IMPROVEMENTS IN THE MANUFACTURE OF A NEW CHEMICAL COMPOUND FOR THE TREATING OF HIDES, AND FOR OTHER PURPOSES
Year: 1877

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 TREATING OF HIDES, AND FOR OTHER PURPOSES."
communication from Friedrich Knapp, Doctor of Philosophy and Professor,
of Brunswick, in the Empire of Germany.
Sealed the 22nd September 1877, and dated the 7th July 1877.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office of
the Commissioners of Patents on the 7th July 1877.
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 TREATING OF HIDES,
AND FOR OTHER PURPOSES." A communication from Friedrich Knapp, Doctor of
Philosophy and Professor, of Brunswick, in the Empire of Germany.
The new chemical compound to which this Invention relates is an oxide salt of
iron, prepared in the following manner, that is to say:-To a boiling solution of
green vitriol (sulphate of iron) as much nitric acid is added as will thoroughly
oxidise the same; the effervescence being over, the operation is reversed, green
vitriol being added to the solution now containing iron oxide; the second ebullition
or effervescence caused by this operation having subsided, the compound has now
a somewhat syrupy nature, and is of a yellow red color; if it be slowly evaporated
there remains the dry iron oxide salt as an orange-red transparent varnish.
Basic sulphate of iron manufactured in this manner is very different in its physical
properties from that found in commerce, and described in chemical books. This
latter does not give a syrupy solution and is of a much darker color, a brown-yellow,
and decomposes on being boiled in a watery solution.
On the other hand, the preparation above described, and to which this Invention
relates, may be boiled in a solution of 30-40° Be without decomposing, and is in
reality copiously taken up by the skins of animals.

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 5th January
1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort-on-the-Maine, in 'the Empire of Germany. "IMPROVEMENTS IN THE
MANUFACTURE OF A NEW CHEMICAL COMPOUND FOR THE TREATING OF HIDES,
AND FOR OTHER PURPOSES." A communication from Friedrich Knapp, Doctor of
Philosophy and Professor, of Brunswick, in the Empire of Germany.
The new chemical compound to which this Invention relates is an oxy-salt of
iron, prepared in the following manner, that is to say:-To a boiling solution of
green vitriol (sulphate of iron) as much nitric acid is added as will thoroughly
oxidize the same; the effervescence being over, the operation is reversed, green
vitriol being added to the solution now containing iron oxide; the second ebullition
or effervescense caused by this operation having subsided, the compound has now a
somewhat syrupy nature, and is of a yellow-red colour; if it be slowly evaporated,
there remains the dry iron oxy-salt as an orange-red transparent varnish.
Basic sulphate of iron manufactured in this manner is very different in its physical
properties from that found in commerce and described in chemical books. The
latter does not give a syrupy solution and is of a much darker colour, a brown-yellow,
and decomposes on being boiled in a watery solution.
On the other hand, the preparation above described, and to which this Invention
relates, may be boiled in a solution of 30 to 40 degrees Baumé, without decomposing,
and is in reality copiously taken up by the skins of animals.
Having thus fully described the said Invention and the manner of performing
the same, I wish it understood that I claim,-
First. The oxy-salt basic sulphate of iron, prepared as and having the physical
properties above described.
Second. The process of preparing basic sulphate of iron by first adding nitric acid
to the boiling solution of sulphate of protoxide of iron, and subsequently adding to
the resulting solution sulphate of protoxide of iron, and either allowing the salt to
remain in solution or evaporating the same to dryness, as above set forth and for
the purpose specified.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand
and seal, this Thirty-first day of December, in the year of our Lord One
thousand eight hundred and seventy-seven.
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FRANK WIRTH. (L.S.)