Stefan Glass was one of the artist’s closest friends. Glass was a mathematician, philosopher, poet, translator, author of a chapter on ether in a Witkiewicz pamphlet on drugs (signed as Dezydery Dr. Prokopowicz). Glass was a frequent participant in the Zakopane clique surrounding Witkacy, who continued his earlier controlled experiments with various drugs (morphine, cocaine, peyote, and others). Witkacy painted and wrote under their influence. He also recorded, in small notes on his paintings, the drug that was influencing him at the time, even if it was only a cup of coffee.

More on Witkacy from Wikipedia.