Had a transcendental storm of colour visions today in the bus going to Marseilles. We ran though a long avenue of trees and I close my eyes against the setting sun. An overwhelming flood of intensely bright colours exploded behind my eyelids: a multi-dimensional kaleidoscope whirling out through space. I was swept out of time. I was out in a world of infinite number. The vision stopped abruptly as we left the trees. Was that a vision? What happened to me?
Brion Gysin, diary entry, 1958
excerpt from On Acid: A Field Guide to Altered States (p. 50-51)