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.
_On the putrefaction of the woad vat._
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_.