IMPROVEMENTS IN THE TREAT- MENT OF PYROXYLIN FOR PHARMACEUTICAL, PHOTOGRAPHIC, AND OTHER PUR- POSES
Year: 1877

page_text: $5
LETTERS PATENT to Ferdinand August Zimmermann, of 21, Mincing Lane,
in the City of London, for the Invention of IMPROVEMENTS IN THE TREAT-
MENT OF PYROXYLIN FOR PHARMACEUTICAL, PHOTOGRAPHIC, AND OTHER PUR-
POSES." A communication from abroad by Ernst Schering, of Berlin, in the
"
Empire of Germany.
Sealed the 12th April 1878, and dated the 15th December 1877.
PROVISIONAL SPECIFICATION left by the said Ferdinand August Zimmer-
mann at the Office of the Commissioners of Patents on the 15th December
1877.
FERDINAND AUGUST ZIMMERMANN, of 21, Mincing Lane, in the City of London.
"IMPROVEMENTS IN THE TREATMENT OF PYROXYLIN FOR PHARMACEUTICAL,
PHOTOGRAPHIC, AND OTHER PURPOSES." (A communication from abroad by Ernst
Schering, of Berlin, in the Empire of Germany.)
The preparation of a pure nitro-cellulose for photographic and medicinal collodium
has hitherto been accompanied with great difficulty, although this substance plays
a very important part, not only in photography, but in pharmacy also.
The collodium wool, also called pyroxylin, which has been manufactured up to
the present time, has always presented many inconveniences; it retains in it an
acid compound that cannot be removed by simple washing. But this acid com-
pound is extraordinarily troublesome and detrimental in the application of collodium
wool.
When the pyroxylin containing it is employed for photographic purposes, it
yields a red and useless collodium, and the collodium prepared from it for pharma-
ceutical purposes is irritant to wounds. This acid compound is separated by a new
and peculiar method, according to which the pyroxylin is treated for a considerable
time at a warm temperature with a dilute solution of potassium permanganate, then
with a very dilute solution of sulphurous acid, and finally washed well with distilled
water. This preparation is called celloidin, it being the purest nitro-cellulose; it

page_text: gives with pure ether and alcohol a collodium that does not become acid, and with
sensitive salts of iodine, such as ammonium iodide and sodium iodide, is coloured
only faintly yellowish and not brown.
Medicinal celloidin-collodium is prepared either direct from the celloidin by
dissolving it in a certain quantity of alcohol and ether (according as a one, two,
three, or four per cent. collodium is desired) or from the colloidin-gelatine¸ by
dissolving it in certain proportions of ether and alcohol.
Celloidin-collodium for photography is prepared in a similar way of the required
degree of concentration by the addition of pure alcohol and pure ether, as crude
photographic collodium. Also as a finished iodized negative collodium which is
remarkable in that it does not undergo change in the iodized condition, and is
therefore suitable for exportation.
Other ordinary collodium in the crude condition must be kept apart from the
iodizing material, and the latter must be transported separately.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ferdinand August Zimmermann in the Great Seal Patent Office
on the 15th June 1878.
FERDINAND AUGUST ZIMMERMANN, of 21, Mincing Lane, in the City of London.
"IMPROVEMENTS IN THE TREATMENT OF PYROXYLIN FOR PHARMACEUTICAL,
PHOTOGRAPHIC, AND OTHER PURPOSES. (A communication from abroad by Ernst
Schering, of Berlin, in the Empire of Germany.)
The preparation of a pure nitro-cellulose for photographic and medicinal collodium
has hitherto been accompanied with great difficulty, although this substance plays
a very important part, not only in photography, but in pharmacy also.
The collodium wool, also called pyroxylin, which has been manufactured up to
the present time, has always presented many inconveniences; it retains in it an
acid compound that cannot be removed by simple washing. But this acid com-
pound is extraordinarily troublesome and detrimental in the application of collodium
wool.
When the pyroxylin containing it is employed, it yields a red and useless collo-
dium, and the collodium prepared from it for pharmaceutical purposes is irritant
to wounds. This acid compound is separated by a new and peculiar method,
according to which the pyroxylin is treated for a considerable time at a warm
temperature with a dilute solution of potassium permanganate, then with a very
dilute solution of sulphurous acid, and finally washed well with distilled water.
The celloidin prepared as above described may be in liquid form or in a condensed
form, such as gelatine, in which state it is rendered inexplosive, more compact for
transport, and more convenient for the consumer, who can regulate the proportions
of collodium desired. This preparation is called "celloidin," it being the purest
nitro-cellulose. It gives with pure ether and alcohol a collodium that does not
become acid, and with sensitive salts of iodine, such as ammonium iodide and sodium
iodide, is coloured only faintly yellowish and not brown.

page_text: Medicinal Celloidin and Collodium.-This is prepared either direct from the
celloidin by dissolving it in a certain quantity of alcohol and ether (according as
a one, two, three, or four per cent. collodium is desired) or from the celloidin gelatine
by dissolving it in certain proportions of ether and alcohol.
Celloidin Collodium for Photography. This is prepared with celloidin, according
to the degree of concentration required, by the addition of pure alcohol and pure
ether, similarly to the preparation of crude photographic collodium.
Also as a
finished iodized negative collodium, which is remarkable in that it does not undergo
change in the iodized condition, and is therefore suitable for exportation.
Other ordinary collodium in the crude condition must be kept apart from the
iodizing material, and the latter must be transported separately.
Having now described the nature of the said Invention and in what manner the
same is to be performed, I declare that I claim the treatment of pyroxylin in the
manner described, whereby the substance herein called "celloidin" is prepared.
In witness whereof, I, the said Ferdinand August Zimmermann, have here-
unto set my hand and seal, this Fourteenth day of June, One thousand
eight hundred and seventy-eight.
F. A. ZIMMERMANN. (L.S.)