As I write, I am in a couch in a large parlor looking out on an atrium with over a dozen marble pillars, onto another parlor on the other side. I have spent the day wandering around a college campus and enjoying the exploration. I've gotten little of the homework done that I meant to do (reading and writing about a theologian), and spent most of my energies trying to dodge the sense that the best way to explain what I want to explain about time is to begin with a classical form of alchemy. (The other alternative to lead into the discussion would be to start talking about Augustine, but that could more easily create a false familiarity. Alchemy is a more jarring image.)
Alchemy is one of those subjects most people learn about by rumor, which means in that case that almost everything we "know" about it is false. Trying to understand it through today's ideas of science, magic, and proto-science is like trying to understand nonfiction reference materials, like an encyclopedia, through the categories of fiction and poetry, or conversely trying to understand fictional and poetic works through (the non-fiction parts of) the Dewey Decimal system.
It is much more accurate to say that alchemy is a particular religious tradition, perhaps a flawed religious tradition, which was meant to transform its practitioners and embrace matter in the process. It may be rejected as heresy, but it is impossible to really understand heresy until you understand that heresy is impressively similar to orthodox Christianity, confusingly similar, and 'heresy' does not mean "the absolute opposite of what Christians believe." (Heresy is far more seductive than that.) Perhaps you may have heard the rumor that alchemists sought to turn lead into gold. The verdict on this historical urban legend, as with many urban legends, is, "Yes, but..."
Alchemy sought a way to turn lead into gold, but it