IMPROVEMENTS IN OBTAINING EXTRACTS FROM MADDER FOR DYEING AND PRINTING
Year: 1857

page_text: Sealed the 20th March 1857, and dated the 13th January 1857.
PROVISIONAL SPECIFICATION left by the said François Auguste Verdeil
and Emond Michel at the Office of the Commissioners of Patents,
with their Petition, on the 13th January 1857.
We, FRANÇOIS AUGUSTE VERDEIL, of No. 30, Rue St. Sulpice, in the City
of Paris, and EMOND MICHEL, of No. 4, Quai Imperial, Puteaux, (Départ-
ment of the Seine), France, do hereby declare the nature of the Invention
for "IMPROVEMENTS IN OBTAINING EXTRACTS FROM MADDER FOR DYEING AND
PRINTING," to be as follows:-
This Invention has for its object improvements in obtaining extracts from
madder. For this purpose the madder root is roughly pounded and soaked
for several hours in hot water; the water is then drawn off and the root
again soaked for several hours in another smaller quantity of hot water.
When this water is drawn off the madder root is digested with cold potash
water; this liquid is then drawn off, and the madder root repeatedly boiled
with water, so as completely to extract the madder. The liquids resulting

page_text: from these processes are neutralized by an acid (by preference sulphuric acid),
and they are then concentrated by evaporation; more acid is then added, and
so causes a precipitate, which carries down with it the coloring matter. If the
precipitate formed on the addition of acid is not sufficiently abundant to carry
down all the coloring matter, then, before adding the acid, white of egg
dissolved in alkaline water may be added, so as to increase the amount of
precipitate. The precipitate thus formed is then separated by filtration and
dried, when the coloring matter contained therein is dissolved in boiling wood
spirit or alcohol. The saturated solution is neutralized by a small quantity of
ammonia and then distilled, and the residue which remains in the retort is
the extract of inadder.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said François Auguste Verdeil, and Emond Michel in the Great
Seal Patent Office on the 8th July 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, FRANÇOIS
AUGUSTE VERDEIL, of No. 30, Rue St. Sulpice, in the City of Paris, and
EMOND MICHEL, No. 4, Quai Imperial, Puteaux, Department of the Seine,
France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of January, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
François Auguste Verdeil and Emond Michel, Her special licence that we,
the said François Auguste Verdeil and Emond Michel, our executors, adminis-
trators, and assigns, or such others as we, the said François Auguste Verdeil
and Emond Michel, our executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN OBTAINING EXTRACTS FROM MADDER FOR DYEING AND PRINTING," upon
the condition (amongst others) that we, the said François Auguste Verdeil
and Emond Michel, our executors or administrators, by an instrument in
writing under our or their hands and seals, or under the hand and seal of
one of us or them, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed, and

page_text: cause the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Francois Auguste Verdeil, on behalf of
myself and the said Emond Michel, do hereby declare the nature of the
said Invention, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement
thereof, that is to say:-
This Invention has for its object improvements in obtaining extracts from
madder for dyeing and printing, and consists in crushing the madder root and
extracting it with an alkaline liquid, from which the coloring matter is after-
wards precipitated by an acid. The crude coloring matter thus obtained is
dissolved in alcohol or wood spirit, and the solution is distilled to again
separate the alcohol or wood spirit; the pure coloring matter remains in the
retort.
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe in detail the process which
I prefer to employ.
The madder root is swelled by soaking it in water slightly acidulated with
sulphuric acid, and is crushed by passing it between rollers, in order to separate
as much liquid as possible from the crushed root; it is pressed by means of a
hydraulic press. The crushed root is, after it has been pressed, placed in a
suitable vessel with a solution of potash or soda, marking from two to four
degrees Beaumé; a sufficient quantity of the solution being used just to
cover the crushed root, which is left to soak for 48 hours or longer, when
it is again pressed with the hydraulic press, and the resulting liquid is
collected to be treated as is herein-after described. The root is then
again soaked as before in an alkaline liquid, which should be of about half
the strength of that first employed, and the liquid is again pressed out.
The alkaline liquids resulting from the two pressings, or more, if wanted,
are mixed together, and a sufficient quantity of sulphuric acid is added to
precipitate the whole of the coloring matter. The precipitate is collected on a
filter and well pressed, and then dried, and dissolved in boiling alcohol or wood
spirit; the solution, having been rendered clear by filtration, is put into a still,
and the alcohol or wood spirit is distilled over, care being taken to employ no
more heat in this operation than is necessary to avoid injuring the coloring
matter, which is then ready for use.
In order to dye a fabric with this extract, it is only necessary to dissolve it
in water and to immerse in the solution the fabric to be dyed, the fabric
having been previously mordauted in the ordinary way, by which process the

page_text: dyeing is so quickly made that one or two minutes hardly are wanted. When
the extract is to be used for printing, it is dissolved in water and precipitated
with acid. The precipitate is dried, mixed with a suitable vehicle, and the
fabric is printed with it in the ordinary way.
In witness whereof, I, the said Francois Auguste Verdeil, have hereunto
set
my hand and seal, this Sixth day of July, in the year of our Lord
One thousand eight hundred and fifty-seven.
Witness,
T. BASSET.
FS VERDEIL. (L.S.).