IMPROVEMENTS IN THE MANUFACTURE OF A NEW CHEMICAL COMPOUND FOR THE TREATMENT OF HIDES AND THE LIKE PURPOSES
Year: 1879

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company, Patent
Solicitors, at Frankfort on the Main, in the Empire of Germany, for the
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF A NEW CHEMICAL
COMPOUND FOR THE TREATMENT OF HIDES AND THE LIKE PURPOSES." A
communication from Friedrich Knapp, Doctor of Philosophy and Professor, of
Brunswick, in the Empire of Germany.
Sealed the 14th May 1880, and dated the 29th November 1879.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 29th November 1879.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany. "IMPROVEMENTS IN THE
MANUFACTURE OF A NEW CHEMICAL COMPOUND FOR the TreatmenT OF HIDES
AND THE LIKE PURPOSES." (A. communication from Friedrich Knapp, Doctor of
Philosophy and Professor, of Brunswick, in the Empire of Germany.]
This Invention has for its object further improvements in the manufacture of
solutions of iron for the purposes indicated in the Specification of former Letters
Patent granted to me the 7th day of July 1877, No. 2624.
According to my present Invention I produce a solution of sulphate of peroxide
of iron, which acts in the same manner as the solution deseribed in the said former
Specification, but with better effect in tanning, moreover it is chemically a different
compound. This improved solution I produce by adding equivalent quantities of
sulphuric acid and nitrate of soda (nitre) instead of nitric acid to the boiling
solution of sulphate of protoxide of iron. With the exception of these substitutions
this solution is to be treated in the same manner as described in my said former
Specification.
The solution made according to my present Invention differs chiefly from the
former one by the soda of the nitre which enters into the new compound as a
constituent part along with the peroxide of iron and the sulphuric acid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frank Wirth in the Great Seal Patent Office on the 28th May
1880.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort-on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN THE
MANUFACTURE OF A NEW CHEMICAL COMPOUND FOR THE TREATMENT OF HIDES
AND THE LIKE PURPOSES." A communication from Friedrich Knapp, Doctor of
Philosophy and Professor, of Brunswick, in the Empire of Germany.
This Invention has for its object further improvements in the manufacture of
solutions of iron for the purposes indicated in the Specification of former Letters
Patent granted to me the 7th day of July 1877, No. 2624.
According to the present Invention I produce a new and improved solution of
sulphate of peroxide of iron, which acts similary to the solution described in the said
former Specification, but with better effect in tanning. Instead however of
employing nitric acid, which, according to the said former Specification, was
added to a boiling solution of sulphate of protoxide of iron, I add to a solution of
Sulphate of protoxide of iron equivalent parts of sulphuric acid and nitrate of soda
(nitre.) In other respects the solution of iron is prepared as set forth in the
Specification of the said former Letters Patent, that is to say, to the boiling
solution of sulphate of protoxide of iron as much sulphuric acid and nitrate of soda
are added as will thoroughly oxidize the same; when the effervescence is completed
the operation is reversed, sulphate of protoxide of iron being added to the solution
then containing iron oxide. The solution thus prepared is chemically quite
different from that referred to in the said former Specification, and differs princi-
pally from the latter for the reason that the soda of the nitre enters into the new
compound as a constituent part along with the peroxide of iron and the sulphuric
acid.
Having thus fully described the said Invention, and the manner of performing
the same, I wish it understood that I claim,—
First. The new chemical compound for tanning consisting of peroxide of iron,
soda, and sulphuric acid, as above set forth.
Second. The process of preparing the said chemical compound by adding to a boiling
solution of sulphate of protoxide of iron, firstly, a mixture of nitre and sulphuric
acid, and secondly, sulphate of protoxide of iron, in the manner above set forth.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand
and seal, this Twenty first day of May, in the year of our Lord One thousand
eight hundred and eighty.