"I would be sitting under the same glass bell jar, stewing in my own sour air"
Cake platters and bell jar (left)
Creative Commons AttributionCake platters and bell jar (left) - Credit: Anthony Easton, Flickr

The idea of being confined within a bell jar is, of course, the novel's central metaphor for Esther Greenwood's experience of mental illness.

It is a particularly striking image, which conveys both the isolation and desolation of being imprisoned in a 'world of one's own', and the sense of stifling helplessness evoked by being unable to escape from that world.

In Jacqueline Rose's critical analysis* of the work of Sylvia Plath, she notes that one of the characters in the well known film, Barbary Coast (1935), says, 'I was born in a bell jar'.

*Jacqueline Rose, The Haunting of Sylvia Plath (Virago, 1992 paperback edition) p. 186