One of Blake's 'Spiritual Visitants'

John Varley was a watercolourist, landscape designer and astrologer whom Blake met towards the end of his life. Varley encouraged Blake to sketch portraits of the people who populated his visions, and in all there are between forty or fifty drawings of such 'visionary heads'. Many of these depict historical characters, such as kings and queens, but the most popular has always been the flea, which exists both as a simple sketch and as this elaborate painting.

Blake claimed that, while he was sketching the flea, it had explained to him that fleas were inhabited by the souls of bloodthirsty men. These bloodthirsty men were confined to the bodies of small insects, because if they were the size of horses, they would drink so much blood that most of the country would be depopulated.

The flea's bloodthirsty nature can be seen in its tongue, darting eagerly from its mouth, and the cup (for blood-drinking) that it is carrying.

The poor quality of this picture is due to Blake painting it in what he called 'fresco' (tempera), which has cracked and dulled with age. The influence of Michelangelo (1475-1564), a Renaissance artist whom Blake admired, can be seen in the highly defined musculature of the flea's burly body.