Murder, magic and medicine. Part 1, The serpent's tail.

The first, of a new four part exploration of the role that animals play in a variety of medical treatments. Venomous snakes are known - and feared - for their power to kill. Yet they also have the power to heal, as many patients who have taken heart of circulatory drugs can testify. Dr O' Donnell discovers the extraordinary power of snake venom in nature, folklore and modern medicine.