DIPPING, 
acts very ites 
at ae a even eight immerfions. The feco 
vats may be ftronger, and fo on to the laft, which m 
He trong of all. Dark blues may be dipped and finylhed 
me vat, but it is more convenient to pafs them in 
fu eectian through a feries difpofed in a line in the manner we 
have be defcribed 
When the piece is well 
vat muft be well fkimmed before the piece is ny The 
furface of a blue vat is always covered w of revi 
ved ee more or lefs thick, oo to che rength of 
» and adheres to the cloth i 
patches, producing eee in the dye, efpecially in the 
firft v When fkimmed, the catags ° the vat is dark 
green, a the blue film ew min 
fhould not be removed, ee. till ae frame is oat: 
immerfion. 
or fix minutes the cloth has fully imbibed the dye, 
and itl advantage is = ained in general by keeping it longer 
in the v rame is then lifted out, and placed flant- 
wife in Tuch a manner, an all the liquor which drains from 
the piece falls down into the vat again. 
ie atmolphere, becomes revived, a nd in five minutes the 
cloth appears uniformly bagi it is ar ready a pee 
immerfion. Six tes in, utes out, i 
x 
general rule for dipping dark Saas as che sc ‘will In a 
time have acquired the full effect of the vat, e green 
will alfo go off in little more than five cae pie h the 
tering a piece reen, 
is, as might be eee that the ae will be the eset the 
indigo not havin repens 
with the reft of the 
In dipping dark Gas the firft dip is a moft important ; 
and if it fails, the work is inevitably ru pak if the 
vat be too ftrong, the whites will a hever be a 
d 
e, the goods will {carcely ever be 
hirdly, if either from the pafte bein 
too weak, or no 
int the firft four 
fact ou aa to be a men vard ; but if unavoidably it 
fhould happen that the leading vat is too ttrong, there is no 
other remedy than fhortening the time of the dip, and 
keeping the frame in i or mab minutes in lieu of fix, till 
the vat becomes reduced in ftren 
e€t bleaching, cadet impurity in the cloth, and 
long ae partial expofure to heat and air, are amongft the 
caufes which contrib te moft to prevent the cloth from re- 
ceiving the blue dye. 
utes oe 
is the praCtice with many printers to give the cloth in- 
b 
mee ae how purpofe an extra ‘ai abe sae see y boil- 
ing in ee or a guns of c nfalt. If 
the ae plese @ bas been perfeét, the "Brit i is wholly 
unnecefiary, and ie fea d abfolutely ufelefs 
Cloth that has been well bleache: mete b ‘long 
keeping, 
and partial expofure to the air, duft, a 
other accident’ im 
other attendant operations are ufeful, but 
clean, swell bleac cs, = recently bleached cloth has no need 
of any fu a prepar 
If t afte be $6 "ftrong, that is, if it contains too much 
fulphate, acetate, or nitrate of co pper, it is liable to itart 
or run in the firft — efpecially when laid on in large bodies. 
This evil, if no 
being too weak, and confequently containing too little lime 
in folution, asd m 
ime, or ror greater ftrength to 
the vat, the pafte {till continues to run, it is a fign the fo- 
ution of copper is too ftrong, and the quantity mutt i im~ 
mediately be diminifhed. 
the ia is ad off after the firft dip, the frame 
Ipping, t 
goods, after a certain time 
merfion, or even two or three, i get them up to the ftrength 
of the firft pieces that were entered. 
The ftrength of a blue ae is not exhaufted inthe fame 
anner as the weld or madder bath, by the abftraGtion of 
the colouring matter from he folution, by the fuperior affi- 
nit t ordant on t When a piece of cloth is 
immerfed in ie e indigo ae it becomes penetrated in five or 
fix minutes compleatly with the dye, and will gain nothing, 
by being fuffered to remain longer see is neceflary for this 
purpofe. When taken out, it catries w 
3 
ac 
again into the vat, and pours down in {mall ftreams, thus 
expofing the folution compleat tly 
into = — is for the purpofe of dyeing, no better than fo 
uc a ery frame ay entcred thus ae es 
preceicebs of the colouring from matter two, thre 
four gallons of ve folution, che vat, efpecially the ieatie 
one, foon becomes reduced in ftre engi e fecond, third, 
and fucceffive vats, are weakened in ame manner, and 
alfo by the exhaufted liquor of the nee s, which at every 
dip after the firft, is exchanged, as it were, for the freth and 
ga a of the vat it 1s immerfed in. 
e goods have Spee the laft dip, and have ac- 
ia hee full fhade of colour, they are taken off the 
hooks, and well winched in clean water; they are then, 
the fucceflive operations of wathing and hot wa 
peated as occafion may require, freed fr 
ouring 
