A book I randomly picked up and read because it looked nice, haha.
It's actually really great, giving a quick but broad overview of the history and philosophy of alchemy. It tells a useful story, of how a protoscience, a 'chemistry of spirit', developped in accordance with dominating schools of thought: the Aristotelian, forcing its way through the centuries, through Zosimus, Jabir and Lull, changing slightly but not significantly, until it faced the enlightenment, branching off into chemistry and the Hermetic tail end of alchemy.