Stanislaw Ignacy Witkiewicz (a.k.a. Witkacy), born in Warsaw in 1885 e died - for an intentional drug OD - in 1939, was a Polish painter, illustrator, photographer, philosopher, musician and novelist. I met for the first time this interesting and unusual artist on the pages of the (now unfortunately deceased) Entheogen Review and recently he picked up my interest again repaging that same old issue of the magazine.
The article where Witkacy was mentioned, showed two paintings made under the effects of peyote and mescaline in 1929. The artist extensively experimented with various psychoactive substances - alcohol, cocaine, mescaline and peyote - and used them to get inspiration and access the visionary dimensions he then put on the canvas. Many consider him the first modern artist to work under the influence of classical psychedelics.
Unfortunately I couldn't find the above mentioned paintings on the Web; if interested, one can order the Entheogen Review back issue (Vol. XIII, nr. 1, Vernal Equinox 2004) on their site
You can find other Witkacy's paintings here and bio and exhaustive infos here