rurmonas@senet.com.au
Date: 12/06/02-06:05:36 AM Z
Quoting Liam Lawless <liam.lawless@blueyonder.co.uk>:
> Note that KOL said Herschel developed the "dirty yellow image" with
> ferrOcyanide. I thought it was probably a misprint, but maybe not.
Either ferricyanide or ferrocyanide can be used. Ferricyanide
reacts with the exposed FAC (ferrous state) to form Ferrous-Ferricyanide
(prussian blue). This is a negative process. Alternatively ferrOcyanide
will react with the unexposed (ferric state) FAC to form prussian blue.
This is a positive process.
Richard
--- Richard Urmonas rurmonas@senet.com.au ------------------------------------------------- This mail sent through SE Net Webmail http://webmail.senet.com.au
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