Mike Ware, who might still be lurking on this list, is looking into this
from a scientific point of view. Considering his experience with past
articles on those other iron processes (e.g., Pt, Chrysotype, etc.) he
should be in a good position to know more after some further investigation.
He just posted a message to this effect on the Conservation Dist List. The
archives can be found on the University of Stanford Web server, which has
its own search engine. Check my URL below if you need more info.
Luis Nadeau
awef6t@mi.net
Fredericton, New Brunswick, Canada
http://www.primenet.com/~dbarto/lnadeau.html