There is an interesting saying here that goes like this: a closed mouth
gathers no feet;-)
...
>Our wager is not forgotten, it stands as a commitment to our differing
>beliefs. As a reminder, I think that the Fresson paper samples will
>contain both gum and gelatin while you believed that gum will not be
>present. Unfortunately, the testing has proceeded at a snails pace. In
I think the real reason why these tests are taking forever and a day is
that those conducting it know in advance that it is an exercise in
futility. They have better things to do with their time.
For conservation/restoration/provenance purposes, I have been using
scientific analysis of photographs for over 20 years, with the finest of
the equipment and scientists in the world. The bottom line is this: you
can't reverse engineer a process, period. There are tricks that some
manufacturers use to find out what others are doing but most of these
tricks don't involve chemical analysis and they are often not successful.
One such trick consists in buying the info from an ex-employee and this is
what is sending retired Kodak executive Harold C. Worden to jail for
industrial espionage against his former employer, as widely reported in the
press last year. Other "tricks", of course, are perfectly legal, e.g.,
inventions can be bought. Ugh? What a concept! I should patent it, quick!;-)
Last year (97), _Pour la Science_, the French edition of _Scientific
American_ published a most interesting article by Marignier (CNRS
scientist) on the first photographic process ever invented, by Niepce in
the 1820s: the bitumen process. After 10 years of work he has succeeded in
reviving the process, not because of his analytical work, but because he
had enough of the formulas left by Niepce's correspondence with Daguerre.
If it had not been for that he would never have succeeded, as only a
precise series of steps involving heating, dissolving, distilling, coating,
etc, at specific temperatures and for specific periods of time, etc., could
make something work. If you change one variable, nothing works!
The odds of winning the lotery are much better than stumbling across the
perfect solution for any of these processes.
Good luck.
Luis Nadeau
NADEAUL@NBNET.NB.CA
Fredericton, New Brunswick, Canada
http://www3.nbnet.nb.ca/nadeaul/