<< >it another try, I accidently chose the short stop instead.
>There was a fairly immediate foul pungent odor and it immediately
>dawned on me what had happened.
Cyanide gas (hydrogen cyanide) has a sweet odor, like almond or crushed
peach pits. The pungent odor was probably some sulfur compound - most of
them are foul (like hydrogen sulfide and the compounds they put in gas lines
so you can tell if there is a gas leak).
Still, not knowing what you were doing, you were quite smart to get out of
the area. The sulfur compounds can be very toxic in enclosed places. >>
Just to agree with what Sil says - the pungent odour was most likely to have
been sulphur dioxide - you can smell this when you light a match.
There is no risk with any normal use of ferricyanides. However all
photographic processing and particularly things like sepia toning should be
done in well ventilated areas. Adequate ventilation is essential in a
darkroom, and if you are doing non-standard processes it would be wise to
improve on this!
Peter Marshall
On Fixing Shadows, Dragonfire and elsewhere:
http://faraday.clas.virginia.edu/cgi-uva/cgiwrap/~ds8s/
Family Pictures & Gay Pride: http://www.dragonfire.net/~gallery/