DEVIL ON NIGHT-CHAIR It is presumed that somehow Bosch had knowledge of the Visio Tungdali, a twelfth century handwriting that describes a vision of a journey through hell. This was possibly the basis for this devil, crowned with a cauldron, symbolising the diabolical inferno fire. He is sat on a night chair, which offers him the possibility of excreting the gorged souls. His curious footwear in the shape of pitchers symbolises dipsomania.