The story
From a trade name, presumably a shortened form of the chemical name.
Etymology from Wiktionary, CC BY-SA 4.0.
metol
Today it means: The sulphate of 4-methylaminophenol, used as a photographic developer Full definition →
Today it means: The sulphate of 4-methylaminophenol, used as a photographic developer Full definition →
From a trade name, presumably a shortened form of the chemical name.
Etymology from Wiktionary, CC BY-SA 4.0.