“The drug finally produced faint illusions, chiefly ceiling as decorated with colored designs, and finally sleep.”

An 18th-century Jesuit’s account of ayahuasca usage in the Amazon basin.

The psychologist William James takes a high dose of nitrous oxide and thinks about Hegel. A fascinating and hilarious early foray into the “trip report” genre.

Luisa de Álvarez de Toledo discusses the use of LSD in "combined therapy,” focusing on how LSD facilitates psychological insights.