The Dyer's Guide / Being a compendium of the art of dyeing linen, cotton, silk, wool, muslin, dresses, furniture, &c. &c.; with the method of scouring wool, bleaching cotton, &c., and directions for ungumming silk, and for whitening and sulphuring silk and wool; and also an introductory epitome of the leading facts in chemistry, as connected with the art of dyeing

CHAPTER IV. ON SCOURING AND DYEING WOOL.

On the action of alum and tartar upon wool—A pastil or woad vat for blue—To prepare the indigo mentioned in the preceding directions—Rules to judge of the state of the vat—Indications when a vat has had too much or too little lime—To work a vat which is in proper order—On the putrefaction of the woad vat—Methods of dyeing blues—To dye wool, with lac-dye, scarlet, or crimson—To dye worsted yarn a crimson—A preparation of archil to finish the crimson—On dyeing wool scarlet—To dye wool maroon—To dye wool yellow—To dye wool brown or of a fawn colour—To dye wool purple, &c.—To dye wool green—A chemic vat for green woollen—A chemic vat for blue woollen—To dye wool orange, gold colour, &c.—To dye wool black—another process for black without a blue ground—To dye wool grey—Mixture of black or grey with red and blue—On browns, fawns, greys, &c.—On the yellow of quercitron bark—On a full bright yellow from the same bark—Bancroft's murio-sulphate of tin—To dye wool buff—To dye wool peach—To set an Indigo vat for worsted, serge, &c.

Wool is usually scoured for being dyed with stale urine, the staler the better: it is used in the proportion of one part to three parts of water, full as hot as the hands can bear when the wool is worked about in the fluid.—If the wool be in the fleece, what is called its natural yolk, and which is said to preserve the wool from the moth, is of a greasy nature, and is scoured out by the volatile alkali in the urine. If the wool be in the state of spun yarn it has gallipoli, or rape oil, in its thread, the spinner, or rather the comber, using it to render the wool more flexible, &c. It is absolutely necessary that wool, (as indeed every other material to be dyed) should be made very clean and white, if any brilliant or bright colour is to be imparted to it. For this reason it is that the wool is passed two, three, and in some instances even four times through fresh scouring liquors; in the last, and sometimes in that which precedes the last, soap is used in the proportion of from seven to fourteen pounds, and in some instances to twenty one pounds or more, to, a pack of two hundred and forty pounds of wool, according as it is fine or coarse: for superfine colours more than common is used. Worsted requires less than coarse yarn, having less grease and dirt in it.

It ought, however, to be known, that boiling wool for a long time in any alkaline liquors, or a liquor made of soap, tends greatly to the decomposition of the cloth; indeed long boiling in any strong alkaline ley converts wool into a kind of soap, and, hence, it is easy to see why such processes injure wool or cloths made with it.

The preceding observations apply to the alkalies in a caustic state, or in the state of carbonate, not when they are neutralized by powerful acids: for wool, when fit to receive the dyes, and if it is designed to be dyed yellow, should boil two hours with one-twelfth or one-tenth of its weight, of sulphate of alum (common alum) observing proper precautions, and the use of a sufficient quantity of prepared weld plant boiled, &c.: or of quercitron bark, as will be shown in the processes of the different yellows. If it were yarn, and the threads cut in two, it would be found dyed throughout, and of a body and richness in proportion to the correct application of the various ingredients, and with due regard to time, weight, measure, &c.

In the process just mentioned, we may observe, that the quantity of alum and of the weld plant used will be found very considerable: from one twelfth to a fourth of alum, and, according to the French method, four or five times more weld than the quantity of the wool.

When a process of dyeing has been scientifically conducted, the wool will take so much of the alum that the bath will hardly taste of it; and afterwards take the colour of the dye bath out of it; so that the remaining liquor put into a glass will be nearly like water.

The action of alum and tartar upon wool.

From the experiments of Dr. Ure, (Notes to Berthollet, vol. ii. p. 323.) it appears that alum has the property of increasing the solubility of cream of tartar; that as, in using alum and tartar, the wool is impregnated with alum and a large quantity of tartaric acid, these two salts should never be employed together, except when the colour is susceptible of being heightened and rendered brighter by acids, as is the case with cochineal, madder, and kermes. On the contrary, alum should never be employed for wools intended to be dyed with woad, or Brazil wood, the colour of which is easily destroyed or altered by acids.

To conclude these preliminary observations, wool has a strong and powerful affinity for all dyeing materials; and, therefore, the processes for dyeing wool are, in general, by no means so complicated as those for dyeing cotton, silk, &c.; although some colours, even to these, are readily, and without a complication of processes, imparted.

A pastil, or woad vat for BLUE.

Take, upon as small a scale as can conveniently be tried, a copper vessel, which will contain about twelve gallons, two thirds full of soft water, and one ounce of madder. Fix this small copper in a larger copper of water, so that the heat may be applied to keep the liquor in the smaller copper at a proper temperature; it will be then, in fact, a water bath.

