Alan, thank you very much for preparing the 'formula' for Emofin based on the MSDS.
Starting with your question, does the ppd in Emofin contribute to speed, the conventional answer is no. On p. 68 of FDC, I summarize Crawley to the effect that, where ppd is combined with a more active developing agent (and metol certainly is that), then the more active agent is almost exclusively responsible for development and the ppd's function is only to produce solvency.
Now that is only one explanation, and it may not be the correct one, or if it generally is, may not, for some reason or another, apply to this formula. But let's suppose it does. Then what we have is a metol-based two-bath with a much higher pH than usual (the most famous two-baths in the English speaking world invariably using borax or Kodalk for the second bath).
The 'method' used to gain speed increase is dilution, in this case accomplished by the nature of two-bath development. A similar technique is used today for single-bath developers. For example, when XTOL is used for push processing, Zawadzki and Dickerson found that the best approach was to dilute further and develop longer -- as shown in the original time sheets that accompanied the developer. Time and time again, some sort of compensation mechanism has been shown to be the only valid chemical technique to increase film speed. Crawley has also made similar recommendations, and both authorities suggest that this is particularly the best method when dealing with tabular grain films.
Looking at chapter 7 of FDC on Google I see that practically everything discussed in this thread is covered there, including Dignan's erroneous claim re Microdol.
Dan, when I said the assertion that Dignan's assertion re Microdol was erroneous, I was referring to Dignan, of course, not to you. I must say I also doubt that Dignan had any effect on Kodak's treatment of phenidone in MSDS statements. There are some hints in the literature of toxicity with phenidone, but it seems to depend on oral consumption, so provided you don't drink your developer, you should be OK.
In sum, I think Emofin is a speed-increasing, compensating metol developer, which uses ppd to decrease grain. One interesting thing about the fine grain mechanism in Emofin, in comparison to Microdol, is that the ppd probably decreases grain evenly throughout the tonal scale. It has been established that sodium chloride is proportional in effect, working preferentially on the highest levels of exposure. Since those are the areas where grain may be more visible, there may be some theoretical advantage to this, and it is certainly an elegant mechanism. (If I recall correctly, grain is most visible in the midtones.) But Emofin may easily be a superior developer to Microdol, although it most certainly is more expensive to manufacture and is probably considerably more toxic. It also appears that Emofin increases speed, while Microdol decreases or, diluted, at best, maintains it.
It would be interesting to have, with contemporary materials, comparisons of Emofin versus Microdol, and also Emofin versus the MSDS-derived formula. Working within the parameters of the MSDS, I would suggest:
A: ppd sufate, 10g
sod disulfite 1.5g
metol 5g
Sod sulfite 72g
B: sod carb anhy 30g
sod sulfite 35g
adjusting any amount as necessary to reach the specified target pH values the MSDS provides.
Finally, please don't take any of my explanations as authoritative. I'm only stating the balance of conventional probabilities. Other things may be going on here, and there could be any number of additional unlisted ingredients at 1-2% or less that could be having an important effect. All I want to say is that I see nothing in the Emofin MSDS that seems inconsistent with the claims made for the developer.
