Clause 3 and
clause 4 of the treaty between Niépce and
physico-chemical principle of the invention.
"I designate under the name of
Héliographie the discovery that is the
subject of this book. It is due to the observation of a phenomenon of
property, (..) which in its remarkable effects
is the solution that I proposed and
which now fix my
attention." (Nicéphore Niepce
Following the proposal of Daguerre
to use silver iodide as a light-sensitive layer:
"So after a few more attempts, I remained there,
although regretting deeply, I confess, to have
gone wrong for so long, and what is worse, if unnecessarily &&"
"But, I repeat, Sir, I do
not see that we can boast to take advantage of
this method, nor of those who hold to the use of metallic oxides ..."
Niépce to Daguerre: letters dated 8 November
1831 and 3 March 1832.
These comments Nicéphore confirm
The result suggested
and procedures recommended by Daguerre in August 1827.
Daguerre's advice was
so great that the Niépce mention in all correspondence
"When the mode of
application in metal engraving, it is far from depreciating, but as
it would be necessary to edit and dig with the chisel, he believes
that this application does not succeed very imperfectly for the
views, what seems much better for this kind of burning, the glass
using hydrofluoric acid (vapors), he is convinced that the printing
ink applied carefully to the surface corroded by acid, produce on
white paper, the effect of a good test, and would again, something
that would appeal to original advantage. &&& "
"and I hope to give
based representations of objects of silver plated, all gradations of
color from black to white, important thing that was well recommended
to me by Mr Daguerre ..." Niépce Curley November 28,
Following the advice of
Daguerre, Niépce wrote in 1829:
"The discovery that
I made and I refer to as Heliography
is to reproduce
spontaneously by the action of light, with the gradation from black
the image received
in the camera.
Summary: We'll specify the basis of the contract
between Niépce and Daguerre and give a reminder of the
articles restricting the enforcement of the contract. We'll insist on
the physico-chemical principle of the discovery of heliography and
give precise details about the names of the different processes.
We'll prove too that the process using the residue of the Essence of
Lavanda isn't the "Physautotype" , but the physiotipe.
"...hoping that I won't ask in vain the support of so
many people more able than I to ensure its success..."
"...bound by the agreement which stipulates that my
invention will only be made public when the required perfection has
been attained, this job will be the special charge of my
(from Niépce to de Curley : on the 18th of
"In 1829 Mr. Daguerre entered into partnership with
Mr.Niépce in order to perfect Mr.Niépce's process."
This discovery consists of the spontaneous reproduction
of images obtained in the camera obscura.
Art.3: ...Mr.Niépce will confide to
Mr.Daguerre... the principle on which is based
Art.4: ...Mr.Daguerre commits himself... to keep
silent, as much about the fundamental principle
of the discovery as... and to cooperate as much as he can on
doing the required improvements.
What I discovered and named "heliography" consists in
spontaneously bringing out the sunlit images received by the camera
obscura, and this with all the shading off black into white.
Basic principle of the
"Light chemically acts on the bodies either in its
composed or decomposed state. Light is absorbed, combines with these
elements and transmits them new properties. Thus, increasing the natural consistency of some of
these bodies, it even solidifies them and makes them more or less
insoluble, depending on the length and intensity of its action. This
is in a few words the principle of the discovery."
The following text, which is very important and was
published at the beginning of the eighteen twenties, proves that Niépce's physico-chemical
principle (1) was known by the chemists.
"Comments on the solubility of resins and varnishes in
alcohol. After a series of very simple tests,
it's easy to convince ourselves that these substances are composed of
molecules the chemical properties of which vary depending on their
degree of solubility. We have to consider these substances as a
compound of parts : some of which are very soluble in alcohol at low
temperature or even by contact with alcohol; some other parts which
are less soluble require a higher temperature; and finally some on
which the action of air, sunlight or even heat of infusions leads to
some modification which is put in evidence by their resistance to the
action of the spirituous liquid. However these three parts
constitute an homogeneous whole in the resin.
