DYEING. 
O/' dyeing- Cotton and Linen green. 
Cotton and linen are scoured in the usual 
way, and then first dyed blue ; after being 
cleaned, they are dipped in the weld bath 
to produce a green colour. The strength 
of the blue and yellow is proportioned to 
the shade of green wanted. But as it is 
difficult to give cotton velvet an uniform 
colour in the blue vat, it is first dyed yellow 
with turmeric, and the process completed 
■ 1>y giving it a green by sulphate of indigo. 
The different shades of olive, and drakes- 
neck green, are given to cotton thread, 
after it has received a blue ground, by gall- 
ing it, dipping it in a weaker or stronger 
bath of iron liquor, then in the weld bath, 
and afterwards in the bath with sulphate 
of copper ; the colour is lastly brightened 
with soap. 
Yellow colours are rendered more in- 
tense by means of alkalies, sulphate of lime, 
and ammoniacal salts, but become fainter 
by means of acids, solutions of tin, and 
alum. 
Of dyeing Wool purple, violet, and lilac. 
Violet, purple, lilac, dove colour, and a 
great variety of other shades, are produced 
by the mixture of red and blue, according 
to the proportions of the substances em- 
ployed. For violets, a deep blue ground is 
given, and for purples a lighter blue ; in 
lilacs and similar colours, botli the red and 
blue are light. 
For violets and purples, the stuff should 
first be dyed a light blue, not deeper tlian 
sky blue ; it is then boiled with alum and 
two-fifths of tartar, and is afterwards dip- 
ped in a bath composed of nearly two-thirds 
the quantity of cochineal required for scar- 
let, with the addition of tartar. The same 
process is followed as for dyeing scarlet. 
It is common to dye tiiese colours after the 
reddening for scarlet, making such addi- 
tions of cochineal and tai’tar, as the inten- 
sity of the shade may require. 
For lilacs, dove colours, and other lighter 
shades, the stuff may be dipped in the bath 
which has served for violet and purple, and 
is somewhat exhausted, taking care to add 
a proper quantity of alum and tartar. For 
reddish shades, such as peach-blossom, a 
small proportion of solution of tin is added. 
It may be observed in general, that though 
the proportion of cochineal is less in lighter 
shades, the quantity of tartar must not be 
diminished. 
A less expensive process is recommended 
by M. Poerner for these colours : he pre- 
pares the stuff by boiling it an hour and a 
half, with three ounces of alum for every 
pound of it, and leaving it a night in the 
liquor after it is cold ; he makes the bath 
with an ounce and a half of cochineal, and 
two ounces of tartar, for every pound of 
stuff, boiling it three quarters of an hour, 
and then adding two ounces and a half of 
sulphate of indigo in the above proportion 
to the stuff ; he stirs the bath and makes it 
boil gently for a quarter of an hour, and 
thus obtains a very beautiful violet ; he in- 
creases and diminishes the indigo in all pro- 
portions from five drams to five ounces, to 
each pound of stuff, according to the shade 
wanted; he also reduces the quantity of 
cochineal, but never below an ounce to the 
pound, because the colour would then be 
too dull: he varies the proportion of tar- 
tar, and prepares the stuflF with different 
quantities of solution of tin. 
A purple colour, as well as some other 
shades, may be given to wool by logwood, 
with the addition of galls, but the colours 
thus obtained are not permanent. M. De- 
croizille discovered a process by which a 
durable dye may be procured from log- 
wood, of which the following is an account. 
The mordant used was a solution of tin in 
a mixture of sulphuric acid, common salt, 
and water ; to which were added red aci- 
dulous tartrite of potash, and sulphate of 
copper. 
If the wool is to be dyed in the fleece, 
it will require a third of its weight of this 
mordant, but for cloth a fifth will be suffi- 
cient. A bath is to be prepared as hot as 
the hand can bear, with which the mordant 
is to be well mixed, and the stuff is to be 
dipped in it and stirred ; the same tempe- 
rature is to be kept up for two hours, and 
increased a little towards the end; after 
which the stuff is to be taken out, aired, 
and well washed. A fresh bath of pure 
water is prepared at the same temperature, 
to which a sufficient quantity of the de- 
coction of logwood is added; in this the 
stuff is immersed and stured; the heat is 
then increased to the boiling temperature, 
and continued so for fifteen minutes, after 
which the stuff is taken out, aired, and 
carefully rinsed. If the decoction of one 
pound of logwood has been used for every 
three pounds of wool, and a proportionate 
quantity for stuffs that require less, a fine 
violet colour is produced ; to which a suf- 
ficient quantity of Brazil wood imparts the 
shade known in France, by the name of 
prune de Monsieur. 
