IMPROVEMENTS IN THE TREATMENT OF CERTAIN DESCRIP- TIONS OF WINE FOR THE PURPOSE OF PURIFYING THEM AND IMPROVING THEIR QUALITY
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by John Louis William Thudi-
chum at the Office of the Commissioners of Patents, with his
Petition, on the 27th November 1875.
I, JOHN LOUIS WILLIAM THUDICHUM, of 11, Pembroke Gardens,
Kensington, W., in the County of Middlesex, Doctor of Medicine,
Scientific and Analytical Chemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE TREATMENT OF CERTAIN DESCRIP-
TIONS OF WINE FOR THE PURPOSE OF PURIFYING THEM AND IMPROVING THEIR
QUALITY," to be as follows:-
Whereas I have ascertained by a long series of researches and obser-
vations carried on in this country and in several wine producing districts
of Europe, and have by publications shown it to be the fact that sherry
and some other wines are regularly contaminated with sulphate of
potash and free sulphuric acid, and other impurities, which are added by
the wine makers either to the grapes, the must, or the made wine in
the shape of burnt or unburnt plaster of Paris or calcined earth
containing the same and the fumes of burnt sulphur, and in other
forms.

page_text: And whereas I have ascertained that by these proceedings the natural
acid of the must and wine, namely tartaric acid, is removed, and the
before-mentioned sulphuric acid substituted in its stead.
And whereas I have further ascertained that these impurities are pre-
judicial to the health of the consumers of such wine, as well as 5
diminishing the money value of such wine.
And whereas, further, I have by many and laborious researches and
experiments on a large scale carried on during a period of more than
4 years discovered a method by which these impurities, to wit, the
sulphate of potash and sulphuric acid and others may be completely 1
removed from the wine, and the tartaric acid originally contained
in or naturally belonging to good and proper wine may be restored
to it.
Now I declare the process by which these objects are attained to be as
follows:-I ascertain the amount of sulphuric acid contained in the
wine by chemical analysis in the manner well known in science; I then
add to the wine a quantity of tartrate of baryum in the state of a very
fine powder, or in the state of a freshly made precipitate, or I add to
the wine a quantity of tartaric acid first, and a quantity of hydrated
caustic baryta dissolved in a minimum of hot water afterwards, sufficient
in each case to precipitate nearly all the sulphuric acid and a portion of
the potash, and agitate the mixture. After the lapse of a few days I
rack, decant, filter, or otherwise separate the clear wine from the pre-
cipitate; I then allow the wine to repose in a cool place for some time
to enable it to deposit any surplus of tartar or bitartrate of potassium
which it may contain. When clear the wine is tested to prove that all
the impurities have been removed, and that not a trace of the agents
employed in this removal has remained in the wine, excepting alone a
small portion of tartaric acid.
And I declare the effect of my discovery and Invention to be that the
wine treated by my process is much improved in taste and flavour, that
its colour is riper, and that it matures much better than wine not so
treated, and that it has therefore a much greater money value than the
impure wine containing the said impurities.
And I further declare that by this method the ordinary processes of
fining wines by the blood of oxen and sheep, by whites of the cggs of

page_text: birds, or by cows' milk, or by Spanish carth, so called, or by isinglass
or gelatine, or by dextrine and sulphurous acid, or the fumes of sulphur
burnt, all of which, though fining the wine, leave some of their soluble
ingredients in the wine, and compromise its quality, are made unneces-
sary and superfluous.
And I further declare that by these my processes the wines treated by
them are made much more wholesome than they are in their ordinary
impure state, and that therefore my discovery and Invention will not
only be of advantage to persons using it for profit, but will be of public
utility.