[alt-photo] again on am fe citrate

[Alberto Novo]

I received also a reply from Peter Marshall: 

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Dear Alberto, 

I sent this to the group, but it seems not to have appeared 

In the reprint of the 1937 English second edition I have he states the 
average composition as:
brown (C6H507)2H2Fe2(OH)3)(NH4),3H20
(all the numbers are of course subscript, which my e-mail software doesn't 
do)
This formula seems to contains a spare brace -perhaps the French edition did 
it better! 

But it is all pretty academic, as the composition varies. If you have Mike 
Ware's Cyanotype book he looks at the chemistry in Appendix 3 (and there are 
some notes earlier in the text - find it in the index as 'ammonium ferric 
citrate') 

Regards, 

Peter 

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Alberto
www.grupponamias.com
www.alternativephotography.com/wp/photographers/rodolfo-namias-group