U of S | Mailing List Archive | alt-photo-process-l | Re: ferri sesquichlorati

Re: ferri sesquichlorati

Hi :-) have had some interest in sesquichloride of iron

Here with pigmented gelatine, roughly after "The Silver Sunbeam" recipe, too
thick layer of gel - sharpness bad. Positive process, I had no luck with
gum, but did not try very hard...

Sensitivity pretty low, this is 30 minutes exposure with a 2kw metal halide
bulb at 75 cm. The white parts are the exposed areas Thick layer is partly
to blame for the low sensitivity.


Copy paste whole link.

I believe there is some connections to the pellet process too and the
Ferro-Gallic...(??) at least chemicals involved are about the same.


If anyone know/understand the chemistry behind this I would be interested...
Have some theories, this process have been a background interest for a

(Combination of ammonium ferric citrate + tartaric acid in gelatine did show
tendencies towards a similar result, that was an accidental mixture.)


On 10/18/06 8:29 AM, "zphoto@montana.net" <zphoto@montana.net> wrote:

> Thank you, Neil!  Yes, this is in a book from 1900, so it is
> an old term.  It is a gum process wherein you include this
> in the gum mix!  I was going to give it a go.  But I guess I
> don't have ferric chloride so it'll have to wait.  I do have
> lots of FAC.
> Sometimes it is such a pain figuring out how to translate
> old chemistry terms.
> Chris
> ----- Original Message Follows -----
> From: NEIL MILLER <nkd.miller@btopenworld.com>
> To: alt-photo-process-l@usask.ca
> Subject: Re: ferri sesquichlorati
> Date: Tue, 17 Oct 2006 15:53:14 +0100
>> I think it's the same stuff as in Towler's "The Silver
>> Sunbeam," 1864, as sesquichloride of iron, aka ferric
>> chloride.
>> Regards,
>> Neil.
>> ----- Original Message -----
>> From: "Christina Z. Anderson" <zphoto@montana.net>
>> To: "Alt, List" <alt-photo-process-L@usask.ca>
>> Sent: Tuesday, October 17, 2006 3:17 PM
>> Subject: ferri sesquichlorati
>>> Help!  Chemists, what is this "ferri sesquichlorati"?
>>> Ferric ammonium citrate?  Ferric oxalate?  Potassium
>> ferricyanide??? I think it is a German
>>> word??
>>> Chris