“You all know what mercury looks like-at room temperature it’s a silvery liquid that flows, it’s like a mirror. For the alchemists, and this is just a very short exercise in alchemical thinking, for the alchemists mercury was mind itself, in a sense, and by tracing through the steps by which they reached that conclusion you can have a taste of what alchemical thinking was about. Mercury takes the form of its container. If I pour mercury into a cup, it takes the shape of the cup, if I pour it into a test tube, it takes the shape of the test tube. This taking the shape of its container is a quality of mind and yet here it is present in a flowing, silvery metal.
The other thing is, mercury is a reflecting surface. You never see mercury, what you see is the world which surrounds it, which is perfectly reflected in its surface like a moving mirror, you see. And then if you’ve ever, as a child, I mean I have no idea how toxic this process is, but I spent a lot of time as a child hounding my grandfather for his hearing aid batteries which I would then smash with a hammer and get the mercury out and collect it in little bottles and carry it around with me. Well, the wonderful thing about mercury is when you pour it out on a surface and it beads up, then each bead of mercury becomes a little microcosm of the world. And yet the mercury flows back together into a unity. Well, as a child I had not yet imbibed the assumptions and the ontology of science. I was functioning as an alchemist. For me, mercury was this fascinating magical substance onto which I could project the contents of my mind. And a child playing with mercury is an alchemist hard at work, no doubt about it.
… I remember Al Wong once said to me, we were talking about the yin yang symbol, and he said you know the interesting thing is not the yin or the yang, the interesting thing is the s shaped surface that runs between them. And that s shaped surface is a river of alchemical mercury. Now, where the alchemists saw this river of alchemical mercury is in the boundary between waking and sleeping. There is a place, not quite sleeping, not quite waking, and there flows this river of alchemical mercury where you can project the contents of the unconscious and you can read it back to yourself.”
Terence McKenna, “Lectures on Alchemy“
“The bean“ in Chicago (via http://kenkenphotoblog.blogspot.ch/2011_04_01_archive.html)