leprosity

noun3

1. •
   The supposed impurity or impurities of various metals, understood as causing their deviation from gold.

   • The purpose of physical alchemy—as opposed to its various spiritual pursuits—was to treat the leprosity of base metals such as lead, refining and purifying them into gold.
2. •
   (no longer used) Synonym of leprosy in its various senses.
3. •
   (no longer used) Synonym of scaliness.