep's dung, galls and blood may be obtained without those articles.

We make no comments on these observations, but leave them to the good sense and intelligence of the dyer: they deserve the utmost attention.

_Linen yarn_ takes a colour almost as brilliant as that of cotton, but it must be passed through a double number of oils and leys. The latter must even be very strong, otherwise the oil flows out at the surface. The greatest attention must be bestowed on the scouring out first: for the yarn mingles and entangles by the heat to such a degree, that it sometimes can be neither dipped nor unravelled.

It should be mentioned that the large dyers of Adrianople red, now obtain their soda for lixivium No. 1, by using common salt in solution, to which is added a solution of pearl-ashes. On boiling these together a muriate of potash is formed, which is taken out of the liquor with a skimmer; a _carbonate of soda_ remains dissolved in the liquor, and is, of course, applied to the same purpose as, and at a much cheaper rate than, the Alicant soda.