Re: Modifying bleaches

From: Charlie Goodwin ^lt;[email protected]>
Date: 12/01/04-11:40:52 AM Z
Message-id: <>


That is one of the items I was most wondering about. Reading about ferricyanide brings you to such warnings, yet the DuPont formula has no such warning as listed in "The Darkroom Cookbook". I am very glad you have reiterated the issue for me.


> Charlie, Ferricyanide decomposes and give off cyanide in presence of
> acid or strong light. I would not mix any acid to ferricyanide if you
> are not very familiar with it. Cyanide gas is said to have practically
> no odor and you may not notice its occurrence and accumulation in your
> darkroom until you get poisoned. A gas like hydrogen sulfide is
> probably just as toxic but at least you can strongly smell it at much
> smaller concentration than the point where you get poisoning, so I
> feel much easier.
> There are lots of formulae in popular darkroom literature that are not
> currently used. Some of them were dropped because they don't have any
> advantage. Some were outdated because they don't work with modern
> materials. Some were abandoned maybe because of other
> reasons. Whatever it is, a lot of darkroom formulary compiled on paper
> or on web are cut and paste work from old stuff without tracing
> whether/why each particular formula is obsolete, and I feel that not
> many of those darkroom formulary compilers test on their own to verify
> the advertised claims to go with the formula. Then some reprinted
> formulae have somehow important instructions, remarks, safety
> precautions, etc. left out. Richard can give you lots of examples like
> those.
> --
> Ryuji Suzuki
> "People seldom do what they believe in. They do what is convenient,
> then repent." (Bob Dylan, Brownsville Girl, 1986)
Received on Wed Dec 1 11:41:59 2004

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