The Collaborative International Dictionary of English v.0.48:

Alchemize \Al"che*mize\, v. t.
   To change by alchemy; to transmute. --Lovelace.
   [1913 Webster]

WordNet (r) 3.0 (2006):

alchemize
    v 1: alter (elements) by alchemy [syn: alchemize, alchemise]