Year: 1896

page_text: I EDWARD JOHN ADAMS Crow Tree House Sheffield in the County of York
Surgeon, do hereby declare the nature of this invention to be as follows:-
The application of a colorless fluid by means of which writing or
made therewith do not become legible until submitted to a certain simple
impressions
process.
The nature of the fluid used consists of sulphuric acid and water in the
proportion of one part of former to seventeen parts of latter (more or less) by means
of which writing thus made does not become visible until submitted to the heat
of a fire or other similar means of heat sufficient to cause carbonisation of the
superficial surface of the material written upon where written upon thus the words
appear in black letters without the paper upon which they have been written or
otherwise impressed being similarly affected. Thus in communications upon post-
cards private correspondence or other media the subject matter becomes only
legible to the party in possession of the particulars for developing the same.
The fluid being noninjurious also affords a safe and amusing novelty in its
various applications by the public.
Dated this 11th day of March 1896.
EDWARD JOHN ADAMS.
I EDWARD JOHN ADAMS, of Crow Tree House, Sheffield, in the County of
York, Surgeon, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention of a colorless ink, or writing fluid, for communications upon post-
cards, private corrrespondence, or other media; consists of the following
solution:-
Sulphuric acid and water in the proportion of one part of the former to seventeen
of the latter more or less.
By the application of this colorless ink, writing, or impressions made therewith,
do not become legible, until submitted to the following process. The writing, or
impression, is made with the above fluid, on writing paper, postcards, parchment, or
other suitable material, when to the observer the means of communication appears
blank, but if held before a fire, the writing or impression made thereon, appears in
legible permanent black: it may also be developed, by holding for a few moments
in a hot open oven, or by other means of applying heat, for the development of the
writing, or characters; by such or other means carbonization takes place upon the
surface of the paper where the characters or impressions are made.
LD

page_text: Thus in communications upon postcards, private correspondence, or other media,
the subject matter becomes only legible to the party in posession of the aforesaid
particulars for developing the same, and when developed in accordance with the
process above described, or any method of obtaining the necessary heat, the writing,
design, or communication, appears black.
My colorless ink or writing fluid being noninjurious, also affords a safe and
amusing novelty in its various applications by the public.
Having now particularly described, and ascertained the nature of my colorless
ink, or writing fluid, and in what manner, the same may be used and made visible,
I declare that what I claim is.
(1.) The application, and invention of a colorless ink, or writing fluid, by means of
which writing or impressions made therewith, do not become legible until submitted
to any of the above processes, as hereinbefore described.
(2.) That by means of this colorless ink, or writing fluid, communications upon post-
cards, private correspondence, or other media, may be made; the subject matter of
which only becomes legible to the person or persons in posession of the particulars
for developing the same as hereinbefore described.
(3.) That as this colorless ink, or writing fluid, is noninjurious, it also affords a
safe, and amusing novelty, in its various applications by the public, as hereinbefore
described.
Dated this 9th day of October 1896.
EDWARD JOHN ADAMS.