Tons of information in the old stuff. You get some of the best information by poking around the literature that came out just before Kodak et al came into existence and gobbled everything up. Obviously we know some of it has been proven incorrect but I think it is positively amazing what those guys knew!
So, last night I worked the Steigmann's formula backwards and came up with the following in reference to the article Laboratory-Scale Photographic Emulsion Technique by Thomas T. Hill (9/1996) that D used as her source.
The emulsion he shows (Full-Ammonia Bromide) is sensitized as:
GOLD: 7.4x10-6 mol/mol Ag or ~3mg/mole Ag (as HAuCl4)
SULFUR: 3.2x10-4 mol/mol Ag or ~24mg/mole Ag (as NH4SCN)
The numbers seem plausible from what I have researched. Denise, PE et al, what do you think?
And I am correct in understanding that Steigmann's sensitizes for both GOLD and SILVER, yes?
What do we gain by using Na2S2O3 rather than NH4SCN, other than twice the sulfur?
And, PE, when you say 3:1 for S to Au, you are talking about quantity not moles, right?
Long post. Anyway, if I've got the numbers right I may have answered my own question.