168 D Y I 
penciled over blue figures or defigns, produces a green, 
and on white parts or grounds, a yellow colour; neither 
of which is fufficiently durable. 
The art of calico-printing, (ince its introduction to 
Europe, has been diverted of many tedious operations 
and manipulations, which would have proved infupport- 
ably expenfive here, on account of the higher price of 
labour, and of almoft every thing neceffary to human 
fubfirtence. But the greateft European improvement in 
this art refpefts the aluminous mordant, and depends 
on the employment of fugar or acetit of lead, or the 
oxyd of that metal diffolved by diftilled vinegar, and 
cryftallized ; which, within the memory of man, has been 
gradually brought into ufe, without any theory or even 
fufpicion of its true effect, or of the way in which it 
proved fo highly ufeful. This improved aluminous 
mordant is now generally made for calico-printing, by 
diffolving three pounds of alum in a gallon of hot water; 
then adding one pound, or in fome particular cafes one 
pound and a half, of the acetit or fugar of lead, (lining 
the mixture well during two or three days, and after¬ 
wards adding to it about two ounces of pot-alh, and as 
many of clean powdered chalk, called carbonat of lime. 
The mixture being thus made, and the clear liquor de¬ 
canted from the fediment, it is afterwards thickened with 
flour, if intended to be printed or applied by the block, 
and with the gum of the Mimofa Nilotica, gum Arabic ; 
or of the Mimofa Senegal, gum of Senegal, if it be intended 
for pencilling; and being applied in either of thefe ways 
to linens or cottons, it is afterwards very thoroughly 
dried in a room artificially heated, and then the pieces 
of linen or cotton, fo printed or penciled with the mor¬ 
dant in queftion, are cleanfed as perfectly as poflible, by 
foaking and working them in a ciftern with warm water 
and cow-dung, and afterwards rincing them in clean wa¬ 
ter to dilTolve the gum or flour, and feparate the fuper- 
fiuous or loofe parts of the mordant, which otherwife 
would in the dying veffel combine with the colouring 
matter, and greatly ftain the grounds, or parts intended 
to be prelerved white. This will indeed unavoidably 
happen in fome degree, notwithrta-nding the molt perfect 
cleanfing. But as the colouring matter which thefe 
grounds or parts abforb from the dying liquor will not, 
when the clo'ths have been thoroughly cleanfed, be re¬ 
tained or fixed by any bafis, they are fpeedily whitened, 
by being boiled in water with bran, and expofed upon 
the grafs with the wrong fide upward. 
When the practice of calico-printing was firft intro¬ 
duced into Europe, a confiderable number of ufelefs re¬ 
cipes for making the feveral mixtures employed as mor¬ 
dants were introduced with it. The calico-printers, 
without any fyftem or reafonable motive, appear in dif¬ 
ferent inftances to have ufed verdegris, arfenic, corroftve 
fublimate, blue vitriol, litharge, and white lead. Find¬ 
ing at length that only ffie two laft were of any ufe, it 
happened that fome dyers began to omit one, and fome 
another, of thefe ingredients, until at'length all the ufe¬ 
lefs ones were laid afide, though without the aid of any 
chemical knowledge, and without any one ever fufpedt- 
ing, as indeed few of them do at this day, that the lead 
which they continued to employ occafioned any decom- 
polition of the alum, or that the mordant fo produced, 
did-not really contain all the ingredients ufed in pre¬ 
paring it. 
If cottons printed with the above-mentioned acetated 
aluminous liquor be dyed with weld or quercitron bark, 
inrtead of madder, this bafis will attract their colouring 
particles in the fame manner, and produce permanent 
yellows upon the figures where the alumine was previ- 
oufly fixed ; the other parts, being but flightly tinged, 
are afterwards eafily bleached or whitened, becaufe there 
is no mordant to hinder the fepar 3 tion or deftrudtion of 
the colouring matter of thefe dying drugs. The dying 
of yellows, however, in this way, is an European inveu. 
