This video from Weird History is titled "Major Medical Discoveries That Happened By Mistake." That's really a misnomer, as most of these breakthroughs are anything but mistakes. It would be more accurate to say they were made by accident. Medicine and devices that were developed for one reason ended up being very successful for a different application. There's no real "mistake" in that! These ten stories cover some things you read about before, and a few you probably haven't. I was tickled to learn where vaseline actually came from, although that story really has no mistakes or accidents involved in it. I'd never heard the false story about Fleming's sandwich leading to penicillin, because we had the real story here years ago. The story about Edward Jenner doesn't appear to be an accident at all, but we all need to know it anyway. Overall, if you take this as just a list of medical breakthroughs alone, it's both edifying and enjoyable.