IMPROVE- MENTS IN PHOTOGRAPHY
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
HENRY FOX TALBOT, of Lacock Abbey, in the County of Wilts, Esquire
and THOMAS AUGUSTINE MALONE, of Regent Street, in the County of Middle-
sex, Photographer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Nineteenth day of
December (One thousand eight hundred and forty-nine), in the thirteenth year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said William Henry Fox Talbot, and Thomas Augustine Malone,
our exors, admors, and assigns, Her especial licence, full power, sole privilege
and authority, that we, the said William Henry Fox Talbot, and Thomas
Augustine Malone, our exors, admors, and assigns, or such others, as we,
the said William Henry Fox Talbot, and Thomas Augustine Malone, our
exors, admors, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, our Invention of "IMPROVE-
MENTS IN PHOTOGRAPHY;" in which 'said Letters Patent is contained a pro-
viso, that we, the said William Henry Fox Talbot, and Thomas Augustine
Malone, or one of us, shall cause a particular description of the nature of our
said Invention, and in what manner the same is to be performed, by 'an instru-

page_text: ment in writing under our hands and seals, or under the hand and seal of one
of us, to be inrolled in Her Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.
, NOW KNOW YE, that in compliance with the said proviso, we, the said
William Henry Fox Talbot, and Thomas Augustine Malone, do hereby declare
the nature of our said Invention, and the manner in which the same is to be
performed, are fully described and ascertained in and by the following state-
ment thereof, that is to say:-
The first part of the Invention consists in the use of plates of unglazed
porcelain to receive the photographic images. A plate, intended for photo-
graphic purposes, should be made of the finest materials used by porcelain
manufacturers. It should be flat, very thin, and semi-transparent. If too
thin to be used, without risk of breaking, it should be cemented on one side to
a plate of glass to strengthen it. It should be very uniform in substance, and
close grained. The substance of the plate should be slightly porous to enable
it to imbibe and retain a sufficient quantity of the chemical liquids employed.
To prepare the plate for use, it is first requisite to give it a coating of white of
egg laid on very evenly, and then gently dried at a fire. According as the
plate is more or less porous, it requires more or less of this previous coating.
It is best to employ a very close grained porcelain, which requires very little of
the white of egg. The plate being thus prepared, it may be rendered sensi-
tive to light, in the same way in which a sheet of paper is rendered sensitive.
For we find that, speaking generally, the same methods which we have hitherto
adopted in making photographic pictures upon paper can be equally well
employed upon these porcelain plates, so that it will be sufficient to describe
one of these methods, being nearly the same that was originally employed for
the calotype, since called the Talbotype process upon paper, as described in
the Specification of the Patent granted to William Henry Fox Talbot, in the
year One thousand eight hundred and forty-one. The prepared porcelain
plate is dipped into a solution of nitrate of silver, containing twenty-five
grains of the nitrate to one ounce of water; or else this solution is spread over
it uniformly with a brush. The plate is then dried, and then dipped into a
solution of iodide of potassium, containing twenty-five grains of the salt to
one ounce of water. It is then again dried and its surface rubbed clear and
smooth with a bit of cotton. The plate is now of a pale yellow colour, due to
the presence of iodide of silver, and it is to be kept in this state until wanted
for use.
When employed, it is to be excited or rendered sensitive to light, by
1

page_text: washing it over with a solution of gallo-nitrate of silver, and then placed in the
camera, and the image obtained is to be rendered visible and sufficiently
strengthened by another wash of the same liquid, aided by gentle warmth. The
negative picture, thus obtained, is fixed by washing it with water, then with
bromide of potassium, or better with hyposulphite of soda, and again several.
times with water. The process and manipulation do not differ from that.
described, as applicable to photography on paper, in the Specification of the
above-mentioned Patent of One thousand eight hundred and forty-one. The
plates of porcelain being semi-transparent, positive pictures can be obtained
from the above-mentioned negative ones, by copying them in a copying frame.
The pictures obtained on plates of porcelain can be further altered or modified
in appearance by the subsequent application of a strong heat, differing much
in that respect from those obtained upon paper. With respect to this part of
our Invention, we claim the obtaining by means of a camera, or by means of
a copying frame, photographic images or pictures upon slabs or plates of
porcelain.
The next part of the Invention is a method of converting or changing
negative photographic images into positive ones, which is performed as
follows:-Albumen or white of egg is diluted with water, and then filtered
through linen cloth; this solution is poured on a clean plate of glass, and
then allowed to flow off slowly: the glass is then gently warmed until the
albumen is dried into a very uniform, transparent and almost invisible film;
the glass is then placed horizontally upon the top of a vessel containing
iodine, with the film of albumen downward, and raised about three or four.
inches above the iodine, where it remains until the film acquires a yellow tinge,
which occurs in a few minutes. The plate is then dipped into a vessel contain-
ing a solution of nitrate of silver, of about fifteen grains to one ounce of
water; it is withdrawn, and the superfluous liquid allowed to drain off. It is
then placed in the camera to receive the photographic image; it is then
withdrawn and laid flat in a vessel, and a saturated solution of gallic
acid in water is poured over it to develope and render visible the
latent image or picture. In this process, so far as we have yet described
it, the only point which we believe to be new and first described by us,
is the iodising the film of albumen by exposing it to the vapour of iodine,
which may be advantageously mixed with a small portion of bromine;
but the remainder of the process now to be described we believe to be
a new Invention. The gallic acid being poured off from the plate, a solution
of nitrate of silver of about thirty grains to ounce of water is poured on
the plate, and after standing some time it effects a very remarkable change

