Re: Daguerreotypes again-mercury (OT)

Perhaps some Light reading is in order. ; )

Actually, The use of Iodine was Niepce's discovery.
Niepce's process of Heliography from 1827
utilized Iodine vapor to fume the bitumen
covered silver plate. (he abandoned tin in favor of silver by that time).
This produced a positive image once the bitumen was
removed in the usual way.

Daguerre and Niepce began their partnership
in December of 1829 with the aspiration of improving
the speed of the Heliography plate.
Prior to this partnership, Daguerre had experimented
with many substances including his experiments during 1824 using
phosphorescent substances and a small disc of blue glass.

-see Comtes rendus ; February 18, 1839 p.243

The second photographic process was invented by the
partnership of Niepce and Daguerre in 1832 and was
known as the Physautotype. This one has slipped by
most photo historians.

The collaboration between the two men was much
greater than had been thought by earlier scholars. The only
thorough documentation of their correspondence prior to very
recent times was printed in Russian in 1949.

Niepce died suddenly of a stroke in the summer of 1833 at the age of 67.

Daguerre was later to invent the process that bears his name after
eleven years of experimentation. One can only imagine how many
disappointments in his experiments that he encountered in those years.

Now, to the point of how he came to use Mercury vapor; the following
is part of a quote by Daguerre when asked about the discovery. It was
printed in "La Photographie consideree comme Art et comme Industrie",
Paris, 1862 - Mayer and Pierson

...he went on to explain by what processes he had eventually achieved
success step by step. " I first tried corrosive sublimate [bichloride of
mercury];
it marked the images a little, but coarsely, I then tried sweet mercury
or calomel
[subchloride of mercury]; this was already better. That day, hope
returned to
me more than ever, and brought back my old zeal. From this, it was only a

short step to the vapours of metallic mercury, and good fortune led me to
take it."

In later years, after the Daguerreotype became a sensation, Daguerre
continued his experimentation and developed two methods of
increasing the speed of the plate. The method that was published
in 1844 was the first time that Platinum was used in photography.
His un-published method from a few years earlier had not been
repeated successfully until a couple of years ago.

see:

-"Dokumenty po istori izobreteniia fotographi"
edited by Torichan P. Kravets 1949
(reprinted by Arno Press in 1979)

- "Heliography - New Light on the Invention of Photography"
-Jean-Louis Marignier
The Daguerriean Annual 1996

-"L.J.M. Daguerre" - Helmut and Alison Gernsheim 1956

-"Joseph Nicephore Niepce - Correspodances 1825-1829
Pierre G. Hartmant 1974

-"Niepce, Correspondence et papiers -Jean-Louis Marignier 2003

-"The Physautotype" -Jean-Louis Marignier
The Daguerrian Annual 2002-2003

-"The Silver Canvas" - Bates Lowry and Isabel Barrett Lowry 1998

-phillip

Ryuji Suzuki wrote:

> From: Phillip Murphy <pmurf@bellsouth.net>
> Subject: Re: Daguerreotypes again-mercury
> Date: Wed, 25 Aug 2004 06:41:35 -0500
> Ryuji,
>
> >This repeated tale is strictly for the tourists.

> > The discovery of the Daguerreotype process
> > was made with considered and methodical experimentation.
> > A major contributor to this discovery was his partner
> > Niepce who's goal was to create a new form of lithography.
> > Unfortunately, Niepce died unexpectedly and the research
> > which they had shared became the groundwork for the experiments
> > that led to the discovery of the Daguerreotype.
>
> That's not likely. Niepce disclosed his knowledge (bitumen based) to
> Daguerre when Daguerre visited Chalon at the end of 1820's. Daguerre
> did not seem to have significant achievement at that time. After that,
> Niepce did not contribute much to the pool of knowledge between the
> two. Daguerre wrote Niepce about silver iodide, but Niepce did not
> seem to be interested. Niepce and Daguerre probably did not get what
> they expected from their contract. So, practically speaking, Daguerre
> was on his own since then. Is seems that no one saw Daguerre working
> on his project and there is no hard evidence I could find about how he
> discovered development. The cupboard story is the only plausible
> explanation given in the literature I found so far.
>
> I could not find any record of methods of his experimentation that
> lead to discovery of his development (other than stepwise removal of
> chemicals from the cupboard). As you see in their modified contract,
> Daguerre cared more about him getting the credit than money. A man
> with that kind of spirit would disclose details of methods at some
> point if it were discovered as a result of methodical experimentation
> as you proposed.
>
> Ryuji Suzuki
>
Received on Wed Aug 25 22:54:46 2004