Having kindled the fire in the afternoon, put in a good handful of bran and five pounds of woad; at five o'clock in the evening let it be well stirred and covered over, the liquor being about blood-warm; let the same heat be continued as nearly as possible, at least so as not to be lower than summer heat by the thermometer, nor higher than fever heat by the same instrument. The vat must again be well stirred at seven, at nine, at twelve at night, at two in the morning, and at four. Hellot, describing this process, observes, that "the woad then working, some air bubbles began to rise pretty large, but few in number, and of a very faint colour; it had then two ounces of lime added, and was stirred; this was four o'clock in the morning; at five a pattern was put in, and at six it was taken out and the vat stirred. This pattern had received some colour. At seven o'clock another pattern was put in, and at eight it was stirred again. The second pattern was tolerably bright. An ounce of prepared indigo, (see p. 75.) was then added; at nine o'clock another pattern was put in; at ten it was stirred again, taking the pattern out, and putting in an ounce of lime because it began to smell sweetish; at eleven another pattern; at twelve at noon it was stirred again. This process was continued till five o'clock in the evening; then were added three ounces of prepared indigo; at six another pattern was tried, and at seven it was stirred again; the last pattern came out of a very good green, and became a bright blue. One ounce of lime was added to sustain it till nine o'clock the next morning; patterns were put in from time to time: the last was very beautiful. The vat was then filled up with water and a small quantity of bran and stirred; after which patterns were tried every hour till five o'clock in the evening, when, being in a proper state, it was immediately worked. Some lime was then added to preserve it; it was stirred and left to another opportunity to reheat."

To prepare the indigo mentioned in the preceding directions.

Boil, in a gallon of water, for three quarters of an hour, two ounces of pot-ash, three quarters of an ounce of madder, and one ounce of bran; then let the whole settle for half an hour. After all is settled and taken out of the boiler, and put into another copper with four ounces of indigo finely powdered, the liquor should be kept stirred, and very hot, but not be boiled. At intervals some lixivium of lime should be put into it, and that being cold will keep the liquor from boiling, and render the pot-ash more active.

As soon as the indigo is dissolved and properly diluted, damp the fire and cover over the solution; after it is settled put in a pattern, which, when taken out, will turn blue on being exposed to the air; if it does not, more clear lixivium must be added. Of this solution of indigo such proportions are to be added to the woad vat as are directed in the preceding process.

Rules to judge of the state of the woad vat.

The vat is ready for working, and to dye blue, when the sediment at the bottom, on being taken out of the vat changes to a fine brown-green. When the froth which rises in great bubbles on the surface is of a fine Prussian-blue, and when the pattern which has been steeped an hour, comes out of a dark grass-green, and changes in the air to a blue; when the liquor is clear and reddish, and the drops which stick to the rake are brown; when the sediment changes colour on being taken out of the liquor, and becomes brown on exposure to the open air: when the liquor is neither harsh nor greasy to the feel, and neither smells of lime nor of ley, the vat is known to be in a proper state for working.

Indications when a vat has had too much or too little lime.

These extremes ought to be carefully avoided. When the lime is deficient, or a pattern comes out of a dirty grey, and the sediment does not change its colour, there is scarcely any effervescence on the vat; the liquor smells only of lime, or of the lixivium of lime.

To remedy the deficiency of lime.

If the vat be not too far gone, after the addition of a little bran, madder, and some woad, then try the patterns from hour to hour; thus you will be enabled to judge.

A deficiency of lime is evident when there is no effervescence on the liquor; and when, by dashing about the surface of the liquor, it makes a hissing noise, and by the bursting of a number of small air bubbles, which as soon as they are formed break, and appear tarnished, and are not large, nor of a fine colour; the liquor too has an offensive smell, like rotten eggs; it is harsh and dry to the feel, and the sediment, as has been before observed, does not change colour when taken out of the liquor.

Sometimes such a condition of the vat is absolutely irremediable; but when not gone too far, sprinkle some lime into the liquor, and stir it. If you can thus remedy the defect, and bring the liquor to smell of lime, and to feel soft, cover the vat, and let it stand. If, at the expiration of an hour and a half, the effervescence begin, you may put in a pattern; in an hour afterwards, it may be taken out, and regulate your process by the degree of green which the pattern has imbibed; but, in general, when vats are thus out of order, they are not so soon recovered.

To work a vat which is in proper order.

The vat being in a proper state, the cross suspended, and thirty ells of cloth ready, or scoured wool in proportion, designed for black, by dyeing it of a blue grey; and having passed and repassed the cloth through the liquor for a full half-hour, it is to be wound round the winch, and thrown off into the barrow, and aired by the listings to change the green to blue. After this, a second piece may be dyed by the same process.

Having made this overture, or first stirring, as it is also called, the vat must be stirred afresh, adding lime; but not so much as to destroy the proper smell and feel. If the vat be in a good state, on the first day, it may be stirred three or four times; but it must not be overworked, particularly on the second day.

Concerning the colours to be obtained to the best possible advantage from a fresh vat on the first day,—the first is for black, the next for royal blue, and the third a brown green. On the second day, violet, purple, and Turkey blues in the last stirring. On the third day, if the liquor be too much diminished, it must be filled up with hot water. At the end of the week light blues may be done, and on Saturday night add rather more lime, to preserve the vat till Monday morning. On Monday morning add more indigo, and stir the paste; keep the vat liquor at a proper distance from the top. Cover it for two hours; then put in a pattern, and in an hour take it out; add lime according to the green shade of the pattern, and in an hour or two, if your vat has not suffered, you may begin working it afresh.

To keep the cloth, &c. from the sediment, there is always let down into the vat, before the work is begun, an iron circle, with cords fastened from the circumference to the centre.

