IMPROVEMENTS IN THE MANUFACTURE OP OXALIC ACID
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN WILLIAM
NYREN, of Bromley, in the County of Middlesex, Manufacturing Chemist,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent, under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-sixth day of June, in the fourth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said John
William Nyren, Her especial licence, full power, sole privilege and authority,
that I, the said John William Nyren, my exors, adññiors, and assigns, or such
others as I, the said John William Nyren, my exors, adññors, or assigns,
should at any time agree with, and no others, from time to time and at
all times during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN THE MANUFACTURE
OP OXALIC ACID;" in which said Letters Patent is contained a proviso, that
I, the said John William Nyren, shall cause a particular description of the
nature of my Invention, and in what manner the same is to be performed,
to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John William Nyren, do hereby declare that the nature of my Invention,
and the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof (that is to say)
My Invention relates, first, to a mode of manufacturing oxalic acid, by the
application of a product obtained from potatoes; secondly, my Invention

page_text: relates to a mode of manufacturing oxalic acid by the application of a product
obtained from horse chesnuts; and, thirdly, my Invention relates to a mode
of manufacturing oxalic acid by means of leaden vessels.
And in order to give the best information in my power, I will proceed to
describe the processes as pursued by me in carrying out my Invention.
In manufacturing oxalic acid by the application of a product obtained from
potatoes, the potatoes are first to be well washed and then reduced into a
fine pulp by rasping, grinding, or otherwise; such pulp is then washed two or
three times, by placing it in water and well stirring it therein, then permitting
the pulp to subside and then running off the water; this washing process is
not absolutely necessary, but I find it desirable to remove impurities, which I
prefer should be done before submitting the pulp to the action of acid or
diastase, as hereafter explained, to obtain the product desired. The pulp thus
obtained I place in an open vessel; I prefer it to be of lead or lined with lead
where the pulp is to be submitted to the action of acid or disastase to obtain
the product, which is to be subsequently converted into oxalic acid. The pulp
of potatoes, either washed or not, as above explained, when in a vessel as above
stated (the shape of which is not material), is to have as much water applied
thereto as will allow of the same being boiled freely, and the vessel is to be
heated by leaden steam pipes or other convenient means, as is well understood
by persons acquainted with boiling liquids in vessels lined with lead. Into the
mixture of pulp and water, about two per cent. by weight (of the potatoes
employed) of sulphuric acid, usually called oil of vitriol of commerce, is to be
stirred, which will be at the rate of from eight to ten per cent. of acid to the
quantity of farina contained in such potatoes, and the whole are to be boiled
for some hours, till the farina contained in the pulp is converted into the state
desired, which will readily be ascertained by applying a drop of tincture of
iodine to a small quantity of boiling liquor on the surface of a piece of glass,
when, if there be any farina remaining unconverted, a purple color will be
produced; but if no unconverted farina remain, the color will be unchanged on
applying the tincture of iodine. The liquor thus obtained is then to be filtered;
I prefer passing it through horsehair cloth, by which a clear liquor will be
obtained, which is to be carefully evaporated in any convenient vessel, till it is
about fourteen or fourteen and a half pounds to the imperial gallon, and in
this state it is in a proper condition to be employed in the manufacture of
oxalic acid, by applying acid in the same manner as is at present practised
when using sugar, and which is well understood; and such liquor is to be
submitted to the action of heat in earthenware jars, as at present practised,
or in vessels of lead as herein-after described, till the saccharine matter is

page_text: decomposed; the liquor is then allowed to cool and crystallize, and the mother
waters drawn off and used with fresh liquors, as is well understood by oxalic
acid makers. It will therefore be seen that the liquor obtained from potatoes
as herein explained, according to the first part of my Invention, is used in place
of sugar, and the process subsequent to the application of nitric or nitros acid
with such product of potatoes, are similar to and are to be judged of in like
manner by the operator as when treating sugar and nitric or nitros acid for a
like purpose.
In carrying out the second part of my Invention, the only difference in the
treatment of the horse chesnuts is, that they do not require washing, but are
to have the outer shells skinned off; in other respects the description above
given applies to horse chesnuts in obtaining a product therefrom for the
manufacture of oxalic acid. I would remark that the farina of potatoes and of
horse chesnuts may be treated with diastase, and converted into a similar liquor
to that obtained after evaporation from the farina and sulphuric acid above
described, using about the same proportion of diastase as above directed for
sulphuric acid; in this case I make the liquor of the required strength at once,
and the processes of filtration and evaporation will be avoided in other respects.
The information above given will apply to this mode of obtaining the desired
product from the farina of potatoes and of horse chesnuts, but I prefer the
use of sulphuric acid for converting the farina, it being the cheapest.
I will now describe the third part of my Invention; in doing so, I would
first remark that in the manufacture of oxalic acid, earthenware jars or
vessels are employed when operating by heat on the liquors to be converted
into oxalic acid by the action of nitric or nitros acid, which jars or vessels are
necessarily very limited in dimensions, and consequently in manufacturing ou
a large scale the expence of using such jars is very considerable, and it is im-
portant to obtain larger vessels, and I have discovered that vessels of lead or lined
with lead may be employed when using nitric or nitros acid, and this allow of
large vessels being used in the manufacture of oxalic acid, by which considerable
advantages will be derived. I have found that square open vessels are
suitable for the process, and have used them of eight feet by eight feet and
three feet deep, and such I find to be convenient, but these dimensions as well
as the shape, may be varied. And I have constructed such vessels of wood,
and have lined them with lead, and in order to heat the liquor therein, I apply
a coil of lead pipe at the bottom and pass steam into the same, or I circulate
hot water therein, as is well understood in heating liquids by such means for
other purposes; and I have found that a coil of about forty-eight feet of inch
pipe in a vessel of the size above mentioned is suficient to keep the liquor in

