Oliver Sacks article in the New Yorker titled ‘Altered States‘ and subtitled ‘Self-experiments in chemistry’ covers what he experienced and learned when he began doing drugs. The curiosity arose in his thirties when he felt a suspicion that he had never really seen the color indigo.

One sunny Saturday in 1964, I developed a pharmacologic launchpad consisting of a base of amphetamine (for general arousal), LSD (for hallucinogenic intensity), and a touch of cannabis (for a little added delirium). About twenty minutes after taking this, I faced a white wall and exclaimed, ‘I want to see indigo now — now!’

The resulting experience, and surely many others besides, should appear in detail in Sacks’ upcoming book [amazon asin=1594136491&text=Hallucinations].

via OpenCulture