Toronto. Have you ever wondered where you could find photographic chemicals information on one site? One long time member suggests you look here on wikipedia.
The illustration is for ELON, Kodak’s brand name for Metol developer.
As a kid I used Metol/Elon and Hydroquinone as developers using formulae from Kodak in a then new Photo-Lab Index – a massive loose-leaf book with a pages/sections subscription that was the Wikipedia of the day for amateur (and some professional) photographers who ‘rolled their own” in the darkroom.
Note: The Photo-Lab Index link is to a free pdf of the condensed paperback version.