DIPP 
The firt is the fimpleft and mot economical mode; but 
it requires certain precautions which the other docs not. In 
the firft place, before the fteam is a admitted into it, the boiler 
fhould be blown, that is, compleatly emptied of air; for if it 
fleam a vat, the indigo will be 
he fe 
when cold, is only of t oo oper ftrength, the adm:flion of 
fo much team, and confequently cf condenfed water, as will 
be n eceflary to raife it to the temperature re ied, will 
ees it pe ; and laftly, fome inconvenience may 
arife from t eae of condenfed water, un- 
efs due nae be made before it is admit ed, and care 
be taken ne rn it in ee. vat is ruil. 
The fecond mode is fubje& to none of thefe inconve- 
niences. vat can neither be weakeued by air from t 
he r 
boiler, nor by soudedl4 water, fince the heat is aie 
wholly through the cafing. The expence, however, is very 
angio ; “till it is greatly preferable to the plan which 
e printers have adopted, of conitruéting caft iron vats, 
a heating them - fae built undern ipaee 
The t a aaa at which they can be employed, varies 
sar panes e kind of rad = the el ach the 
paft polletfes ei refifting a hot v 
From 6o to 80° will be f ee for moft purpofes, and a 
vat of tolerable ftrength will, at the latter temperature, pro- 
duce a good blue in ten or fifteen feconds. 
Of coloured Pafle. 
By mixing both colouring matter a -mordant bi - 
ies we obtain paftes which a t the e time com 
cate colour to the Ae and refit die ‘the; a on aly 
eu - peal of dyeing, but enabling us to form com 
binat of colours, incompatible by any other pro cefs. 
This ie ch of blue dipping is er in its infancy, and tittle 
has yet been done towards its perfeétion. e fhall there- 
fore have little elfe to do in eae of this part of our fub- 
je, but to ftate the few facts on w ich 3 founded, and 
fuggett ae hints for its future improvem 
If a folution of fulphate or acetate of iron aie mixed w 
the re or pafte for white, it will, when 
off, leave a buff or orange ftain, no 
but a pucaee and sae in fome cafes. 
r ae 
er. 
d co 
s by =. cena pepe matters with the 
per pee proper for fixing them on cloth, and alfo with fub- 
face which have ce property a Pia the biue dye, 
various coloured pa eae = is obtain 
The folutions o ee forming combinations 
with moft colouring erie which are but aay affeGted 
by acids, feem pra to be cages — ompo- 
fition of paftes of this deferi ae ao tia de- 
itroys the refifting power of inet of ame by de-oxyge- 
nating them; but the nitro-muriate, or highly oxygenated 
folutions, produc irae a contrary effe& ; they are thefe 
which fhould dence be tried. 
Of ae Blue. 
The procefs for a blue dipping confifts in applying 
finely gro eer adigo, in its crude and undiffolved ftate, upon 
the cloth, and Big : by alternate anne flee in folutions 
of fulphate of iron 
The fame thing aes ple upon the cloth, that is effected 
ING. 
in the ordinary blue vat baa indigo is ciflalved in both 
cafes the indigo is deeoxygenated, and prepared for folution 
e the copperas, and aft dae diffolved a the lim 
The ae _ es of colour _ eres blue io g are 
c g re or lefs, the ftandard colour, 
rt. 
ecanee. ae) of 
and 5 lbs. of jimi 
eae. is nearly oe add two a . ae oo folu- 
tion of a renege 1, and grind a few 
2d. Prep a folution of iiphate of; iron or diffolving 
2 \bs. ina alle n of water, adding a quarter of an ounce of 
pot-athes, and fuffering the eda rca if there is any, to 
0, 1) with as much of 
O a proper con- 
ood pen as, 
€ 
a: 
: So 
i) 
Whe ipp ped 
oF back lye in _ bo 
For pale biue uce the fandard with 10, 15, or 20 mea= 
{ures - de arene a copperas, and an equal quantity of 
acetate of iron, or common iron liquor reine ith gum. 
With 50 en 
Vv via) the _ penne bloc 
sad will not work in a por ia ae cetate of iro on 
e thic kened with tarch,, or Gow oe ound u 
of ne Mandara 
y 
otke la 
preterced to fteel o we clean 
and give a fine neat capt 
The vats are of the fam ae rm, and erleg of the fame 
éimenfione, as thofe before defcribed ; the 
ith lead ; wood, or tt 
the plate aceh better, 
thofe of indigo. a. copperas 
vat, and a lime vat eae 3 or when the mode of dipping 
allows it, a lime vat between two Pal gabe vats, ee 
yltem in which two frames are worked; the lime vat being 
thus We contantly employed, the a ~ ay ana 
nate The copperat vats are di 
Fonte ths, according to the work intended tobe acne, ; hoa 
thick goods, fuch as Marfeilles quilting, &c. require ftronges 
vats than caiicoes aa muflins. The firit a the folu-~ 
tion to be gravity 1040, the lat 
Thefe are ce mot economical poiuts, bie good w 
d 1050. Lave pe 
e and faint, though even ; 
be uneven, fome parts cae 
very deep and tull, and others meaily and {po 
The livne vats are fet with fine fitted ate line aia: 
ane in the proportion of 150 lbs. to 1000 gallons of 
v Wh en the pieces are hooked, and: properly arranged on 
the trame, they are aii firft into the lime, and the dip- 
ping aaa as follow 
. Entry in fe lime vat 5 minutes. 
in Copperas vat 30 
In hime va 
in ai vat 30° 
in lim 
in copes vat fe 
in lime vat 
During the frlt five minutes in the lime, the frame mu 
a ae hei or eae Bp and down, then drawn up and 
and at every aber dip, 
is erell bed > oe the frame isentered, When enter . 
SOM PY ps 
