zodiac9 Feb 2006
At the time when he wrote this and other passages in the book, Hugo was probably the best-versed person on Medieval Alchemy in the world. Disney probably wasn't so interested in that.
I can't remember my old annotated Hunchback, but I believe "Emen-Hétan" is either the name of the Wandering Jew, revealed to Solomon, or the magic word the Wandering Jew revealed to Solomon. Anyway, try googling "emen hetan" (without the diacritical) for fun.