N G. 
tion ; the people of India having Only- given them, as 
already mentioned, by a mixture of the decodtion of the 
galls of mirobalans with alum. And, indeed, this prac¬ 
tice was followed here for fome time after the introduc¬ 
tion of the art into Europe, excepting that inrtead of the 
galls of the mirobalan tree, a decoction of French ber¬ 
ries was employed ; by which, indeed, a very full bright 
yellow was at firft communicated, but of fo fugitive a 
nature, that the ufe of thefe berries, which in fome de¬ 
gree ftill fubfifts, ought to be prohibited ; it being im- 
poflible, by any means yet known, to obtain from them 
a colour fit for any other purpofe than that of deception. 
If, inrtead of the aluminous bafis, cottons or linens be 
impregnated with iron-liquor (acetit of iron) of different 
degrees of ftrength, and dyed with madder, they will re¬ 
ceive permanent dark browns of different rtuides, and even 
a full black : and if, inrtead of iron liquor alone, it be 
mixed in different proportions with theacetit of alumine, 
the mixture will produce with madder all the (hades of 
flea-colour, purple, violet, See. But when, inrtead of 
madder, cottons or linens are printed with iron-liquor, 
and dyed with weld or quercitron bark, they receive a 
variety of olive-brown, drab, and dove colours; and if, 
inrtead.of iron-liquor alone, a mixture of it, with acetit 
of alumine, be ufed as a mordant, they will take various 
(hades of olive, olive-green, See. And, indeed, by the 
help of thefe two mordants only, (from iron and alu¬ 
mine,) ufed feparately, as well as mixed in various pro¬ 
portions, and afterwards combined with the colouring 
matters of madder and of weld, or (inrtead of the latter) 
of quercitron bark, aided by indigo, nearly all the pof- 
fible varieties and (hades of colour are now given in the 
way of calico-printing. 
Hitherto the art of calico-printing has been confined 
almoft folely to linens and cottons, which are fuited to 
it, by being'made fufceptible of a permanent union with 
colouring matters, and efpecially with fheir bafes, by 
only the common warmth of the atmofphere : and as this 
is alfo the cafe of filk, there can be no doubt but this 
might alfo be made the fubjedt of new and beautiful em- 
bellifhments in that way, which, if properly executed, 
would undoubtedly become a Entree of gratification to 
the public, and of profit to individuals. And lately, a 
fpecies of dying or ftaining, very much refembling fome 
parts of calico-printing, has been ingenioufly applied to 
woollen duffs, particularly to thofe called kerfemeres, 
for vaiftcoat patterns, &c. The colours are made to 
penetrate and unite with the wool, by placing the fluff 
fo to be printed, in the (team of boiling water, for a fuf- 
ficient length of time. 
It now only remains to deferibe the manner in which 
calico-printers perform the work. Some calicoes are only 
printed of one colour, others have two, others three, or 
more, even to the number of eight, ten, or twelve. The 
fmaller the number of colours, the fewer are the procef- 
fes. r. One of the mod common colours on cotton-prints 
is a kind of nankeen yellow, of various (hades, down to a 
deep yellowifh brown or drab. It is ufually in (tripes, 
flowers, or fpots. To produce it, the printers' befmear 
a block, cut out into the figure of the print, with acetit 
of iron thickened with gum or flour ; they apply it, thus 
charged, to the cotton; which, after being dried and 
cleaned in the ufual manner, is plunged into a pot-afh 
ley. The quantity of acetit of iron is always propor¬ 
tioned to the depth of the intended (hade. 2. For yel¬ 
low', the block is befmenred with acetit of alumina. The 
cloth, after receiving this mordant, is dyed with quer¬ 
citron bark, and then bleached. 3. Red is communicated 
by the fame procefs, only madder is fubftituted for the 
bark. 4. The fine light blues, which appear fo often on 
printed cottons, are produced, by applying to the cloth 
a block befmeared with a compofition, confiding partly 
of wax, which covers all thole parts of thq cloth which 
are to remain white. The cloth is then dyed in a cold 
indiga 