There is only the dissolution
process which can show them in their real attribute. But
whatever the quantity of liquid which is added to the resinous
residue, it will not be possible to obtain a complete dissolution.
Thus, when we mix up too much matter with alcohol, it
firstly dissolves the most soluble parts and has got very little
dissolution effect on the less soluble ones. The dried parts of the
resin escape from the liquid's action if we only work at moderate
temperature. In this case, the varnish shows only feeble color, but
if it gains in elasticity, it loses consistency and solidity. It's an
advantage to combine these three qualities. We obtain such a
combination by using limited amounts and by operating with much more
care and slowness."
This physico-chemical principle
was the basis of the treaty between Niépce and
Niepce and Daguerre's research was continuously
directed by this physico-chemical principle.
Colored asphalt applied on a black
plate could not agree more
The initiative to provide a product photo-sensitive
In the instructions on the heliographic, Daguerre
indicates footer this important detail and obvious:
"The lightest shade that
gives this process is not white."
On February 26, 1830, so at the very beginning of the
association, Daguerre wrote:
"Bitumen of Judea seems to me, and you have the
necessary properties except the white
...... however we must look for the white and its opposite. Iodine
does not seem appropriate, it is always iridescent or greenish. "
In the same letter, the code adds
Daguerre agreed for correspondence:
This observation made by
Daguerre, the research will aim to meet these
Following an important observation of Daguerre, the two inventors in 1832 will make a discovery
and develop the physautoype
based on the principle of Niepce (bitumen).
invented the physiotype (resin).
We've already and often written that the process of
residue from Essence of Lavanda is not the physautotype !
The photosensitive varnish of the physautotype is
constituted with a compound of petroleum oil residue and of the
residue of the Essence of Lavanda. This same
residue was discovered by Daguerre. In this compound,
the photosensititve part is the petroleum oil
residue. Oil is classified in the family of
bitumen2. The varnish constituted of different proportion
of both residues being not colorated will give an image without
coloration: this was what Daguerre wanted3.
After exposition to the light, the image was obtained
with the successive actions of vapour of sulfuric ether and of liquid
solvent, this method was developped by the diorama's director.
Daguerre discovered the
sensitivity to light of the residue of the Essence of Lavanda
When Niepce died, our two researchers' work was at this
Then, Daguerre will bring out an
image thanks to petroleum vapours and this will constitute his contributions to
With the residue of oil
(physautotype) there is no latent image.
Concerning the name of the process using the residue of
the Essence of Lavanda, Jean-Louis Marignier, making a pretext of Daguerre's lapse of
memory, attributes the invention of the process to
Niépce as well. Daguerre, after Niepce's death, will mention physiotipe and not physautotype as the
appellation of this process.
Daguerre wrote to Isidore:
"Physiotipe or natural print".
This comes from Phusis = nature and Typos = print.
This demonstrates that Daguerre remembered the
Jean-Louis Marignier's argument
is not acceptable. His argument is
misleading and despoils Daguerre6, and reading the
correspondence demonstrates that Daguerre was
not mistaken and remembered perfectly the code developed by
Nicéphore Niépce. This process only belongs to Daguerre
and to convince ourselves of it, we only need to read Isidore
Niépce's comments on the subject in his lampoon against his
"As soon as Mr Daguerre was initiated into the secret
of Niépce's discovery, he kept really busy about
it : he replaced the bitumen of Judea used
by my father by the residue from the distillation of lavender oil;
there was an improvement about the whiteness of the layer which was
also more sensitive to the luminous flux; but, because of the
same reason, the destruction of the image was gradually brought about
even in the shade and was prompt and complete if the prepared
metallic plate was exposed to the light. This improvement could not
have a favorable result."
The names of the successive
processes are in direct relationship with the photosensitive product
Heliography = Judea Bitumen =
bitumen = physico-chemical principle of the treaty between
Niépce and Daguerre: invented by Niépce.