Whatever be the cause, most certain it is, that the woad vat, even when prepared in the most careful and scientific manner, is soon disposed, if not used, to go into the putrid fermentation; of this we may be satisfied, when it smells like rotten eggs, as stated above.

The loss of a woad vat to dyers is extremely serious, both from the quantity of woad, as well as of indigo, which it contains: these articles being always expensive. The woad vat being worked by heat directly applied from an open fire, (the old method of heating it,) was much more liable to be lost than if it remained cold, or was worked continually, as it usually now is in London; added to which, the more equable application of heat by steam, there is not now the danger which there was in cessation, at uncertain times, and in uncertain states of the vat, as to richness or poorness of woad or of indigo. But a dyer in the country, whose business is barely sufficient to keep a vat going, will find more difficulty in this respect. If, therefore, he does a small batch of work on Monday, but has not half worked down his vat, and has no prospect for two or three days of doing any more work, he may possibly try to keep it with lime for a day or two: he may do so, and in the issue, in some instances, too much lime is the consequence. We consider, however, that when the vat can be worked daily, and replenished as it is worked down, as is the case in London, with care and attention, there is no danger of the loss of a woad vat: in London, such an accident now seldom happens. The author is, notwithstanding, persuaded that all the art of man cannot always keep a vat from the state of having either too much or too little lime, when heated but seldom, under a short course of work: for when a vat is in order, it is like a ripe vegetable; you must gather it, or it passes the time of its perfection; it may even be rotten ripe. We say, therefore, WORK THE VAT: withdraw from it, upon your cloth, its colour, which, as soon as you expose it to the atmosphere, will combine with its oxygen,—the oxygen with the carbon of the indigo and the woad. If you play with it too long, the putrid fermentation will begin, and the vat will be spoiled. The smell of rotten eggs always proclaims the approach of the mischief.

No one, therefore, should attempt to have a woad vat or vats, unless he can keep them nearly always at work. When worked down in a moderate time, and replenished with lime, woad, indigo, &c., working out and replenishing in, there can be no danger. On the other hand, in proportion as the vat is out of condition, although partially recovered, it must always be with more or less loss.

Methods of dyeing BLUES.

Whether the goods be cloth, or skeins of yarn, they must, in all cases, be first wetted out and wrung, and then put into the vat, worked in it, taken out and aired, that they may turn from green to blue; and, if necessary, they must be put in again.

There is no difficulty in dyeing dark blues, by repeated dippings; but if light blues be dyed in vats which are nearly exhausted, they will not be bright.

Blue vats, upon a large scale, are now mostly heated by steam; they are then, with little trouble, always in a state for working, without the necessity of re-heating. They are very convenient for light colours, even after they become very weak. In some instances, in order to dye light colours to the best advantage, it would be advisable to set a vat on purpose, which should be strong in woad and weak in indigo; because the colour would be given more slowly, and the light colour obtained from them with much more facility.

To dye wool with lac-dye, SCARLET and CRIMSON.

We have mentioned lac-lake and lac-dye in page 12. Lac-lake is of very uncertain quality, having many heterogeneous substances mixed with it. Lac-dye is very superior to lac-lake. Lac-dye is much used for dyeing woollen yarn scarlet and crimson, for carpets and hearthrugs. It is used with a peculiar spirit, which may be purchased of the dry-salters. Some think that this colouring material is nearly equal to cochineal; the author has, however, never seen any thing dyed with it equal to the colour obtained from cochineal, although it affords, nevertheless, a good scarlet.

Lac-dye is used by being powdered and put into a stone pan, (the quantity must be in proportion to what is likely to be used), with a portion of the above-named lac-spirit sufficient to make it about as fluid as treacle; it must be stirred with a glass-rod or a tobacco-pipe. Some use alum and tartar as a preparation, and some not. After putting the mixture of lac-lake and spirit in the copper with a proper quantity of water, add the goods and work them at a boiling heat. For scarlet add quercitron bark, for crimson, archil.

Lac-dye may be, however, prepared for dyeing, by submitting it, in powder, in a leaden vessel, to the action of sulphuric acid, in the proportion of not more than one part to two of the dye; and after the lac-dye is dissolved, the acid may be neutralized by carbonate of soda. With suitable mordants to the cloth or yarn, the colour may be then applied. Other processes for the employment of this dye are also adopted, but we have no room to detail them. (See Ure's Notes on Berthollet.)

To dye worsted yarn a CRIMSON.

Proportion of wool, one pound; of alum, two ounces and a half; of white tartar in powder, one ounce and a half. Having the water properly cleared by bran, let the alum and tartar be boiled in it; when it begins to boil, stir the mixture well, and put in the worsted, which boil in the liquor for two hours; then prepare a fresh liquor for the cochineal, one ounce of which, in powder, is to be used for every pound of wool; when it begins to boil, stir it well, put in the worsted, and boil it till the liquor in the vessel is free from colour, it having parted with the colouring matter of the cochineal, which should now all be upon the worsted. If a series of shades be required, less quantities of cochineal, alum, and tartar, must be used; the lightest shade is dyed first.

The preparation of archil to finish the CRIMSON.

Put as much archil as the goods may require, and according to the deepness or lightness of the shades of the crimson required, into a copper of water of a suitable size, and boil it, (the best canary archil will bear boiling); damp the fire, let the archil settle, and then have a fresh liquor for the goods to be put in, to receive a proportion of archil according to the pattern desired to be matched. Begin with the lightest and end with the deepest, reserving the remains of the archil liquor, if it be not all spent, for common compound colours of such shades as it will be advantageous to use it in. (See the next article.)

