Some of you may know that David was involved in discovering that a girl who died after swimming in hot spring water in Bath had died from an amoebic infection. This resulted in the closure of the baths & a major archeological excavation. He appeared in a BBC documentary on this, and a couple of days ago I finally found the name and even a copy on YouTube - it was Chronicle in 1980. The YouTube copy is reasonable quality apart from the music, which sounds terrible: https://www.youtube.com/watch?v=Unbc7Z9mwjQ