416 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [November 13,1871. 
the spectrum, having between them a hand of green light; 
whilst alizarine exhibits, on analysis, a band of absorp¬ 
tion in the yellow, and another narrower one between 
the red and the orange. 
Professor Schiitzcnberger, by treating commercial pur- 
purine successively with alcohol and benzine, unfolded 
it into four different substances, to which he assigns the 
following formulae :— 
Alizarine . . . 
1. Purpuroxantliinc 
2. Purpurine . . 
3. Orange matter . 
c 20 h 12 o 6 . 
C 20 H 12 O 6 or C 20 H 14 O G . 
C 2U H u 0 7 or oxy-alizarine. 
C 20 H 1G O 9 or hydrate of 
purp urine. 
4. Pseudopurpurine . C 20 H 12 O 9 or oxy-purpurine. 
_ I shall now call your attention to a very remarkable 
discovery, recently made by the late Professor Bolloy, 
viz. the conversion of purp urine into alizarine. If pur- 
purine is heated in the atmosphere, as stated above, it is 
nearly all sublimed, leaving only a small amount of 
carbonaceous residue, but if heated in sealed tubes, at a 
temperature of 400°, it forms a carbonaceous mass from 
which water extracts alizarine. Under the influence of 
the high temperature, the purpurine loses an equivalent 
of oxygen, and is converted into alizarine. This reaction 
appears to confirm the opinion oUM. Decaisne, that the 
madder plant contains only one colour-giving principle, 
which under the oxidizing influence of the atmosphere 
becomes converted, first, into alizarine, then purpurine, 
and afterwards into the still more highly oxidized com¬ 
pounds. 
The difficulty and expense experienced by calico- 
printers in brightening their colours and obtaining pure 
whites in madder-dyed goods, attracted many years ago 
the attention of scientific and practical men, and any 
process by which these difficulties might be overcome was 
anxiously looked ,for. The discovery of MM. Robiquet 
and Collins, that the colour-giving principle was not de¬ 
stroyed by sulphuric acid, was the step in that direction, 
and led M. E. Schwartz to observe that the carbonaceous 
mass of Robiquet, if carefully washed and neutralized, 
could be used as a dye-stuff. MM. Lagier and Thomas 
improved upon this, and introduced, in 1839, an article 
which is now extensively used by calico printers and 
named garancine, and now is prepared as follows 
Madder, either unwashed, or, better still, washed -with 
cold water, is mixed with one-third of its weight of sul¬ 
phuric acid, which has been previously diluted with 
water till it marks 10° Twaddle; it is then boiled for 
four or five hours, and the mixture run on to woollen 
filters and washed till only a mere trace of acid remains. 
It is then either removed or washed once with a very 
weak. solution of carbonate of soda, submitted to hy¬ 
draulic pressure and then introduced into drying stoves. 
One hundred parts of madder yield from thirty-four to 
thirty-seven of garancine. Garancine is a fine powder 
of a light brown colour, and has a dyeing power four 
times as great as the original madder. It does not give 
as good blacks as. madder, nor are its purple, red and 
pink so fast, but its purple is brighter, and the whites 
are obtained .pure without soaping, it being only neces¬ 
sary to substitute a slight clearing liquor, composed of 
an alkaline, hypochlorite of soda, to which is added a 
small portion of sulphate of zinc. 
In 1852, Messrs. Pinckoff and Schunck effected an im¬ 
provement in the manufacture of garancine, their pro¬ 
duct being known in England under the name of com¬ 
mercial alizarine ; but on the Continent it is better known 
as Rtncoffine. Their process consists in submitting ordi- 
nary garancine to the action of high pressure steam of a 
temperature of 300° F., which, whilst it does not act on 
the alizarine contained in the garancine, destroys two 
other colouring matters which are present. These Dr. 