page_text: such vessel to the required temperature.
I would however remark, that I do
not confine myself to such mode of keeping up the required heat to the liquor
under process, as other means may be resorted to. The liquor to be con-
verted into oxalic acid prepared as at present practised (or made by applying
the products of the first and second parts of the Invention) are to be put into
such vessels and heated till the required decomposition has been effected, as is
well understood. The liquor is then drawn off by a syphon or by a cock at
the bottom of the vessel into shallow leaden vessels to cool and crystallize, and
the mother waters are to be drawn off from the crystals and again used as
heretofore. I would remark, in respect to the first and second parts of my
Invention, that I lay no claim to the treating of farina of potatoes and horse
chesnuts with sulphuric acid or diastase separately, but only when applied in
the manufacture of oxalic acid.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that what I claim is,
First, the mode of manufacturing oxalic acid by the application of a product
obtained from the farina of potatoes and sulphuric acid or diastase as, above
described.
Secondly, the mode of manufacturing oxalic acid by the application of a
product obtained from horse chesnuts and sulphuric acid or diastase, as above
described.
And, thirdly, the mode of manufacturing oxalic acid by means of converting
proper liquors prepared with nitric or nitros acid in leaden vessels, as above
described.
In witness whereof, I, the said John William Nyren, have hereunto set
my hand and seal, this Twenty-fourth day of December, One thousand
eight hundred and forty.
J. W. (L.s.) NYREN.
AND BE IT REMEMBERED, that on the Twenty-fourth day of December,
in the year of our Lord 1840, the aforesaid John William Nyren came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
thing thorain contained and snacified in form

page_text: the Clerk of the Patents of England, pursuant to an Act passed in the
fifth and sixth year of the reign of His late Majesty King William the
Fourth, entitled "An Act to amend the Law touching Letters Patent for
Inventions."
I, the said JOHN WILLIAM NYREN, in my said Specification, did describe my
Invention to consist of three parts, and at the end of my said Specification
I claimed the same as follows:-" First, the mode of manufacturing oxalic acid
by the application of a product obtained from the farina of potatoes and
sulphuric acid or diastase, as above described; secondly, the mode of manu.
facturing oxalic acid by the application of a product obtained from horse
"chesnuts and sulphuric acid or diastase, as above described; and, thirdly,
"the mode of inanufacturing oxalic acid by means of converting proper
liquors, prepared with nitric or nitros acid, in leaden vessels, as above
"described." And since the inrolment of my said Specification I bave found
that the third part of my said Invention is of great value; and I have also
found that the first and second parts of my said Invention have not come into
such extensive use as to make it desirable to retain any claim thereto, for
which reason I wish to disclaim, and I do hereby disclaim, all parts of my
said Specification which describe and claim the first and second parts of my
said Invention.
In witness whereof, I, the said John William Nyren, have hereunto set
my hand and seal, this Thirtieth day of April, in the year of our
Lord One thousand eight hundred and fifty-one.
J. W. NYREN.
(L.S.)

page_text: To the Clerk of the Patents of England.
This is to certify, that the above-named John William Nyren has applied to
me for leave to enter with you the above-written Disclaimer of part of the
Specification of a certain Invention, for which Letters Patent were granted to
him under the Great Seal of Great Britain, dated at Westminster, June 26th,
1840, and to which a Specification was duly enrolled. And having considered
of the said application, and no objection having been made to the same, I
hereby grant leave to the said John William Nyren to file his said Disclaimer,
pursuant to the Statute passed in the fifth and sixth years of the reign of His
late Majesty King William the Fourth, entituled "An Act to amend the Law
touching Letters Patent for Inventions."
Lincoln's Inn, May 5th, 1851.
AND BE IT REMEMBERED, that on the Thirtieth day of April, in the
year of our Lord 1851, the aforesaid John William Nyren came before our
said Lady the Queen in Her Chancery, and acknowledged the Disclaimer
aforesaid, and all and every thing therein contained and specified, in form above
written. And also the Disclaimer aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Enrolled the Twenty-ninth day of May, in the year of our Lord One
thousand eight hundred and fifty-one.