On an August evening in 1928 May Donoghue, a shop assistant, entered a caf in Paisley. The circumstances of her visit made legal history. A ginger beer was ordered for Mrs Donoghue who famously complained that, to her surprise and shock, a decomposed snail had tumbled from the bottle into her glass. Mrs Donoghue sued for the nervous shock she claimed to have suffered as a result. The question whether she had a case in law against the manufacturer...