On dyeing wool SCARLET.

Scarlet owes its beauty to a solution of tin in muriatic acid. For this purpose some use muriate of ammonia, commonly called sal-ammoniac, others use common salt. It is of little consequence whether common salt or sal-ammoniac be used: different preparations are employed by different persons. The author has found the following to answer every expectation.

Melt an ounce of grain tin in an iron ladle, till an oxide is formed on the surface; then pour it from a height or distance into cold water. Pour the water from it, and it is fit for use, being then called feathered tin. Put this tin into a glass vessel or stone jar, and add to it eight ounces of nitric acid, eight ounces of water, half an ounce of sal-ammoniac, and two drachms of nitrate of potash. This preparation is better if made some time before it is used; it is a compound of nitrate and muriate of tin.

Should any one prefer a pure muriate of tin, the method of making it will be found in the last chapter, in observations on crimson and scarlet upon silk.

Into a copper of cleared boiling water, the heat being reduced, and having the worsted wetted out ready; for every pound of which (dry) put two ounces of cream of tartar or white tartar in powder, and one drachm and a half of cochineal in powder. When the liquor is ready to boil, add two ounces and a half of the first-mentioned solution of tin, which immediately changes the colour; stir it well: as soon as the liquor boils put in the worsted, and boil it till the colour of the cochineal is taken up by it. The worsted must now be taken out, when it will be of a flesh-colour, the water in the copper having lost its colouring matter. To finish the worsted, another quantity of clean water is made warm, into which six drachms and a half of cochineal are to be put; just before it boils, two ounces of the same solution of tin are to be poured in, the liquor undergoing a similar change as before. The worsted is again put in, and boiled till it has imbibed the colour; it is then taken out, wrung, and rinsed in clean water, when the scarlet is in perfection.

One ounce of cochineal to a pound of wool, will impart a colour sufficiently deep, if managed according to the method above described, no colour being left in the remaining liquor.

For many shades of scarlet it will be, however, necessary, and, in a fresh liquor, to add either a certain portion of turmeric or young fustic, to give the scarlet that fiery red which some scarlets have. If not in an entire fresh liquor, a part of the old liquor must be taken out before the yellow is added.

When it is wished to dye a regular series of scarlet shades in worsted, half the quantity or less, for some of the lightest, will be sufficient of the solution of tin, the tartar, the cochineal, &c. The worsted should be separated into divisions corresponding with the shades required; the lightest is of course to be done first: if any deficiency be in the shade, it may have another dip. This deficiency is easily perceived, and a very little practice will enable the operator to assort them perfectly.

It should be noted, that the vessel most proper to dye scarlet in ought to be made of block tin; such as are used by the scarlet dyers for the East India Company.

When woollen cloth is to be dyed scarlet, to every hundred pounds of cloth put six pounds of tartar and eighteen pounds of the solution of tin at first; the same quantity in the completion; and in each operation, six pounds and a quarter of cochineal. For the accommodation of those who would make small experiments, one ounce of cream of tartar, six ounces of solution of tin, and one ounce of cochineal, may be used for every pound of worsted or cloth, putting two-thirds of the solution of tin and the tartar, and a quarter of the cochineal, into the preparation, and the remainder to the completion.

Observe, that although we have given processes for dyeing woollen cloth crimson as well as scarlet, yet crimson may be obtained in another way: for alum, the salts in general with an earthy base, and the fixed and volatile alkalies, possess the property of changing the colour of scarlet into crimson, the natural colour of the cochineal. The cloth which is dyed scarlet has only to be boiled, therefore, for about an hour, in a solution, more or less charged with alum, according as a deeper or lighter crimson is wanted. When a piece of scarlet has any defects, it is set apart for crimson. Soap and potash will also produce crimson from scarlet, but not of so bright a colour as from alum. Hence also we learn the necessity, in, at any time, working scarlet cloth, to avoid boiling it with soap or pot-ash, &c. if we desire the scarlet to remain.

To dye wool MAROON.

The worsted or yarn must be boiled for an hour or two in one twelfth its weight of alum and the same quantity of white argol. It is best, when there is a large quantity of yarn, to do this on the preceding day: if your copper hold a pack of two hundred and forty pounds, it will be cold enough to handle after remaining with the fire out during the night.

When the skeins, &c. are taken out and arranged upon poles or sticks, have a fresh water ready in the copper, into which put about thirty pounds of chipped peach-wood, and when it has boiled half an hour, pour in some water to cool it down, and add fifteen pounds of crop madder; work the yarn in this liquor rather under a boiling heat. When it is full enough, for some shades you must add archil. As the whole pack is dyed at four or five turnings in, some of the parcels may be varied in the hues instead of confining them all to one shade. The various turnings will take the greater part of the day to perform. When you choose to have as many shades as there are turnings in, you divide the drugs into different portions for different periods of the time, to be used according to the patterns required. The most economical method of using the drugs being to follow the patterns one after the other: practice will teach the operator to do this most advantageously.

More madder than peach-wood gives a lively red; more peach-wood than madder gives a bright maroon red, bordering on crimson, but more so without any madder; with the addition of archil it gives a crimson, but by no means to be compared with the crimson of cochineal. Urine with the archil renders a less quantity of archil necessary.

