4: The Amiable Juice. This week, Jonathan Miller traces the development of the National Blood Service. From on-the-spot transfusions for blitz victims to the development of blood banks, our ability to fractionate blood into its components was revolutionised by the introduction of plastic bags in the mid-seventies. But blood donation also has a symbolic dimension: it is a "gift relationship" which confirms our social solidarity. As society becomes more individualised, could our increasing reluctance to give blood reflect our loss of a sense of community? Producer John Watkins Repeated 9.30pm