In the long history of strange mental disorders, glass delusion ranks as one of the most baffling. It appeared for the first time around 1400, and people suffering from glass delusion were convinced that their bodies were made of glass. Charles VI of France, the glass delusion king, may have been the first to suffer from the fear that his body could shatter.
Glass delusion was also known as scholar’s melancholy because it almost always struck wealthy, educated Europeans – the same group that had the resources to buy glass and reading glasses, which were new products in the 15th century. Across Europe, a Princess claimed she had been turned to glass, Miguel de Cervantes wrote about a scholar vagabond with glass delusion, and a glass maker believed his buttocks would shatter if he sat on a toilet.
Doctors devised extreme cures for glass delusion, including beating a man to prove he wouldn't shatter and burning the straw that one man used to protect his fragile body. Glass delusion wasn't the last of the strange mental illnesses from history– in fact, it was followed by cement delusion.
The unusual mental illness known as glass delusion appeared for the first time around 1400. People struck with glass delusion believed that they were literally made of glass. They were worried that their fragile and transparent bodies could shatter at any moment. Patients cried that they had been transformed into “a urinal, an oil lamp, or other glass receptacle,” – a urinal at the time meant a small glass flask used by physicians to examine urine.
A person suffering from glass delusion might believe that his entire body was made of glass, or that only some parts of his body were afflicted – such as glass shoulders, glass arms, and, in at least one case, glass buttocks. But after the 1830s, glass delusion faded away, replaced by a different terrifying mental illness.
The first known person to suffer from glass delusion was King Charles VI of France, who fell into madness in 1392. During his frequent mental breaks, Charles began to believe that he was made of glass. The King, who quickly gained the nickname Charles the Mad, was terrified that he might shatter. In order to protect himself, he had special clothes manufactured that were reinforced with iron, so that he couldn't crack.
Charles’s illness made it nearly impossible for him to rule his kingdom. At times, the King would sit completely still for hours to make sure he didn't shatter. He refused to let anyone touch him. And sometimes he hid in cupboards to protect himself.
King Charles of France was not the only royal to suffer from glass delusion. In the 19th century, Princess Alexandra Amelie of Bavaria was struck with a similar malady. Her royal parents noticed the young Princess walking sideways down the palace halls. When they questioned their daughter, her answer was baffling.
Princess Alexandra claimed that she had accidentally swallowed a glass grand piano as a child, and it had somehow transformed her body into fragile glass. The Princess was forced to move carefully at all times to avoid breaking.
The physician to King Philip II of Spain wrote about a case of glass delusion in the early 17th century. The physician claimed that the patient suffered so badly that he refused to leave his straw bed. Naturally so because the straw was the only thing that protected him from breaking. The physician reported that after burning up the straw, the man’s wits returned.
When English scholar Robert Burton wrote the Anatomy of Melancholy in 1621, he also included glass delusion. Burton wrote of men who were tormented by the fear “that they are all glass, and therefore will suffer no man to come near them.” Others, he claimed, believed they were made of cork or lead, or feared that their heads would fall off their shoulders.