The youtube channel has a lot of music videos for various history topics. Can’t promise I’ll never post another one, because some of them are pretty cool.
For this video in particular, I’d never actually heard about the the tongue turning black before. On the All Empires History Community (sources at the bottom of their page), they mention a white coating on the tongue and later, that the tongue might turn yellow or brown. Not black, though. Anyone know anything about that?