Quote Originally Posted by albada View Post

EDIT 2: Looking into this some more, I see that the MSDS for DD-X specifies (1) Boric acid (Michael R mentioned this), (2) Dimezone S instead of Phenidone, and (3) DTPA instead of DAPTA. So I'd say the patent was for an early formula which the engineers improved later. Based on quantity-ranges in the MSDS, I'd say this is similar to DD-X. Given this patent-formula and the MSDS, it wouldn't be hard to reverse engineer the present formula. Anyone want to try it?

Mark Overton
The switch from Phenidone to Dimezon S in Ilford liquid developers seems to co-incide with the change in sub-contractors producing Ilfords chemistry.

Older MSDS data for these developers is very much more informative, they show that Phenidone was used originally in DDX.