Physautotype = residue of
petroleum oil = bitumen residue = physico-chemical principle of the
treaty between Niépce and Daguerre: invented by Niépce
Physiotipe = residue of the
Essence of Lavanda = resin residue = physico-chemical principle of
the treaty between Niépce and Daguerre: invented by
Daguerréotype = silver
iodide = silver salt = physico-chemical principle different from the physico-chemical principle of the treaty
between Niépce and Daguerre: invented by Daguerre.
As we've already written2, the sensitivity
of the varnish and the visibility of the image will only depend on
the compounds which constitute the varnish.
After exposition to full daylight, the plate is dipped
in a liquid solvent, the image is stripped bare, the residue which
was not exposed to the daylight is dissolved.
When exposed to the vapours of petroleum oil, the image
is not stripped but developed because, in this case, the molecular
change (chaining of carbon atoms) of the residue, more or less
exposed, will be put in evidence by the vapours of petroleum oil.
The principle is identical in the Daguerréotype:
the vapours of mercury brings out, in the same way, the image
according to the exposure to light of the silver iodide.
1- Since Isidore's pamphlet and the polemic cleverly carried on
by the family (4), there is no choice but to accept that one doesn't
know how to read a contract!
-We've already mentioned that in the annals of the
"Société L J M Daguerre" published in 1989.
2- Daguerre and optics by J.Roquencourt in Etudes
photographiques n°5- 1998, notes 3 and 20 (Société
française de photographie).
3- See Daguerre's comment in his opuscule on the colour of the
process of Niépce. (page 39 in "edition Giroux")
4- It's possible that for Jean-Louis Marignier, Isidore can't
This pamphlet was reprinted in 1972 &endash;not for sale to the
general public- with a circulation of 1000 by the company
OFMI-GARAMONT*, with the contribution of André Jammes and
Janine Niépce. In it, you can find the photographs of the
first iris diaphragm, naturally attributed to Niépce, the
chamber with bellows which is nothing but the bellows of the
"Pyréolophore" as well as the "laid table" which is not by
Nicéphore. (We'll get back to that point later).
Jean Dereck, by way of warning, acknowledges that "the text may
suffer from a content and a tone more polemical than historical, no
doubt, (he writes), but we thought it was of the greatest interest to
remember the precariousness of Niépce's means and that he had
his share of all kinds of traps, and thus, specifying the respective
duties which the inventor respected…. If this small book somewhat
contributes to the acknowledgement and fame of one of the most
essential French invention, we'll have achieved our aim."
In his introduction, Jean Dereck quotes from Victor Hugo:
"Loving is half way to believing" and finishes by specifying that
this text has been republished as a tribute to Niepce.
Jean Dereck is dead; we would have liked to tell him how his
sincerity has been deceived.
*The firm Ofmi-Garamont has changed its corporate name to
Heidelberg France Company since March 31st, 1998.
5- See the summary written by Daguerre in his opuscule
published by Giroux about the "Modifications made by Daguerre to
6- This researcher wrote numerous articles spreading this
We denounce such a
- We confess to not understanding this researcher: he may
admire one of these inventors but why does he need to falsify
- Falsification of texts with the backing of the CNRS and the
Academy of Science!
- JL Marignier stands for the scientific authority of the
"House of Niépce" which is guaranteed by the Academy of
We'll point out that his works,
introduced as new, had already been carried out by Niépce de
Arago when tracing the past history of the inventions
of the processes of Niépce and Daguerre, points out that the
use of the residue of lavender as a photosensitive element and
petroleum vapours to bring out the image, are
solely Daguerre's achievements.
One could be surprised that not
one of the historians noticed the contradictions between JL
Marignier's affirmations and all the documented sources.
Commentary by Arago, page 16, in
the opuscule by Daguerre, in Giroux Edition.
"Mr Daguerre imagined a method which is named the
improved Niépce Method. Firstly, he replaced bitumen by the
residue from the distillation of the Essence of Lavanda, because of
its better whiteness and higher sensitivity. This residue was
dissolved in alcohol or ether. The liquid was then allowed to settle
in a very thin and horizontal layer on the metal which left a powdery
and uniform coating after evaporating. This result could not be
obtained by dabbing.
