In "When We First Met", we spotlight the various characters, phrases, objects or events that eventually became notable parts of comic lore, like the first time someone said, "Avengers Assemble!" or the first appearance of Batman's giant penny or the first appearance of Alfred Pennyworth or the first time Spider-Man's face was shown half-Spidey/half-Peter. Stuff like that. Today we reveal when Superman's magic vulnerability began!
To be clear, Superman doesn't technically have a specific magic vulnerability. He is not MORE vulnerable to magic than other people. It's just that he has no special defenses against magic, and thus, something that would magically affect a typical person would also affect Superman. Sometimes, writers (especially Justice League of America writers) so desperate for something to slow Superman down would often act as if magic was a special problem for Superman. It is not.
So anyhow, when did Superman first show that magic could affect him?
That would be in Superman #14, in a story by Jerry Siegel, Leo Nowak and John Sikela, when Superman is enchanted by a spell by an undersea magician...
However, Superman soon broke free of the spell by just concentrating really hard (although, I suppose that the same could have been achieved by Batman if he did the the same thing)...
This being the Golden Age, however, no one was necessarily keeping track of how Superman's powers worked, and so a year later, in Superman #26, in a story by Don Cameron, Dick Sprang and San Citron, Superman faces off against Mercury, who uses his magic staff on Superman and is shocked to learn that Superman is impervious to its powers!
For the next decade or so, that was essentially the case for Superman and his magic weakness. It came and went with seemingly no consistency. In one story, he was vulnerable to magic while in another story he was impervious to it.
Finally, Superman #171 made what I assume was Mort Weisinger's definitive statement on the topic, which is that Superman is susceptible to magic, in a story by Jerry Siegel, Curt Swan and George Klein...
Justice League of America would debut soon after and that book famously talked about Superman's two major weaknesses constantly (as Gardner Fox always had to find ways to write Superman out of stories, as I pointed out recently here), so it was soon ingrained into the minds of fans everywhere that Superman was vulnerable to magic.
If you have a suggestion for a future edition of When We First Met, just drop me a line at firstname.lastname@example.org!