An Improved Process and Apparatus for Testing the Presence of Colouring Matter in Wines.
Year: 1889

page_text: Date of Application, 9th Apr., 1889
Complete Specification Left, 8th Jan., 1890-Accepted, 8th Feb., 1890 - ·
PROVISIONAL SPECIFICATION.
An Improved Process and Apparatus for Testing the Presence of
Colouring Matter in Wines.
We, LOUIS MATHIEU, and JULES MORFAUX, both of Constantine, in the Republic
of France, Chemists, do hereby declare the nature of this invention to be as
follows:-
Our invention has for its object an improved process and apparatus for easily and
quickly ascertaining whether wine has been adulterated with aniline or coal tar colouring
matters.
The improved apparatus consists, first of tufts or bunches of silk held by metal
rings; second, of two test tubes provided with metal caps or covers having hooks by
which the tuft or bunch of silk can be suspended in the tubes; third, of a supporting
stand for the tubes; fourth, of a bottle containing a re-agent for treating the silk
when coloured; fifth, of a collection of the colouring matters most used for artificially
colouring wines; sixth, of a small glass funnel. The whole of these may be contained
in a portable case, with instructions for their use.
The following is the process used. The silk is white, ungummed, and perfectly
free from foreign matter, having been submitted to a special treatment consisting in
immersing it for twelve hours in a bath consisting of one part of nitric acid of a
strength of 36° Beaumé, and nine parts water, the silk being then washed in water
to remove all excess of acid. The threads or fibres of silk are then united by a ring
so as to form tufts or bunches, another ring serving to suspend the bunch from the
hook in the cover of the test tube.
The re-agent used consists of 1000 grammes of distilled water, 450 grammes of
neutral acetate of lead in crystals, and 20 cubic centimetres of glacial (crystallizable)
acetic acid. This solution is. diluted when it is to be used with ten times its volume
of water.
The tuft or bunch of silk is suspended by the hook in one of the test tubes filled
with the wine to be tested, for ten minutes. The coloured bunch of silk is then
removed and pressed between the fingers to remove the excess of liquid, and it is, then
instantly plunged into the diluted re-agent contained in the other tube.
The variations of colour of the bunch of silk in the tube are then obeserved. If. tho
wine used has been natural or only diluted with water, the colour becomes green, of
a greyish or bluish tint according to the character of the vintage.
If any red tint remains it denotes the presence of some of the numerous red dyes
obtained from coal tar, or of cochineal, carmine, or orseille.
By the improved process described, the colouring of the silk by the wine is effected
directly without the previous alkalization of the latter.
The ungummed silk is passed into the acid bath without the use of any mordant ;
and the re-agent used consists simply of a solution of neutral acctate of lead acidulated
with acetic acid.
TIL
حيم
1
1 1000

page_text: COMPLETE SPECIFICATION.
An Improved Process and Apparatus for Testing the Presence of
Colouring Matter in Wines.
We LOUIS MATHIEU and JULES MORFAUX both of Constantine in the Republic of
France Chemists do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and by the
following statement :-
The object of this invention is to provide means for testing wine to ascertain the
presence therein of colouring matter derived from coal tar or aniline or from cochineal,
carmine or orseille.
- : 1
The improved process consists in immersing silk prepared as hereinafter mentioned
in a sample of the wine to be tested without any previous treatment of the latter by
alkalization or otherwise, removing said silk after a certain period of immersion,
pressing the same to remove excess of liquid and without using any mordant,
immersing it immeadiately in a dilute aqueous solution of neutral acetate of lead,
acidified with acetic acid. Red colour remaining in the silk after the second immersion
will indicate the presence of the colouring matter or matters aforesaid.
The apparatus and means for carrying out this process are preferably as follows.
The apparatus consists principally of tufts or bunches of silk held by metal rings,
two test tubes provided with metal caps or covers having hooks from which the tuft
or bunch of silk may be suspended in the tubes and a suitable stand or holder for
said tubes. To these may be added, a bottle containing the reagent for treating the
silk after immersion in the wine, a collection of the colouring matters most used for
artificially colouring wines for comparative tests and a small glass funnel or graduated
measure.
The silk should be white, ungummed, and perfectly free from foreign matter
to which end it is especially prepared by immersion for twelve hours in a bath con-
taining one part of nitric acid of a strength of 36 degrees Beaumé and nine parts
water and thorough subsequent washing in water to remove the free acid.
The threads or fibres of silk are then united by a ring so as to form tufts or bunches
another ring or hook'being attached for suspending the tuft on the hook in the cover
of the test tube.
The reagent used consists of 1000 grammes of distilled water, 450 grammes of
neutral acetate of lead in crystals and 20 cubic centimeters of glacial. (crystallizable.)
acetic acid. This solution is diluted when it is to be used, with ten times its volume
of water.
'
The tuft or bunch of silk is suspended by the hook in one of the test tubes filled
with the wine to be tested for ten minutes. The coloured bunch of silk is then
removed and pressed between the fingers to remove the excess of liquid and it is
then instantly plunged into the diluted reagent contained in the other tube.
The variations of colour of the bunch of silk in the tube are then observed. If the
wine used has been natural or only diluted with water the colour becomes green, of
.a greenish or bluish tint according to the character of the vintage. If any red tint
remains it denotes the presence of some of the numerous. red dyes obtained from coal
tar or of cochineal carmine or orseille.
The accompanying drawing illustrates the principal portions of the apparatus
A being the tuft of silk, C and D the respective test tubes for the wine and the reagent,
E E the covers for the said tubes, G the 'hooks therein and H the stand or holder for
supporting the tubes.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The process or method of testing wine consisting in immersing silk in said wine
and afterwards in an aqueous solution of neutral acetate of lead, acidified with acetic
acid for the purpose set forth.

page_text: 2. The apparatus consisting in the combination of two test tubes, covers therefor, a
stand or holder for said tubes and a tuft of silk adapted to be suspended from said
covers substantially as and for the purpose set forth.
Dated this 8th day of January 1890
HERBERT & Co..
18, Buckingham Street, Strand, London, W.C., Agents to Applicants.