The yearning for knowledge often leads scientists to do things that would make the rest of us queasy. Charles Darwin famously ate every animal he discovered. He no doubt learned how they tasted. There are scientists who subject themselves to experiments that they didn't want to ask others to endure, or maybe they tried but couldn't get any volunteers. But occasionally, it was to prove another scientist wrong.
Of course that makes one curious about Max Pettenkofer, who had some wild ideas but was instrumental in promoting clean municipal water supplies. The stunt of drinking cholera water made him a bit ill, but he didn't develop a full-blown case of cholera. The examples here are pretty tame compared to the rest of the list at Cracked.