The Delusion of Glass

The first medical report of the condition may have been around 1561 and it was in a treatise by the Dutch physician Lemnius. Charles VI of France also allegedly had this condition and believed that his whole body was glass. Some people were even afraid that loud noises would break them. At the time this delusion was tied to melancholy and it was generally among people who were very isolated and withdrawn from the company of other people.