"sreenath" wrote in message
oups.com...
This is 2nd English edition, and L.P.C does state in the
foreword that
references have been intentionally left out.

I searched through the book again, and found that the
original paper
is by Lumiere and Seyewetz, 1905.

Here is the exact text :

"It should, moreover to be noted that several developers,
particularly
HQ and paraminophenol), if added i very minute quantity to
a solution
of sulphite, retard very markedly the oxidation of the
latter by
oxygen of the air(Lumiere & Seyewetz, 1905). They probably
oppose the
catalytic action of various metallic salts, especially
copper salts,
which may be present in quantities so small as to escape
detection"

In another page, he states the quantity of developer to be
added as 5
gr ( I think grains) to 20 Oz of sulfite solution.

Perhaps this is no longer of practical significance.

I find this book really fascinating.

thanks,
Sreenath

Both hydroquinone and paraminophenol and its relative
Metol, are very active reducing agents, i.e., they absorb
oxygen. There may be some mutual protection where both
sulfite and one of these developing agents is included. If
so, it would suggest that the liftime of low pH developers,
like D-23 or D-25, is longer than the lifetime of a similar
concentration of sulfite. I don't know how to prove this
since I am not a chemist. One clue may be that the shelf
life of Kodak Hypo Clearing Agent, which is a neutral pH
buffered solution of sodium sulfite _does_ have a shorter
shelf life than many relatively low pH developers. I will
have to dig out my edition of Clerc and find this. I have
both the first and second edtions in translation plus the
later Focal Press edition in 5(?) volumes. I agree that its
a fascinating book.
Lumiere and Sayewetz are very respectible researchers and
photographic pioneers.

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Richard Knoppow
Los Angeles, CA, USA