1023 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[June 21, 1S71- 
cylindrical percolator, and continue to add this mix¬ 
ture until eight fluid ounces of the percolate has 
passed; to this add the remainder of glycerine, pre¬ 
viously mixed with the Curasao, and thoroughly mix 
the whole together. This will afford, by careful 
manipulation, a very fine preparation, miscible with 
any of the officinal syrups or tinctures, and possess¬ 
ing all the medicinal properties of lupulin. Dose, 
for an adult, one teaspoonful, representing ?b grains 
of lupulin.— Amer. Journ. of Pharmacy. 
THE CHEMISTRY OF CALICO PRINTING. £ 
BY JAMES BLAIR. 
(Continued from page 1010 .) 
Clearing has for its object the removing of any taint 
or soiling contracted in the former operations, and also 
has a brightening action on some colours. It consists in 
padding the goods in a solution of bleaching powder 
at to f° Tw. (the less whites the stronger the liquor), 
then passing the goods through blue liquor, i. e. ultra- 
marine and 110. The ultramarine may be mixed with the 
bleaching liquor. The goods on passing from the bleach¬ 
ing and bluing liquor are dried by passing over steam 
cylinders, then starched with solution of fine wheat starch 
and dried (if muslins tentered), calendered, folded, 
pressed. 
Mordanted or Dyed Colours .—In these colours various 
metallic salts are printed on the cloth, and means 
adopted for rendering their base permanently fixed. 
This being accomplished, the goods are immersed in a 
bath containing the colouring principle, which in the 
operation of dyeing combines with the mordant in the 
cloth, forming a lake or other chemical compound with 
it. The principal styles of this class are:— 1 , Chrome 
oranges and yellows. 2, Logwood blacks. 3, Madder 
work. 4, Garancine work. 
The first are, of course, produced by a lead salt and a 
soluble chromate. The other styles involve the use of 
madder, logwood, garancine, alizarine, Lima wood, bark, 
sumac, quercitron, galls, flavine, Persian berries, in the 
dye bath; salts of iron, alumina and tin, individually 
or mixed, constituting the mordants. 
Chrome Orange .—The cloth is padded with solution of 
MgOSOg at 12 oz. per gallon and dried. The orange 
mordant, the basis of which is acetate of lead, is printed 
on, and by the Mg 0 S 0 3 converted into the insoluble 
sulphate of lead in the fibre of the cloth. 
The cloth is then passed through a cold bath of 35 lbs. 
bichrome -f- 112 lbs. salt + HO till 26° Tw., which pro¬ 
duces the yellow and insoluble chromate of lead. 
The cloth is then worked in a vat of bichrome at 
40° Tw. and CaO, boiling, which changes the yellow 
chromate into the orange chromate of lead; then cooled 
by rinsing in cold water, and then rinsed in lime water, 
rinsed in water, and dried. 
Chrome Yellows are produced in the same way as the 
orange, but the treatment in the hot chrome and lime 
vat and the washing in lime water is omitted. 
The operations of printing and dyeing madder, garan¬ 
cine and logwood are in some degree analogous, so may 
be conveniently described together. The mordants re¬ 
quired for this style are acetate of iron and alumina, and 
chloride of tin, catechu, nitrate of copper, chloride of 
iron; the dyes—logwood, Lima wood, bark, sumac, 
quercitron, galls, flavine and Persian berries. 
Mordants .—Acetate of iron, supplied to the printer in 
concentrated solution at 32° Tw., is made by passing the 
crude pyroligneous acid obtained from wood distillation 
direct from the still over iron turnings in the condenser. 
It invariably contains tarry impurities, which, however, 
in no way interfere with its usefulness ; diluted less or 
more with H O it furnishes all the shades of black, purple 
and lilac produced by dyeing with madder, logwood, 
garancine, alizarine or mixtures of these dyes ; thus 
black—1 volume EeOA and 1 volume HO = FeOA at 
16°, thickened by boiling with flour + 2 oz. A S 0 3 ; purple, 
weaker according to shade wanted; purple standard, 
FeO A, at 12° F., from 1 of purple standard to 8 of gum 
water to 1 to 36; covers 1 to 6 to 1 to 22 ; pads 1 to 24 
to 1 to 54, figure thick with black gum; covers and 
pads boiled with flour. The solutions of acetate of iron 
are thickened for printing by flour or British gum. 
