AN IMPROVED METHOD OF MANUFACTURING CHLORINE
Year: 1867

page_text: LETTERS PATENT to Walter Weldon, of Park Villa, West Hill, High-
gate, in the County of Middlesex, for the Invention of "AN IMPROVED
METHOD OF MANUFACTURING CHLORINE."
Sealed the 9th July 1867, and dated the 18th January 1867.
PROVISIONAL SPECIFICATION left by the said Walter Weldon at the
Office of the Commissioners of Patents, with his Petition, on the
18th January 1867.
I, WALTER WELDON, of Park Villa, West Hill, Highgate, in the County
of Middlesex, do hereby declare the nature of the said Invention for "AN
IMPROVED METHOD OF MANUFACTURING CHLORINE," to be as follows:-
In order to the manufacture of chlorine by the new method which
constitutes my present Invention I first prepare tersulphate of sesquioxide
of iron by treating the said sesquioxide with somewhat more than three
equivalents of sulphuric acid, and then heating the product till the excess of
acid is driven off; I then mix the tersulphate of sesquioxide of iron so
produced with three equivalents (being one for each equivalent of sulphuric
acid in the tersulphate) of either chloride of sodium or other suitable chloride,
and thereby obtain a mixture which readily evolves chlorine when heated in a
current of dry air. As this mixture when thus heated in a current of air
evolves in the free state, the whole of the chlorine contained in the chlorido

page_text: of sodium or other metal which forms one of its ingredients, whereas by the
system of manufacture hitherto practised scarcely more than one-fifth of the
chlorine in the chloride of sodium which yields the bydrochloric acid employed
in that manufacture is ever obtained in the free state, and as the chlorine
evolved from the mixture in question is moreover obtained without any
expense whatever for oxide of manganese, which oxide is one of the essential
agents of the chlorine manufacture as at present conducted, and at present
usually costs the manufacturer more than all his other materials put together,
I believe that the manufacturers of bleaching powder and other compounds
for the production of which free chlorine is required will find very great
advantages in obtaining their chlorine by the method constituting my present
Invention, instead of by the method at present in use. At the same time I
believe that the facility with which the mixture above described evolves
chlorine, when heated as directed, will tend to render unnecessary much of
the present production of bleaching powder, inasmuch as large consumers of
that compound for bleaching purposes will find a great advantage in buying,
instead of bleaching powder, or in making for themselves the said mixture
of tersulphate of sesquioxide of iron and chloride of sodium or other metal,
and then producing from it their own chlorine on the spot where the chlorine
is to be used. The chlorine so produced they need not combine with dry
lime so as to form bleaching powder, the better plan for them being to pass
it directly into either water alone or water admixed with some suitable oxide
or other body, so that it may form at once a liquid bleaching compound. A
valuable advantage of the mixture thus to be used for producing chlorine is
that it does not spoil by keeping, and transport to a warm climate, as
bleaching powder is so very apt to do.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Walter Weldon in the Great Seal Patent Office on the
11th July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
WELDON, of Park Villa, West Hill, Highgate, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of January, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirtieth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto

page_text: me, the said Walter Weldon, Her special licence that I, the said Walter
Weldon, my executors, administrators, and assigns, or such others as I, the
said Walter Weldon, my 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 "AN
IMPROVED METHOD OF MANUFACTURING CHLORINE," upon the condition (amongst
others) that I, the said, Walter Weldon, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and 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 Walter Weldon, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement :-
In order to manufacture chlorine by the new method or process which
constitutes my present Invention I first prepare tersulphate of sesquioxide of
iron, which compound may be represented either as Fe³ 0%, 3 SO³, or as Fe²
(SO), by treating an equivalent of sesquioxide of iron with a little more
than three equivalents of sulphuric acid, and then driving off the excess of
acid by means of a heat just sufficient to expel such excess without decom-
posing the tersulphate itself; I then mix the anhydrous tersulphate so
produced with three equivalents of chloride of sodium or other suitable
chloride, being one equivalent of chloride for each equivalent of sulphuric acid
in the tersulphate, and I thereby obtain a mixture which will give off one-
tbird of the chlorine contained in it on being simply heated without access of
air, and which, under the influence of heat and a current of air combined,
will give off the whole of the chlorine contained in it. In order to prevent
the formation of hydrochloric acid, which if formed would contaminate the
chlorine, the chloride used must be thoroughly dried before being mixed with
the tersulphate; both the tersulphate itself and the mixture of tersulphate
and chloride must be constantly so protected as to have no opportunity of
absorbing atmospheric or other moisture; and the current of air passed into
the vessel in which the mixture of tersulphate and chloride is heated should
first be deprived of moisture by any of the various simple methods well known
to chemists.

page_text: Having thus particularly described and ascertained the nature of my said
Invention, and the manner in which the same is to be performed, I claim as
new and original, and desire to have secured to me by the herein-before in part
recited Letters Patent, the nianufacture of chlorine by means of a mixture of
tersulphate of sesquioxide of iron and a suitable metallic chloride, substantially
as is above described.
In witness whereof, I, the said Walter Weldon, have hereunto set my
hand and seal, this Tenth day of July, in the year of our Lord
One thousand eight hundred and sixty-seven.
WALTER WELDON. (L.S.)