To dye wool YELLOW.

The proportion of alum used by dyers in these processes varies from one-fourth down to one-twelfth, of tartar one-sixteenth is used, for every pound of cloth. Equal parts of alum and tartar are used for worsted and yarn, each of which (alum and tartar) is only from one-twelfth to one-tenth of the weight of the material to be dyed.

The shades of yellow are straw yellow, pale yellow, lemon yellow, and full yellow.

In order that the cloth should be properly impregnated with the mordants of alum and tartar, according to what is allotted to the shade, whether light or full, it should be boiled in the preparation at least one hour; two hours for a full yellow; then a fresh liquor is to be made to receive the weld, which must be previously boiled: for a full yellow four or five pounds of weld will be required to one pound of cloth or worsted; for the lighter shades less of course: but a sufficient quantity only of weld should be used, and this should be boiled and re-boiled, as it will keep but a very little time after boiling. If you have a gradation of shades you will save drugs and expense by dyeing the fullest shades first, and the lightest last; but by this method the lightest will not be so bright as if they were done first, and the liquor renewed with fresh boiled weld, and so on to the fullest shade. At last you must have for the goods a preparation weak or strong according to the light or full colour of which they are to be. The last dyeing, whether of cloth or yarn, will assuredly take all the colour out of the liquor of any consequence.

While expense is not an object, it is best, not only for yellows, but for all other colours, to have the preparation and the dye proportioned to the shade, the colour done at once, and the remaining liquor thrown away; but as the price usually paid for dyeing will not enable the dyer so to do, he commonly dyes his shades in succession, as above, and with the utmost economy.

To dye wool BROWN, or of a FAWN COLOUR.

These shades are extremely various, and are dyed without any preparation with alder-bark, red sanders, sumach, galls, madder, &c. and under a boiling heat, although it is occasionally necessary to boil some of the ingredients together previous to the dyeing: for instance, red sanders will give its colour out best when boiled with galls, alder-bark, sumach, &c. Cam-wood, bar-wood, walnut rinds, roots, &c. are used in some of these shades, the varieties of which are almost infinite. Practice is required in this branch of dyeing equal to or beyond any other.

To dye wool PURPLE, &c.

Pass the goods through archil, next through the blue vat, with the usual precautions, then through hot water. For some shades they should be alumed, and then dyed with cochineal for the crimson part of the purple. Blue and crimson make purple, violet, &c. according to the patterns required.

To dye wool GREEN.

The shades of this colour are very numerous, as yellow green, pale green, bright green, grass green, laurel green, olive green, sea green, parrot green, cabbage green, duck's-wing green, &c.

The goods must first have a blue ground from the woad vat, light or full according to the pattern, they are afterwards to be prepared with alum and tartar, weak or strong according to the lightness or fulness of the pattern, and are afterwards dyed in weld liquor. Many of the shades of green are more readily done by dyeing the wool first yellow with old fustic, with a preparation of alum and tartar, and using the chemic blue vat made with sulphuric acid and indigo. See page 47.

A chemic vat for GREEN WOOLLEN.

Prepare in the manner described for cotton (page 52.), eight ounces of indigo and four pounds of sulphuric acid. This preparation need not, however, be neutralized for wool as described for cotton. In some instances the preparation is to be for the yellow of fustic one-twelfth of alum, the same quantity of tartar, and in some cases one-twelfth of alum only.

A chemic vat for BLUE WOOLLEN.

This is to be made the same as for green; it need not be neutralized as for cotton. For blue, however, twelve ounces of indigo are necessary to four pounds of sulphuric acid. In dyeing the heat must be much under boiling, or the using of a high heat would give the blue a green tinge. This blue colour is very bright, yet not fast, but no preparation is of any advantage to either its fastness or brightness. Some put alum and tartar, and some use one, and some the other, to prevent a green cast: if, however, the wool be fine, white, and worked much below the boiling point of heat, it will not turn green although neither be used.

To dye wool ORANGE, GOLD COLOUR, &c.

The processes of crimson, scarlet, and of yellow united produce the various shades of these colours, leaving archil out. See buff, peach, &c. on wool.

To dye wool BLACK.

Black includes a prodigious number of shades, beginning from the lightest grey or pearl colour to the most intense shade of black. On account of these shades it is classed by dyers among their chief or primitive colours[8]; for the greater number of browns, of whatsoever shade they be, are finished in the same dye as would dye white wool a grey more or less dark. This operation is called browning. The best superfine black should have a full ground of mazarine blue previously to being finished black. A great quantity of cloth and other articles have, however, no indigo ground, but a ground of logwood, or of logwood and alder-bark, or of logwood and old fustic, or of logwood, alder-bark, and old fustic, all boiled together, and sometimes they are boiled in a decoction of oak saw-dust.

Indigo for the ground is the richest drug, in carbon, that is or can be used; logwood is next to it: too much logwood, however, whether indigo be used with it or not, gives the black a foxy hue; alder-bark and old fustic modify this effect, and are used in small quantities for this purpose, because the dye from these, as well as that from oak saw-dust, will produce a soot or dead black.

A jet black is required full and rich, therefore old fustic and oak saw-dust are only used to modify the richness of the ground as it regards the blue, whether of indigo or of logwood; for logwood especially, without these, if overcome with sumach and sulphate of iron only, would be foxy, purplish, or have a reddish cast.