page_text: upon the picture by converting the lights of the picture into shades, and vice
versâ, or in other words, it changes the picture from a negative to a positive
one. It must be observed, however, that the picture still appears negative
if viewed by transmitted light,. the positive appearance occurs only when
it is viewed by reflected light. It is a remarkable circumstance that a
great number of details and small minutiae of the picture are frequently
seen in the positive image, which disappear from their faintness when the
same picture is viewed by transmitted light, so as to appear negative. In
order that the positive image may be well seen, it is essential that the
glass should be placed upon a dark surface. It will be understood, of
course, that when the positive image has appeared, and sufficiently developed
itself, it must be fixed as usual by washing it with water, then with hypo-
sulphite of soda, and finally again with water. The same process may be
performed upon any regularly transparent surface, which admits of being
coated with a uniform coating of albumen, as tale, varnished paper, oiled
paper, &c., always placing a dark surface beneath the resulting picture to
enhance the effect. The same process may be also performed upon porcelain
of a black or dark colour, and upon other black or dark colored surfaces.
In this process we do not confine ourselves to the use of albumen, but occa-
sionally use gelatine and other animal and vegetable substances capable of
giving transparent films; but we believe albumen to be the most convenient.
With respect to this part of our Invention, we claim as new the conversion
of negative photographic images formed upon films of albumen, gelatine, or
other substances of animal or vegetable origin, into positive ones.
And, also, we claim as new the exposing such films, as aforesaid, to the
vapours of iodine and bromine as a preliminary to the formation of photo-
graphic images upon them, the employment of those vapours in photography
having been hitherto, as we believe, confined to their action on polished
metallic surfaces.
Our next improvement consists in the use of varnished paper, or other
transparent paper impervious to water, as a substitute for glass in certain cir-
cumstances, to support a film of albumen for photographic purposes. A sheet
of writing paper is brushed over with several coats of varnish on each side.
It thus becomes extremely transparent. It is then brushed over on one side
with albumen or a mixture of albumen and gelatine, and then dried. This
film of albumen is capable of being rendered sensitive to light by exposing it
to the vapour of iodine, and by following the rest of the process indicated in the
preceding section of this Specification. The advantages of using varnished or
oiled paper does not consist in any superiority of the images over those obtained

page_text: upon glass, but in the greater convenience of using paper than glass in cases
where a large number of. pictures have to be made and preserved, and carried
about for considerable distances. And, moreover, there is a well-known kind
of photographic pictures giving panoramic views of scenery, which are produced
upon a curved surface by a movement of the object glass of the camera. To
the production of these images glass is hardly applicable, since it cannot
readily be bent into the required curve and again strengthened; but the case
is met by employing as a substitute for glass, talc, varnished paper, or oiled
paper. It will be understood that the varnished paper acts only as a support
to the film of albumen or gelatine, which is the surface upon which the light
actually forms the picture.
The next improvement is a method of obtaining more complete fixation of
photographic pictures upon paper. For this purpose the picture, after under-
going the usual fixing process, is dipped into a boiling solution of strong
caustic potash, which changes the tint of the picture, and usually after a
certain time induces something of a greenish tint, which we consider a sign
that the process is terminated. The picture is then well washed and dried,
and if the tint acquired by it is not pleasing to the eye, a short exposure of it
to the vapours of sulphuretted hydrogen restores an agreeable brown or sepia
tint. The pictures exposed to this process with caustic potash shrink sensibly
in diameter, so that if a picture is cut in two, and one half of it only is treated
by this process, the two halves afterwards no longer correspond.
The next improvement consists in forming photographic pictures or images
upon the surface of polished steel plates. One part, by measure, of a satu-
rated solution of iodide of potassum is mixed with twenty parts of albumen,
and spread as uniformly as possible upon the surface of a steel plate, and then
dried by the gentle heat of a fire. The plate is then taken, and while still
warm, is washed over with an alcoholic solution of gallo-nitrate of silver of
moderate strength. It then becomes very sensitive, and easily receives a pho-
tographic image. If the plate is cold the sensibility is considerably lower.
The image obtained is fixed by washing with hyposulphite of soda, and finally
The picture adheres to the steel with much tenacity, and forms
a process useful to engravers.
with water.
With respect to this part of our Invention, our claim is for the production
of a photographic image upon a plate of steel.
In witness whereof, I, the said William Henry Fox Talbot, have here-
unto set my hand and seal, this Eighteenth day of June, in the
of our Lord Oue thousand eight hundred and fifty.
year
W. H. F. (L.s.) TALBOT.

