This study positions Paracelsian alchemy, medicine and medical physiology within the apocalyptic discourse of the Protestant Reformation. A comparison is made between alchemical theory concerning the perfectibility of prime matter and Christian eschatological doctrine concerning human salvation through Christ's sacrifice in universal history and in the ritual of the mass. A detailed analysis is made of the engraved illustrations constituting an integral part of the alchemical medicine and physiology of Heinrich Khunrath, Stefan Michelspacher, Jacob Boehme, Abraham von Franckenberg and Robert Fludd.