Plural of alchymy; multiple instances or varieties of the medieval pursuit of transmutation and magical transformation.
From alchymy (archaic form of alchemy) + -ies suffix (plural). Shows how English once used -y nouns with -ies plurals, like lady/ladies.
Using 'alchymies' in the plural suggests there were different schools or methods of alchemy—in fact, Islamic alchemy was very different from European alchemy, and Chinese alchemists had their own completely separate traditions.
Complete word intelligence in one call. Free tier — 50 lookups/day.