(Batman Comics 008, 1941)
Professor Henry “Radium” Ross has things stacked against him from at least three different angles by my count. First, he’s a classic Victim of Orthodoxy as his research is rejected as too fantastic by a stick-in-the-mud institute director and he feels compelled to test his radium-based cure for death on himself. It works, but turns him into a radioactive man in the process, and he starts to go mad from a combination of radiation poisoning and (presumably) grief after he accidentally kills both his partner and his sweetheart (that’s angle no. 2, by the way).
The third misfortune to strike Professor Radium is Batman, who is much more of a protector of capital than he will be later and consequently is more concerned with preventing Ross from stealing the valuable drug that he need to treat his condition than with helping him get better. They fight and Prof Rad goes into the harbour, presumably to drown. OR DOES HE, the final caption box asks? No, depending on which comic book reality you live in. He makes an appearance as part of a squad of radioactive bad guys in Infinite Crisis, so at least one version of him evidently hangs out for up to 70 years before getting motivation to do some evil.
They should have brought him back beforehand (or used him since). He’s neat.