Acetate of alumina is made by neutralizing sulphate of 
alumina solution with solution of acetate of lime, and is 
used neutral, or with a trace of free alum. Acetate of lime 
is made by saturating slaked lime with the crude acetic 
acid from wood distillation ; it always contains tarry 
matters, which, for most work, are harmless. Cake alum 
supplied in slabs is nearly pure A1 2 0 3 S0 3 , and must be 
free from iron. 
This mordant, more or less diluted, furnishes all shades 
of red and pink with madder, garancine or alizarine. 
Where a very bright red is wanted, chloride of tin is 
mixed with the alumina mordant. 
For pinks, the tin is sometimes omitted. The mor¬ 
dants are prepared for printing by thickening with 
starch or British gum. 
Mixtures of alumina mord. and iron mord. give all 
shades of chocolate from madder, garancine and alizarine. 
Catechu.—The valuable colouring principle of this 
substance is catechin, C-H c 0 3 , which bears a resemblance 
to tannin. 
This substance furnishes, with small proportions of 
CuON 0= and acetate of alumina, the various shades of 
brown. 
A standard solution is made of catechu in H O, with 
NH 3 CI and acetic acid; this is thickened with gum 
gedda, and Cu0N0 5 +A1 2 0 3 S0 3 added just before 
printing. 
The same colours, with FeCl substituted for ALO ;i 
acetate, furnish shades of drab. 
Dyes. 
Logwood contains hematoxyline C 1 ( 5 H 14 0 6 ; it is so¬ 
luble in IIO and alcohol, and crystallizes with three 
atoms of water in colourless crystals. Air- or oxygen 
do not act upon it, but in presence of NII 3 it is converted 
into hematein, C lf) H 10 O 5 , which combines with the NH 3 , 
forming hemateate of ammonia, thus C lf) II 14 O r) + 0 + 
NH 3 =C 16 H 9 (NH 4 ) 0 5 + 2H 2 0 ; hematein, the actual 
colour is soluble in II0. It is an amorphous brown-red 
body, and forms crystallized salts with the alkalies and 
insoluble lakes with many metallic salts, thus, the lead 
lake is blue, the copper violet, tin violet, iron black,— 
these lakes have considerable stability. 
Madder ( Rubio, tinctoria ).—The valuable constituents 
of madder-roots are—rubian, C 2 g H 34 0 15 ; alizarine, 
C 10 H n O 3 ; purpurine, C 30 H 20 O 10 .; and erythrosyme, a 
nitrogenous body. 
Rubian, C 28 H 34 0 15 , is regarded as the primary source 
of the valuable .colouring-matters in the madder root. 
It is soluble in cold water and in alcohol, yielding 
yellow-coloured solutions having a bitter taste. By fer¬ 
mentation produced by the action of erjifirosyme, and 
also by sulphuric acid, rubian is converted into alizarine 
and purpurine, glucose and resinous matters being also 
formed at the same time. 
Alizarine, C 10 II 6 O 3 .—This is the valuable colouring- 
principle of madder. It does not exist to any great ex¬ 
tent in the root, but is a product resulting from the de¬ 
composition of the rubian by fermentation. Alizarine is 
insoluble in cold water, but soluble in boiling water, 
bisulphide of carbon, naphtha, etc. It sublimes at 228° 
F., and is obtained in golden-yellow needles. It forms 
stable compounds with alumina, iron and tin, and these 
lakes are insoluble in water and even in solutions of soap. 
Purpurine, C 30 H 20 O 10 . is another colouring-matter 
resulting from the decomposition of rubian. It forms 
definite compounds with alumina, iron and tin. These 
