Reading a medical dictionary, finding every disease
J. goes to the British Museum library to look up a minor ailment, reads the medical dictionary from A to Z, and concludes he has every disease listed except housemaid's knee. His doctor's prescription is a beefsteak, a pint of bitter every six hours, a ten-mile walk each morning, bed at eleven, and a ban on stuffing his head with things he does not understand. The episode shows how reading a list of symptoms, with no base rates to go on, can make a healthy reader convinced he is ill.