After exposition of the plate (prepared as described
above) in the camera obscura, Mr Daguerre put it horizontally above a
recipient which contained essential oil at room temperature. In these
appropriate conditions, one could appreciate at a glance that the oil
vapours left intact the spherical particulates of the powdery coating
which had received the action of a bright light. Vapours penetrated
more or less the same area of the coating which corresponded to the
halftones in the camera obscura."
Read too this copy of the Academy
of Science Report.
"…because in the last ones, the varnish is only
entirely removed when there are great intensity, and as the halftones
are only produced by more or less thickness of varnish, it's
impossible that acid reacts in the same proportion, which I've
already mentioned in a Note I added to Mr Niépce's process.
This drawback hasn't occurred any more since
I've modified the process and replaced the bitumen by the residue of
the Essence of lavender oil, and this residue dissolved in alcohol
and spread on a metal or glass plate doesn't produce a
continuous layer but creates on the surface a series of small
spherical particulates areas of resin which leaves in between the
metal bare. That's why it's possible then for an acid to etch the
plate and that's what I did using fluoric acid on a glass plate with
an image obtained with a camera obscura. To be able to see the
result, I darkened in black the parts of the glass eaten out by the
acid. But this image was very faulty because as the acid reacted on
the entire surface there wasn't enough gradation of tones. This is an
inconvenient which is impossible to avoid using only one acid on a
plate which was not especially prepared for it. These details are by
themselves sufficient to demonstrate that I worked on the etching of
images and that if I didn't speak about it in the description of the
modifications that I brought to Mr Niépce's process, it's
because I judged the results too imperfect. "
We publish below (in french) the
text changes only by the process of Daguerre and Niepce, Jean-Louis
Marignier has the imprudence to call Physautotype, allowing him to
attribute these improvements to the two inventors.
Napthe ou huile de pétrole
Après l'image latente avec le bitume de judée, avec les acides
c'est maintenant avec le physautotype que J L Marignier veut nous
démontrer que c'est Nicéphore le découvreur de
du site de la maison Niépce)
With oil residue
(physautotype) there is no latent image.
the image is visible,
the whites are slightly gray.
Removing the residual
oil or bitumen for other pure whites, Daguerre discovered the
sensitivity of the residue lavender and it is only in this case, the
image is often invisible.
After the death
of Niépce, it will show the image with oil vapors.
It is necessary that
this residue is pure, that is not the case with the oil residue and
the obtained image is visible.
techniques apprises auprès de Niépce, il inventera un
troisième procédé, le daguerréotype,
photographique praticable du fait d'un temps de pose abaissé
à environ quinze minutes.
procédé est bien entendu redevable à
Niépce car bon nombre d'aspects découlent de
l'héliographie. (J L
Rien n'est plus
contraire à la vérité. (Jacques
techniques learned from Niépce, he invented a third process,
the daguerreotype, the first
practicable due to an exposure time reduced to about fifteen
The latter method is
obviously indebted to Niépce because many aspects arising from
the engraving. (J L Marignier) "
Nothing is more
contrary to the truth (Jacques Roquencourt)
derangement of the mind is to believe things because we want them to
and not because we
have seen that they are indeed. "Bossuet.
Text written in July 1998 and put on internet in
November the 28th 2007.
- premières remarques dans les annales de la
Société L J M Daguerre 1989.
-** article de J B BIOT dans le Journal des Savants en mars
et avril 1839.
-Daguerre et l'optique : J Roquencourt.
Études Photographiques: n°5 1998
(Société Française de Photographie).
-Note sur le portrait de M Huet : J Roquencourt, A
Études Photographiques: n°6 1999
(Société Française de Photographie).
- L'invention de la photographie: une tragédie
-JL Marignier we wrote September 26, 1990, when we questioned
the presentation of his research: "you distort the results of my
research in making me say the opposite of what they show in a way
poutant so bright. .... for my part, I am not in the camp or in the
camp Niepce Daguerre ...... I want my research and experimental
results speak for themselves and their conclusions can be drawn ..
(underlined in the letter) "
May unscrupulous authors respect the intellectual
property and copyrights.