574 
DYEING. 
lead, and three parts of alum, in a sufficient 
quantity of water. This solution should be 
heated to the temperature of 100° : the cloth 
should be soaked in it for two hours, then 
wrung out and dried. The soaking may be 
repeated, and the cloth again dried as before. 
It is then to be barely wetted with lime-water, 
and afterwards dried. The soaking in the 
acetite of alumina may be again repeated ; 
and if the shade of yellow is required to be 
very bright and durable, the alternate wetting 
with lime-water and soaking in the mordant 
may be repeated three -or four times. By 
this contrivance, a sufficient quantity of 
alumina is combined with the cloth, and the 
combination is rendered more permanent by 
the addition of some lime. The dyeing-bath 
is prepared by putting 12 or 18 parts of quer- 
citron bark (according to the depth of the 
shade required), tied up in a bag, into a suf- 
ficient quantity of cold water. Into this bath 
the cloth is to be put, and turned round in it 
for an hour, while its temperature is gradu- 
ally raised to about 120°. It is then to be 
brought to a boiling heat, and the cloth al- 
lowed to remain in it after that only a few 
minutes. If it is kept long at a boiling heat, 
the yellow acquires a shade of brown. 
Of dyeing red . — The colouring matters 
employed for dyeing red, are kermes, cochi- 
jieal, archil, madder, carthamus, and Brazil- 
wood. 
Kermes is a species of insect, affording 
a red colour by solution in water ; but it is 
not so beautiful as cochineal, which is like- 
wise an insect brought from America (see 
both under Coccus). The decoction of co- 
chineal is a very beautiful crimson-colour. 
Alum brightens the colour of the decoction, 
and occasions a crimson precipitate. Muri- 
ate of tin gives a copious fine red precipitate. 
Archil is a paste formed of a species of 
lichen pounded, and kept moist for some time 
with stale urine. 
Madder is the root of a well-known plant, 
rubia tinctorum. 
Carthamus is the flower of a plant (car- 
thamus tinctorius), cultivated in Spain and 
the Levant. It contains two colouring mat- 
ters-: a yellow, which is soluble in water; and 
a red, insoluble in water, but soluble in alka- 
line carbonates. The red colouring matter 
of carthamus, extracted by carbonate of 
soda, and precipitated by lemon-juice, con- 
stitutes the rouge employed by ladies as a 
paint. It is afterwards ground with a certain 
quantity of talc. The fineness of the talc, 
and the proportion of it mixed with the car- 
thamus, occasion the difference between the 
cheaper and dearer kinds of rouge. 
Brazil-wood is the wood of a tree growing 
in America and the West Indies (See Cje- 
salpin ia). Its decoction is a fine red colour. 
None of the fed colouring matters has so 
strong an affinity for cloth as to produce a 
permanent red, without thfc assistance of mor- 
dants. The" mordants employed are alumina 
and oxide of tin ; oil, and tan, in certain pro- 
cesses, are also used ; and tartar, and muri- 
ate of soda, are frequently called in as aux- 
iliaries. 
Coarse woollen stuffs are dyed red with 
madder or archil ; but fine cloth is almost 
exclusively dyed with cochineal, though the 
colour which it receives from kermes is much 
•more durable. Brazil-wood is scarcely used, 
except as an auxiliary, because the colour 
which it imparts to wool is not permanent. 
Wool is dyed crimson, by first impreg- 
nating it with alumina, by means of an alum 
bath, and then boiling it in a decoction of 
cochineal, till it has acquired the wished-for 
colour. The crimson will be finer if the tin 
mordant is substituted for alum ; indeed, it 
is usual with dyers to add a little nitro-muri- 
ale of tin, when they want line crimsons. 
The addition of archil and potass to the co- 
chineal, both renders the crimson darker, 
and gives it more bloom ; but the bloom 
very soon vanishes. For paler crimsons, 
one-half of the cochineal is withdrawn, and 
madder substituted in its place. 
W ool may be dyed scarlet, the most splen- 
did of all colours, by first boiling it in a so- 
lution of murio-sulphate of tin, then dyeing 
it pale yellow with quercitron bark, and 
afterwards crimson with cochineal ; for scarlet 
is a compound colour consisting of crimson 
mixed with a little yellow. 
Silk is usually dyed red with cochineal or 
carthamus, and sometimes with Brazil-wood. 
Kermes does not answer for silk; madder is 
scarcely ever used for that purpose, because it 
does not yield a colour bright enough. Ar- 
chil is employed to give silk a bloom ; but it 
is scarcely used by itself, unless when the 
colour wanted is lilac. 
Silk may be dyed crimson by steeping it 
in ^a solution of alum, and then dyeing it in 
the usual way in a cochineal bath. 
'The colours known by the names of poppy, 
cherry, rose, and flesh-colour, are given to 
silk by means of carthamus. The process 
consists merely in keeping the silk as long 
as it extracts any colour, in an alkaline solu- 
tion of carthamus, into which as much lemon- 
jujee, as gives it a fine cherry colour lias 
been poured. 
