On April 19, 1943, Albert Hofmann intentionally took 250 micrograms of LSD to further explore its effects. He described his second trip in horrifying terms.

“Kaleidoscopic, fantastic images surged in on me, alternating, variegated, opening and then closing themselves in circles and spirals, exploding in colored fountains, rearranging and hybridizing themselves in constant flux,” Hofmann wrote. “It was particularly remarkable how every acoustic perception, such as the sound of a door handle or a passing automobile, became transformed into optical perceptions. Every sound generated a vividly changing image, with its own consistent form and color.”

For his part, Hofmann reportedly took LSD hundreds of times and felt it could be used to help humans understand our place in the natural and spiritual world. However, Hofmann also believed LSD could be dangerous and discouraged the use of the drug recreationally, asserting that it should be a controlled substance.