This is an interesting developer, which I picked independently of Photrio first from a booklet of Alfonse Cuisinier. There is development time of 14 minutes, but not much else, accompanying the formula, only that “According to its author, this developer gives images whose contrast is more normal than that of the images generated by the D-76.”
In a subsequent private conversation Ian gave me some info about the developer author, that is rather difficult to find, thanks Ian, for your efforts. This person was a well-connected amateur. IMO, a replacement of hydroquinone with pyrogallol, despite them both being hydroxybenzenes, is non-equivalent. I do not have any data that metol is superadditive with pyrogallol, but I know that pyrogallol activity is very dependent on pH, and at pH 8 is practically zero, while above 9 it is quite substantial. BTW, all other pyro-metol developers I know have a significantly higher pH (9.0-9.5 or above). In comparison, hydroquinone has zero activity at pH 10 and below and exhibits apparent weak superadditivity with metol.
So, I was intrigued and made small portions of this developer, adjusted to pH 8.2, 8.5 and 9.2., in pairs of plus or minus pyro. Without boring you with curves, I can say that at pH 8 there is no difference between the images generated by development in a solution plus or minus pyro. At pH 8.5 there is a subtle difference, primarily in the highlights, but IMHO only a highly trained observer will be able to see it. So, pH 7.6 mentioned in the BJP text clearly does not fit. My results could be explained by suggesting that my pyro lost activity, but the other two developers I made recently are performing according to expectations.
So, we are dealing here essentially with a soft-working metol-sulfite like diluted D23, which, depending on the quality of sulfite, will have somewhat better highlight discrimination. Oddly, with sulfite of worse quality the visual appeal of the images may be stronger and the development time considerably shorter. With tight pH control, one can arrive at a very personal highlight control developer, not easily achievable with D-76. I do not know how well it will keep, but within two weeks of my humble experimentation the initial pink color stayed constant, despite use. I hope this helps.