So many different grounds being used for blacks, and every dyer thinking his own the best, is the occasion of such a great variety of hues, even of black, being found in the market. It is, therefore, thought unnecessary to describe the various methods of dyeing black which are pursued by different dyers, and which would be, in fact, impossible. But the author has done what is of much greater importance to the student, who, after a little practice, let him have a pattern of black to dye, will know how to do it, let who may have dyed it.

Even a blue-ground is, according to some, dyed afterwards in a decoction of logwood and galls, or logwood and sumach, and two pounds of verdigris for a hundred pounds of cloth. Thus, ten pounds of logwood and ten of galls, are to form the decoction, and are boiled previously for twelve hours. One third of it with the verdigris is used first, and then the cloth, after boiling in it for two hours, is aired; it is then passed through one third more of the decoction of logwood and galls, having previously had eight pounds of sulphate of iron dissolved in it, and the scum arising from the solution taken off. The goods are to be worked in this one hour at a boiling heat, then aired again by turning them about on a stone floor. The remainder of the decoction of logwood and galls is then added, with fifteen or twenty pounds of sumach; boil it some time, and then add five pounds of sulphate of iron; scum it, and let the liquor cool down, then put the goods in, and work them at a boiling heat an hour or two, taking them out once or twice, at least, in the time, to air and cool; they are then to be well washed, and passed through a decoction of weld liquor, to soften the black, which will be very fine. This process is chiefly from Hellot; but the quantity of sulphate of iron is more by three pounds than he directs.

When the cloth is blue, it is usually boiled two hours in a decoction of galls, then washed and aired, when sulphate of iron and logwood are added to the liquor, and the goods worked in it for two hours, and then washed.

The above have been the processes in practice for a century past in France, where the galls were not so dear as they now are in England: sumach is here, therefore, now most commonly used as a substitute for galls.

Another process for BLACK without a blue ground.

To dye one hundred weight of cloth, take thirty pounds of chipped logwood, half a bushel of alder-bark, and six pounds of sumach, and boil them together in a proper quantity of water for half an hour; then cool the decoction down with cold water, enter the cloth, turning it on the winch; bring it to a boil, having the sumach in a bag; boil and keep the cloth turning for one hour and a half: this is the ground. Have now ready fourteen pounds of sulphate of iron dissolved in water, which is to be laded into the copper by one man, while another turns the cloth for an hour at a boiling heat; it is then to be taken out, cooled, and aired, returned to the copper, and boiled gently for two hours, and then cooled again.

While the cloth is cooling, six pounds of logwood, ten pounds of alder-bark, two pounds of argol, ten of soda, or common pot-ashes, and three pounds of sulphate of iron, are to be added to the liquor in the copper, and boiled one hour, when the goods must be turned and worked one hour; and, lastly, taken out and aired. This black is said to be of the hue of a raven's feather. This process is from Heigh.

The argol is professed to be put in to counteract the sulphuric acid of the sulphate of iron; the alkali is said to cause the logwood to retain its natural violet colour: and if too great a quantity of logwood be not used, the result would be as above stated. But the author presumes that such a black would not be at this time much esteemed. We object to the introduction of so much, indeed of any alkali or argol, as the time employed in performing the process is wasted. Alkali is good, however, where a chemic green is to be dyed black.

Wool will take up whatever the copper contains necessary to dye black; but, for the beauty of the colour and the durability of the cloth, it is best to let it have most of its ground of vegetable colour before it has the sulphate of iron, which blackens that ground, with sumach instead of galls; and even in some instances, dyeing some goods without the sumach.

Were the author, however, to direct the dyeing of black cloth, such as should be of the best kind, he would have an indigo ground with logwood and alder-bark, without old fustic or oak saw-dust; and to finish the cloth he would use sumach, sulphate of iron, and a small quantity of verdigris. He would give it the blue ground first; then the logwood, alder-bark, and verdigris; and then finish it with sumach and sulphate of iron.

If the blue ground were omitted, he should dye the cloth twice, giving it more of logwood and alder-bark, but verdigris the same; and finish it with sumach and sulphate of iron. Nevertheless, when we dye to a pattern, the pattern must be our guide.

Different goods will require different quantities of drugs. Logwood should be about one-fourth of the weight of the goods; the sulphate of iron about one-fifth of the logwood; alder-bark, when used, about the same quantity as sulphate of iron; but for some yarns this bark is not used, nor is it necessary; and where fustic or oak saw-dust is used, there is the less necessity for using alder-bark. The sumach must be about the same quantity as sulphate of iron. Remember that carbon is generally considered as that which makes the richness of a dye. That it is the iron in the sulphate of iron, combined with the tannin and gallic acid which are assumed to be in the sumach and logwood, that produces the blackness of the dye; but this theory is questionable. See below.

The way to ascertain when the quantities of drugs are most appropriate for producing the desired effect is as follows:—

First, ground with different quantities of drugs, from three to five or seven patterns, and use from one third to one fifth of sulphate of iron and sumach to the grounding; afterwards finish with the remainder of the sulphate of iron and sumach: the fuller the ground the richer will be the black, if the logwood be not in excess, and the quantities be used as thus stated.

We ought also to state here (from Berthollet, vol. ii. p. 4.) that commonly more simple processes than any of those above described are employed for black. Thus the blue cloth is simply turned through a bath of gallnuts, when it is boiled for two hours. It is next passed through a bath of logwood and sulphate of iron for two hours without boiling, after which it is washed and fulled.

