Dirt is dust, soil, refuse, excrement, bacteria, filth, sleaze, slime, smut. How easily the word changes its meaning from the physical to the moral. It is this fascinating relationship and threat which dirt seems to pose that is explored in the Wellcome Collection's exhibition 'Dirt: The Filthy Reality of Everyday Life'. In a special edition recorded with an audience of the public at Wellcome, Laurie Taylor and a panel of experts explore the meaning of dirt, its relationship to order and how hygiene and the mass generation of dirt have become such potent symbols of civilisation. He is joined by the anthropologist Adam Kuper, the writer and cartoonist Martin Rowson and the historian Amanda Vickery to discuss dirt and why it provokes such fear, loathing and occasionally desire. Producer: Charlie Taylor.