Stone of madness
Hypothetical stone in medieval folklore / From Wikipedia, the free encyclopedia
The stone of madness, also called stone of folly, was a hypothetical stone in a patient's head, thought to be the cause of madness, idiocy or dementia. From the 15th century onwards, removing the stone by trepanation was proposed as a remedy.[1][2] This procedure is demonstrated in the painting The Extraction of the Stone of Madness by Hieronymus Bosch.[3]
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Hieronymus_Bosch-Removing_the_Rocks_from_the_Head-Detail.jpg/220px-Hieronymus_Bosch-Removing_the_Rocks_from_the_Head-Detail.jpg)