The hypochondriac is the butt of jokes. Even his butt is the butt of jokes. A story doing the rounds in the 16th and 17th centuries concerned a Parisian glassmaker who, believing himself to be also made of glass, fastened a cushion to his buttocks in case they broke when he sat down. His anxiety
Glass delusion, the bizarre belief in your body being made of the transparent, fragile material, was found among several educated people from the 14th-19th centuries.