Silk cannot be dyed a full scarlet ; but a co- 
lour approaching to scarlet may be given it, 
‘by first impregnating the stuff with murio- 
sulphate of tin, and afterwards dyeing it in a 
bath, composed of four parts of cochineal, 
and four parts of quercitron bark. To give 
the colour more body, both the mordant and 
the dye may be repeated. A colour ap- 
proaching scarlet may be also given to silk, 
bv first dyeing it in crimson, then dyeing it 
with carthamus, and lastly, yellow without 
heat. Cotton and linen are dyed red with 
madder. 'The process was borrowed from 
the East; hence (he cplour is often called 
Adrianople or Turkey red. The cloth is 
first impregnated with oil, then with galls, 
.and lastly with alum. It is then boiled for 
an hour in a decoction of madder, which is 
commonly mixed with a quantity of blood. 
After the, cloth is dyed, it is plunged into a 
soda ley, in order to brighten the colour. 
The red given by this process, is very per- 
manent, and when properly conducted, it is 
exceedingly beautiful. The whole difficulty 
consists in the application of the mordant, 
which is by far the most complicated em- 
ployed in the whole art of dyeing. 
Cotton may be dyed scarlet, by means of 
murio-sulphate of tin, cochineal, and querci- 
tron bark, used as for silk, but the colour is 
too fading to be of any value. 
Of dyeing black . — The substances employ- 
ed to give a black colour to cloth are, red 
oxide of iron, and tan. These two sub- 
stances have a strong affinity for each other ; 
and when combined, assume a deep black co- 
lour, not liable to be destroyed by the action 
of air or light 
Logwood is usually employed as an auxili- 
ary, because it communicates lustre, and 
adds considerably to the fullness of the 
black. It is the wood of a tree (.See II je m a- 
toxvlon) which is a native of several of the 
West India islands, and of that part of Mexico 
which surrounds the Bay of Honduras. It 
yields its colouring matter to water. The 
decoction is at first a fine red, bordering on 
violet ; but if left to itself, it gradually as- 
sumes a black colour. Acids give it a deep 
red colour ; alkalis a deep violet, inclining to 
brown; sulphate of iron renders it as black 
as ink, and occasions a precipitate of the same 
colour. 
Clpth, before it receives a black colour, is 
usually died blue: this renders the colour 
much fuller and finer than it would otherwise 
be. If the cloth is coarse, the blue dye may 
be too expensive; in that case, a brown co- 
lour is given, by means of walnut-peels. 
Wool is dyed black by the following pro- 
cess. It is boiled for two hours in a decoction 
of nut-galls, and afterwards kept for two hours 
more in a bath composed of logwood and sul- 
phate of iron, kept during the whole time at 
a scalding heat, but not boiled. During the 
operation, it must be frequently exposed to 
the air ; because the green oxide of iron, of 
which the sulphate is composed, must be con- 
verted into red oxide by absorbing oxygen, 
before the cloth can acquire a proper colour. 
The common proportions are five parts of 
galls, five of sulphate of iron, and thirty of log- 
wood, for every hundred of cloth. A little 
acetite of copper is commonly added to the 
sulphate of iron, because it is thought to im- 
prove the colour. 
Silk is dyed nearly in the same manner. It 
is capable of combining with a great deal of 
tan ; the quantity given is varied at the plea- 
sure of the artist, by allowing tiie silk to 
remain a longer or shorter time in the decoc- 
tion. 
It is by no means so easy to give a full black 
to linen and cotton. The doth, previously 
dyed blue, is steeped for 24 hours in a decoc- 
tion of nut-galls. A bath is prepared, con- 
taining an acetite ot iron, formed by satura- 
ing acetous acid with brown oxyd of iron : 
into this bath the cloth is put in small quan- 
tities at a time, wrought with the hand for a 
quarter of an hour, then wrung out, and aired 
again ; wrought in a fresh quantity of the bath, 
and afterwards aired. These alternate pro- 
cesses are repeated, till the colour wanted is 
given : a decoction of alder-bark is usually 
mixed with the liquor containing the nut- 
galls. 
Of dyeing broivn. — Brown, or fawn colour, 
though in facta compound, is usually ranked 
among the simple colours, because it is appli- 
ed to cloth by a single process. Various 
substances are used for brown dyes. 
Walnut-peels, or the green covering of 
the walnut, when first separated are white 
internally, but soon assume a brown, or even 
a black colour, on exposure to the sir. 
They readily yield their colouring matter to 
water. They are usually kept in large casks, 
covered with water, for above a year before 
they are used. To dye wool brown with them, 
nothing more is necessary, than to steep the 
cloth in a decoction of them till it has acquired 
the wished-for colour. The depth of the 
shade is proportional to the strength of the 
decoction. The root of the walnut-tree 
