Preceding modern chemistry, in the Middle Ages the art of alchemy spread out from the Arabic world, also reaching the Basel area. The alchemists were in search of ways to produce gold from other metals and, lastly, in quest of the alleged panacea, the philosopher’s stone.

Under the Ringelhof in Petersgasse a laboratory dating back to the 13th century was discovered. Whether alchemists had once worked here remains unclear – what one does know is that the place was used for processing different metals.