IMPROVEMENTS IN THE PREPARATION OF SAFETY PAPER
Year: 1868

page_text: LETTERS PATENT to John Jameson, of No. 10, Catherine Terrace,
Gateshead, in the County of Durham, Engineer, for the Invention
of "IMPROVEMENTS IN THE PREPARATION OF SAFETY PAPER."
Sealed the 18th September 1868, and dated the 25th March 1868.
PROVISIONAL SPECIFICATION left by the said John Jameson at
the Office of the Commissioners of Patents, with his Petition, on
the 25th March 1868.
I, JOHN JAMESON, of No. 10, Catherine Terrace, Gateshead, in the
County of Durham, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE PREPARATION OF SAFETY PAPER," to
be as follows:-
I print on the paper a design or designs of such character as that by the
use of chemical inks the design shall either be changed in color or
obliterated, or being invisible or nearly so shall be rendered visible at
the parts written upon; or I prepare a paper answering to more than
one of these tests, selecting the chemicals, and so applying the designs as
to make alterations of the writing or imitation of the chemical action
very difficult if not impossible.

page_text: As an instance of change of color the design may be printed with a
colored persalt of iron and the writing effected with a ferrocyanide.
As an instance of obliteration the design may be printed with Prussian
blue and the writing made with an alkali.
As an instance of developement of invisible or nearly invisible design
the printing may be done with a ferrocyanide and the writing with a
persalt of iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Jameson in the Great Seal Patent Office on
the 25th September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
JAMESON, of No. 10, Catherine Terrace, Gateshead, in the County of
Durham, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of March, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Jameson, Her special licence that I,
the said John Jameson, my executors, administrators, and assigns,
or such others as I, the said John Jameson, my executors, adminis-
trators, 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 "IMPROVEMENTS IN THE
PREPARATION OF SAFETY PAPER," upon the condition (amongst others) that
I, the said John Jameson, 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 John Jameson, do hereby declare
the nature of the said Invention, and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and. by
the following statement thereof, that is to say :-
I print on the paper a design or designs of such character as that
by the use of chemical inks the design shall either be changed in color
or obliterated, or being invisible or nearly so shall be rendered visible
at the parts written upon; or I prepare a paper answering to more
than one of these tests, selecting the chemicals and so applying the
designs as to make alterations of the writing or imitation of the chemical
action very difficult, if not impossible.
As an instance of change of color the design may be printed with
a colored persalt of iron and the writing effected with a ferrocyanide.
As an instance of obliteration the design may be printed with Prussian
blue, and the writing made with an alkali.
As
an instance of developement of invisible or nearly invisible
design the printing may be done with a ferrocyanide and the writing
with a persalt of iron.
Having thus stated the nature of the Invention I will proceed
more particularly to describe the manner of carrying the same into
effect.
A great variety of chemical substances are available for the purpose
of carrying out my Invention, and the chemicals or combination of
chemicals may require to be varied so as to suit the particular cir-
cumstances in which the paper is intended to be used.
The preparation which I prefer to employ for ordinary purposes
is
the following:-If the paper contain traces of iron or other injurious'
matter I film it with a thin film of such material as gutta percha
dissolved in chloroform or other suitable solvent, so as to some extent
to insulate the chemical design from impurities in the paper. I then
print from an engraved block a design of minute wavy lines having
very small intervals between each (about 60 to the inch is a fair
proportion) in an ink composed of gum arabic in water or gelatine,
albumen, or other medium suitable for giving tenacity to the ink with
ferrocyanide of potassium. After this design has become dry I print
over it a second much more open design (which I call for distinction
the super design) crossing the first in an ink composed of gum arabic
or other suitable medium in water, to which a very small quantity of
perchloride of iron has been added so as to produce this last design
in a just perceptible blue color at its points of intersection with the.

page_text: first design or otherwise. I give to the primary design a slight blue
color by admixture of a very minute portion of the permuriate of iron
with the ink of which it is composed. I use with the paper so
prepared an ink composed of a weak solution of perchloride of iron
and gum, and the writing is produced in Prussian blue by the inter-
section of the lines formed by the pen and the lines formed by the
first printed design. If it be desired to render the writing still more
secure than by the process I have described I employ for the design
an engraved block of wavy lines (as before described) with spaces
between the lines of such a size as to enable me to print another line 1
between each line of the design, say, for instance, 30 lines to the inch;
and in the spaces thus left I print a similar design in infusion of
galls with a little gum, and having impressed the super design as
before, I use the same chemical ink, which developes at the points
of intersection with the designs first mentioned alternate spots of black 1
and blue.
The object of my Invention is to indicate the genuine character of
the ink employed, and I accomplish it in the manner I have stated by
furnishing in the paper itself the necessary chemical tests.
There exist already many processes for detecting the extraction of 2
genuine writing ink from paper by chemical agents which may be used
in combination with my process or not. If it be desired to avoid the
necessity for using a special ink the design in a persalt of iron may
be printed on the paper, and a thin film of gutta percha thereafter
applied; and after the whole has become thoroughly dry ferrocyanide
of potassium in the form of an impalpable powder suspended in alcohol
with a little Canada balsam or gum damma may be applied spread
over the surface. If a writing be made on this paper by means of
water only or water and gum it will develope the design at the points
of intersection; or the same effect may be produced by printing a
design in ordinary ink, and soaking the paper with oxalic acid in
absolute alcohol; and when the oxalic acid is brought into contact
with the design by means of water discharge of color will take place;
but the disadvantage of these processes is that long exposure to damp
or wetting will destroy the properties of the paper.
Another manner in which my process may be employed is with
ordinary ink, in which case I prefer to employ at least two designs of
a more bold character than those I have before described, say 15 lines

page_text: to the inch, one being in such chemicals as oxalic or meconic acid,
and one in such as carbonate of soda or bichromate of potash. The
design in oxalic acid is developed under the covering of most inks by
discharge of the black color from the same, and the design on the
soda is developed by the deposit of a black precipitate passing gradually
into a brown by exposure to air or over the bichromate of potash
into an instantaneous and tolerably permanent black; but I prefer to
employ special inks not requiring this change of color in all cases in
which they can be conveniently used.
Another method in which paper may be prepared for ordinary inks
is by printing as before directed with ferrocyanide of potassium and
soaking the paper when quite dry with solution of oxalic acid in
alcohol.
Having thus stated the nature of my Invention, and the manner in
which the same is to be performed, I would have it understood that I
do not confine myself to the chemicals which I have named; but
what I claim as my Invention is, the production of a design or
designs in such manner as to indicate by discharge, change, or
developement of color the character of the ink employed substantially
as I have described.
In witness whereof, I, the said John Jameson, have hereunto
set my hand and seal, this Seventeenth day of September, in
the year of our Lord One thousand eight hundred and sixty-
eight.