One Panel #278-279: Don't Shazam Blind!

From Captain Marvel: "Mystery of Marvel College" by Bill Parker and C.C. Beck, Whiz Comics #11 (December 1940)

What happens when Billy calls the lightning without the benefit of sight?

From Johnny Thunder: "Johnny's Date" by John B. Wentworth and Stan Aschmeier, Flash Comics #12 (December 1940)

All sorts of weird things, like combining stray rams and giraffes that are in a completely different comic, for starters.