Schunck has isolated and examined, and named Ruber- 
Unc and Rerantine. They are of a peculiar resinous 
nature, and spoil both the whites and the purples, which 
are fixed along with alizarine in the dyeing process. 
The employment of commercial alizarine is especially 
advantageous in the production of purples, which are 
faster and more brilliant than those produced by ordi¬ 
nary garancine. The cloth also does not require either 
soaping or cleansing. 
M. Pernod has, within the last two or three years, in¬ 
troduced a madder extract, which is at the present time 
extensively used in Lancashire as a topical colour. This 
term is applied to a colour which is printed on a fabric, 
and afterwards fixed by steaming. By this method, 
bright and fast colours are introduced in printed goods, 
producing much more effective designs than could be 
effected if the goods had to pass through a dye-beck and 
afterwards be washed with large quantities of water. 
Some splendid specimens of this class of printing were 
to be seen at the last Universal Exhibition, 1867. 
To prepare the extract, garancine is lixiviated till 
completely exhausted, with a nearly boiling solution of 
sulphuric acid, containing five parts of acid to a thousand 
of water. On cooling, an orange-red precipitate falls, 
to the bottom of the vessel, which, when collected and 
thoroughly washed, constitutes an extract ready for use. 
The products of M. Leitenberger and Messrs. Schaaffer 
and Lauth may be substituted for this extract. 
As the employment of these extracts is the most im¬ 
portant improvement recently introduced into calico- 
printing, I will give the three following recipes for their 
application :—To produce dark red, take 8 lb. of extract 
of madder, 4 lb. acetic acid and 1^ lb. starch. Boil 
these in an earthenware vessel, and, when cold, add to- 
six measures of the above one of acetate of alumina and 
a very small quantity of Gallipoli oil, say 1 per cent. 
For a pale red, take 4 lb. of extract of madder, 2 lb. of 
acetic acid, 10 quarts of gum Senegal water, and 1 pint 
of acetate of alumina. To obtain a purple, take 1 pint 
of extract of madder, half pint of acetic acid, half pint of 
water, and 3 oz. starch; boil, and when the mixture is- 
cool, 5 oz. measure of acetate of iron of 24° Twaddle 
and 5 oz. of -water. To produce a chocolate, proceed as 
in the last recipe, substituting acetate of chromium for the 
acetate of iron. 
The above mixtures are printed on cloth by means of 
engraved copper rollers, and are then dried and sub¬ 
mitted to dry high-pressure steam for one or two hours, 
when the colours have become fixed on the fabric. After 
being- slightly soaped, to remove all excess of colour, the 
prints are stiffened and ready for the market. 
Although I have now concluded my lecture on madder 
as a dye-stuff, and have already exceeded the time 
allotted to me, I hope you will allow me a few minutes 
more, to enable me to give an outline of the processes by 
which madder styles are produced, the more so as there 
may be some persons present who are not aware how 
madder and garancine prints, now manufactured in 
such enormous quantities and in such general use, are 
produced. 
To effect this, the ordinary white calico, as sold in 
shops, is not sufficiently deprived of its impurities to be 
employed in madder or garancine styles ; it has, there¬ 
fore, to undergo further bleaching operations. The calico, 
so extra bleached, is then printed by means of copper- 
rollers, on which the pattern to be produced is engraved- 
This roller leaves on the calico a red, purple or choco¬ 
late mordant; that is, for red, a sulpho-acetate of alu¬ 
mina, or red mordant; for purples, violets and blacks, 
an impure acetate of protoxide of iron, known in the 
trade as pyrolignite of iron or black liquor; and for cho¬ 
colates a mixture of these two mordants. 
After this operation the pieces undergo a process tech¬ 
nically termed ageing. This was formerly effected by 
spreading out the pieces and hanging them in‘a room 
for three or four days, so that the acetate of alumina 
might lose part of its acetic acid, and the iron mordant 
nearly the whole of it, thus liberating the oxide of iron, 
and enabling it to undergo partial oxidation. 
