Medieval Islamic sword quenching practice

Tom's undergraduate history paper material — Muslim swordsmiths during the Middle Ages believed quenching a hot blade through a living person or in blood produced a better edge than quenching in water or oil.

I actually wrote my junior year paper, in the history department, on steel. And there are interesting ways over the years. The Muslims during the Middle Ages thought that the best way to quench the steel — you heat it up, it goes red-hot, and ordinarily you'd quench in water or oil — they liked to take a Nubian slave, a living person, and run the hot sword right up through, push it up. They felt it gave a better edge to the sword. So if you wanted a short-term profession, you'd be the quenching medium for Mr. Steel by the sword. Or sometimes they take the hot steel and quench it in blood rather than in water.