I think my report to Sandy was a little garbled or something. My experiment used a 100 ml of glycerol (also callsed glycerin) to hold the Metol and ascorbic acid. Heat it to 250 but no higher than 300 F.This heating drives the water form the hygroscopic glycerol. Now add 4 grams of ascorbic acid, stir it well and add 2.5 grams of metol. The result should be a clear yellow-orange soultion which will remain clear as it cools. Now add 50 grams of catechol and enough propylene glycol to make a liter. Heating helps dissolve the catechol, and it won't hurt to make it hot enough to boil off any water that might be in the glycol. The stock solution becomes considerably redder when the catechol is added.

You may find other uses for the glycerol solution of Metol and ascorbic acid. I made a double batch just so I'd have some to play with. I used the extra to make a water based Pyrocat MC stock just to see how long it would last. I'll tell you a year from now how it faired. Its pH is about 3, which should help it keep a while.

I don't think the glycerol mix is a simple solution. For one thing, only 1 gram of Metol should have remained dissolved on cooling. I have my own ideas about what chemical reactions may be going on between the H2SO4 of the Metol and the glycerol at 250 F but I rely more on pracrice than on theory, especially if there are two or more theoretical explanations.