A black may also be dyed without a blue ground with walnut rinds or the roots of the walnut tree; in this case the cloth receives a dun ground from the walnut husks or roots, and is afterwards made black in the manner above described, with logwood and sulphate of iron. The blacks, however, without the blue ground are only given in general to inferior cloths.

The colouring principle of logwood is called hematin; it is crystalline, of a rosy-white, and, viewed through a lens, very brilliant; its taste is slightly astringent, bitter and acrid; exposed to the action of fire in a retort it affords all the products of animal substances, and also a small quantity of ammonia, which proves that it contains nitrogen. It dissolves easily in boiling water; on adding some acid very gradually, it changes to yellow and then red. Potash and ammonia give the solution of hematin a purple red; if a great excess of these alkalies be added, the colour becomes violet-blue, then brown-red, and finally yellow-brown. In this state it is decomposed and cannot be recovered by any acids. Protoxide of lead, protoxide of tin, hydrate of tritoxide of iron, hydrate of copper, oxide of zinc and its hydrate, flowers of antimony and oxide of bismuth combine with hematin and give it a blue colour, with the loss of the violet shade. See notes to Ure's Berthollet, vol. ii. p. 420. See the explanation of protoxide, &c. under OXIDE in Chapter I.

The above facts concerning logwood may, by the ingenious dyer, be applied on many occasions with great success.

To dye wool GREY.

All greys, from the darkest to the lightest, are composed of black in varying proportions. They are of great use in dyeing, not only for their own colours, but also when applied to other colours, which operation is called saddening or darkening.

Some greys have a woad ground of blue, then of logwood, sumach or sulphate of iron, of which decoctions of the three last, for expedition, should be in readiness when wanted. When a succession of light shades, in particular, is required, in some instances the chemic blue is used: when we treat of the mixture of black, or rather grey with red and blue, the utility of grey will be seen.

Mixture of BLACK or GREY with RED and BLUE.

These produce an infinite number of all shades of grey as sage grey, slate and lead colour, and others still darker.

On BROWNS, FAWNS, OLIVES, &c.

Browns and Fawns owe, in all probability, their colour to the iron which their dyes contain. Iron is so universally diffused throughout nature, that it, very likely, enters into the composition of many other colours; it exists in blood, in water, and in innumerable vegetable and animal substances, as well as in earths and many minerals. Hence we ought not to be surprised that blue, red, and fawn produce olives from the darkest to the lightest; as well as slate and lavender when the shade is very light.

Fawn and yellow produce the feuille-morte or dead-leaf.

Fawn and red produce cinnamon, tobacco, chestnut, &c. Fawn and black produce coffee, maroon, &c.

Blue, yellow, and black produce all the dark greens, even to black.

Blue, fawn, and black produce dark olives and greenish greys. Red, yellow, and fawn produce orange, gold colour, withered-leaf, carnation, burnt cinnamon and tobacco colours of all kinds.

Yellows, fawn, and black produce hair colour, nut-brown, &c.

This enumeration is meant only to give a general idea of the ingredients proper for the production of shades composed of several colours.

Where red forms a component part of the colour wanted, the goods must have a preparation of alum and argol, strong or weak, according to the fulness or weakness of the red which forms a part of the compound dye, such as the half or quarter of the quantity which is required for a full colour of red; the same as to yellow, and, in proportion, when red and yellow are joined.

On the YELLOW of the Quercitron or American bark.

The quercitron bark is said to yield from eight to ten times more colour than weld, and about four times more than old fustic; this was, however, Dr. Bancroft's account, who had a strong interest in this dyeing drug, as stated in the first chapter. He also asserts, that one pound of bark with muriate of tin, will dye forty pounds of woollen a bright golden yellow, which afterwards becomes a beautiful and durable scarlet, with a fourth part less cochineal than is usually employed on other occasions for such a colour. But Bancroft did not succeed in doing away the old method of saving tartar and cochineal.

His fullest yellow upon cloth, the author has, however, often tried and found it rich and golden; the process is as follows:

Cloth one hundred pounds; bark in powder, and in a bag, ten pounds; muriate of tin, or murio-sulphate of tin, (for which see forward,) ten pounds. The bark in the bag must be first immersed in the proper sized vessel for six or eight minutes; then add the solution of tin and stir it well for two or three minutes, when the cloth must be put in, and kept in motion by two or three men working over the winch from end to end; then proceed to boil; and, in fifteen minutes boiling, the highest yellow is produced; a longer time would turn the yellow brown.

When a very bright yellow, approaching less to orange, is wanted, seven or eight pounds of solution of tin, five pounds of alum, and ten pounds of bark, will do for a hundred pounds of cloth. In this process, boil the bark first in a bag for a few minutes, then add the solution of tin and the alum, and the cloth afterwards, as before directed; less body requires less quantities of course.

For a full BRIGHT YELLOW delicately inclining to a greenish tinge.

Use eight pounds of quercitron bark, to six of muriate of tin, six pounds of alum, and four pounds of white tartar, for cloth as before. The alum and tartar render the yellow more delicate, and give it more of the lemon or greenish tinge; where this is wanted in the greatest perfection proceed as follows: Take ten pounds of bark, ten of muriate of tin, or murio-sulphate of tin, ten of alum, and ten of tartar. For cloth three or four times the quantity of the preceding processes may be taken, namely three or four hundred pounds.

