Stromeyer made his discovery after a request from the government to inspect the pharmacies in the town of Hildesheim, Germany.
In those days zinc oxide was used, as it still is, to treat skin conditions. For some reason, Hildesheim’s pharmacies were selling zinc carbonate rather than the usual zinc oxide.
Stromeyer was aware that heating zinc carbonate until it was red hot would convert it to the oxide. He did this with samples from the pharmacies. He found that the brilliant white carbonate turned into an oxide which ought to have been white, but was in fact yellow/orange.