@xahlee @jeremiah I'm not sure it *was* done for food preservation a thousand years ago, but it's easy to make by burning sulfur. If you already have wood smoke preservation it's not a huge leap to say "Hey, sulfur burns with very smelly smoke, maybe that could be a good preservative!"
@mattskala @xahlee most ancient food preservation was of six kinds: burying/candying, fermentation, salting, spicing, smoking, or desiccation. Within smoking might be use of sulphur products, though I doubt knowingly so. Article on ancient egyptian honeyed preserves: http://bit.ly/2k2VjU8