In this process the bark must be boiled fifteen minutes in water only, and then the other ingredients be added and mixed in the liquor by stirring. The cloth is next to be put into it, the liquor being first cooled a little; it is then immediately to be turned briskly on the winch till the colour is sufficiently raised.

When a variety of shades are wanted, in working the bark, (contrary to the processes for many other colours) the higher shades should, in this colour, be dyed first, and the weaker afterwards. When about two-thirds of the quantity of the cloth have been dyed, it will be generally found that the liquor, by continuing to extract colouring matter from the bark, has acquired an over proportion, and wants a small quantity of muriate of tin, of alum, and of tartar, perhaps a pound of each, to enable the bark at last, as well as at first, to give the same delicate, pale and greenish tinge. A surer way, however, is to boil the bark in a small quantity of water, separately, for six or eight minutes; and then to add to it the solution of tin, alum, and tartar, and boil them with the bark together for fifteen minutes, and then damp the fire; then have the cloth in a proper sized vessel, supplied with boiling water, and the cloth moving on the winch; after it has gone a few turns round, and is thoroughly wetted out (which it should be before, and now again) lest any part should be dry, add the supplies of the yellow liquor above described, by little and little as they may be wanted: in this way expectation is surpassed by the beauty produced.

Bancroft's murio-sulphate of tin

is made thus:—Take of muriatic acid, three pounds; of feathered tin, as described in the process of dyeing wool scarlet, fourteen ounces; to the tin add gradually the muriatic acid; afterwards, with due and great precaution, by degrees, in the course of a day or two, two pounds of sulphuric acid. Care must be taken that the vessel in which this operation is conducted, be of stone ware or of glass. These acids being mixed with the tin, should be left to saturate themselves with it, which they will do in time, without artificial heat; but the dissolution of the tin will be rapidly promoted by a sand heat. This murio-sulphuric solution of tin, thus made, will be perfectly transparent and colourless, and will probably remain so for years, without suffering any precipitation of the metal.

To dye wool BUFF.

This is done with the most economy after scarlet, and, in such case, requiring very little addition (in some cases none) of cochineal. The wool, having an alum preparation, it may be requisite to add some fresh prepared decoction of young fustic or weld. See the next article.

To dye wool PEACH.

This process is the same as the last; that is, after scarlet; but the wool is not to be alumed: in some cases, a little tartar and cochineal is added. Observe, that the cochineal and tartar being added, the previous preparation must be according to the fulness or faintness of the shade wanted, whether of buff, peach, or flesh, all of which require, essentially, the same process. By such means, a pattern of any shade, compounded of red and yellow, from scarlet to the weakest buff and flesh, may be produced.

To set an indigo vat for worsted, serge, &c.

The vat being five feet high, and two feet in diameter at top, you may use for it from two to six pounds of indigo, according as you set it light or full.

Boil two pounds of potash, two ounces of madder, and a handful of bran, in fifteen gallons of clear soft water, for half an hour.

The indigo must be powdered; after which it must be levigated in a peculiar circular cast-iron mill, having a contrivance for two large round stones, or cast iron balls, which are kept in a perpetual circular motion while the indigo is ground. Water it, and put it into the mill, and as the balls run round, the indigo in the water is reduced to a fine flowery paste. There are mills more convenient than these, but, perhaps, none more simple for a small concern.

When the indigo is thus prepared, boil it in the copper with the grounds of the madder and the potash, which fell to the bottom; it is all, then, to be put into the vat at the same time with the indigo; the whole is to be stirred, the vat covered, and heat applied to make it more than blood warm, and to keep it so. The vat should be stirred twice, slightly, both the second and third day, the heat remaining the same; when a brassy scum, divided and interrupted in many places, begins to appear on the surface. On the fourth day, the heat being continued, the scum becomes more perfect and less broken, the froth which rises, upon stirring, is more blue, and the vat a deep green.

When it becomes green in this manner, it is an indication that it must be filled; to do which, boil half an ounce of madder, and one pound of potash, in five gallons of water; put in this liquor, and stir it; if it produce much froth, stir it again, and the next day it will be fit for working; which, however, will be sufficiently known by the quantity of froth, and by the brassy and scaly crust on the surface of the liquor, on blowing or stirring which, the liquor beneath is green, although the surface appears brown or blue.

When the vat has worked about forty or fifty pounds of serge or worsted, it may be necessary to replenish it with one pound of potash, half an ounce of madder, and a handful of bran; these being boiled a quarter of an hour, are added to the vat.

When this vat wants replenishing with indigo, which may be known by the liquor being no longer green, but brown, blue, or almost black, two-thirds of it must be put into a copper; when ready to boil, the scum on the top must be taken off by a sieve, after which it should be suffered to boil, with the addition of two handfuls of bran, a quarter of a pound of madder, and two pounds of potash; soon after it has boiled, it is to be put into the vat with one pound of indigo, prepared as before; the vat being again stirred, and covered, the heat always remaining between blood and fever heat.

When an indigo vat has been several times re-heated, it should be emptied out entirely, and set anew, because the colour becomes dull. The preceding process is from Hellot.

[8] It is necessary that the student should not confound the terms primitive colours here with the prismatic or primary colours, for the discovery of which we are indebted to Sir Isaac Newton. See the Introductory Chapter.

Clyx.com