page_text: AND BE IT REMEMBERED, that on the Eighteenth day of June, in the
year of our Lord 1850, the aforesaid William Henry Fox Talbot came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Nineteenth day of June, in the year of our Lord One
thousand eight hundred and fifty.

page_text: '
In the Matter of Letters Patent granted to WILLIAM HENRY Fox
TALBOT, of Lacock Abbey, in the County of Wilts, Esquire, and
THOMAS AUGUSTINE MALONE, of Regent Street, in the County of
Middlesex, Photographer, for their Invention of "IMPROVEMENTS IN
PHOTOGRAPHY,"
"and which said Letters Patent bear date at West-
minster the Nineteenth day of December, One thousand eight hun-
dred and forty-nine, to which a Specification was duly inrolled on
the Nineteenth day of June, One thousand eight hundred and fifty.
CLAIMER of the said William Henry Fox Talbot, in his own right, and
also as assignee of all that the undivided part or share of the above-
named Thomas Augustine Malone, of and in the above-named Letters
Patent, under and by virtue of a certain indenture bearing date the
Fifteenth day of December, One thousand eight hundred and fifty, and
made between the said Thomas Augustine Malone of the one part, and
the said William Henry Fox Talbot of the other part, whereby the said
Thomas Augustine Malone departed with the whole of his interest by
assignment to the said William Henry Fox Talbot, which Disclaimer is
proposed to be filed in the office for Specifications in Chancery by the
said William Henry Fox Talbot, pursuant to the provisions of the
Statutes in that behalf, that is to say:-.
I, the said William Henry Fox Talbot, do hereby disclaim the following
t of the said Specification, that is to say:-
First, the part thereof commencing with the words "the first part of the
ention consists in the use of plates of unglazed porcelain to receive the
tographic images," and extending from those words and including the same
tinuously to the end of the said first part of the Invention, down to and
luding the words "we claim the obtaining by means of a camera, or by
ans of a copying frame, photographic images or pictures upon slabs or
tes of porcelain.
Secondly, to omit the four next immediately following words, that is to
the words "the next part of."
,
Thirdly, to omit the words contained in the sentence shortly afterwards,
nmencing with the words "the same process may be performed upon any

page_text: "regularly transparent surface which admits," and extending from those words
continuously down to and including the words "black or dark coloured
surfaces."
Fourthly, to omit the three words in the claim next following, that is to
say, the words "part of our" immediately following the words "with respect
to this," and to add and insert the six following words in the same claim
immediately after the words "animal or vegetable origin," that is to say,
"adhering to the surface of glass."
'Fifthly, to omit the words in the said claim beginning with "the employ-
ment of those vapours," and extending from those words and including the
same continuously to the end of the same sentence.
Sixthly, to omit all the rest of the said Specification, beginning with the
words "our next improvement," and extending from those words and including
the same continuously to the end of the said Specification.
My reasons for such Disclaimer are, that the parts firstly, thirdly, fifthly,
and sixthly so disclaimed, are matters more of philosophical experiment and
curiosity than of practical utility, and I am advised that in any action brought
for an infringement of the said Letters Patent, objections may be raised which
would require evidence to be adduced in support respectively of those parts of
the said Invention which I now disclaim, thereby adding to the expense and
difficulty of such action; therefore, although I still fully believe that I
together with the said Thomas Augustine Malone, were the first and true
inventors of the said parts of the said Invention so intended to be disclaimed,
yet I consider it advisable to disclaim them, as aforesaid, and as to the words
secondly and fourthly so disclaimed, and the proposed addition of the six ?
words, viz, "adhering to the surface of glass," because the words so dis-
claimed are now superfluous, and the six words, proposed to be added as
aforesaid, are more fully descriptive of this part of the Invention intended to
be claimed.
In witness whereof, I, the said William Henry Fox Talbot, have here- 8
unto set my hand and seal, this Twenty-sixth day of March, in the
year of our Lord One thousand eight hundred and fifty-five.

page_text: Regent Street, in the County of Middlesex, Photographer, under the Great
Seal dated the 19th day of December 1849, the Specification to which was duly
enrolled, and the said Thomas Augustine Malone has assigned all his interest
in the said Patent to the said William Henry Fox Talbot; and on considering
the said application, I directed him to advertise his said Disclaimer in the Lon-
don Gazette, the Times, Morning Herald, and Morning Chronicle newspapers,
and such advertisements have been duly made, and no objection having been
made, I have accordingly granted leave to the said William Henry Fox
Talbot to file his said Disclaimer pursuant to the Statute 5th & 6th Will
4th, cap. 88, and 7 & 8 Victoria, c. 69.
AND BE IT REMEMBERED, that on the Twenty-sixth day of March, in
the year of our Lord 1855, the aforesaid William Henry Fox Talbot came
before our said Lady the Queen in Her Chancery, and acknowledged the
Disclaimer aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Disclaimer aforesaid was stamped accord-
ing to the tenor of the Statute made for that purpose.