Water

Part 1 We need water: can you imagine life without running water?; case history 1 - the River Thames; how water is treated in a modern sewage-works; the water cycle; the oxygen needs of some animals; case history 2 - the River Irwell. Part 2 Water for agriculture: case history 3 damming the Nile - has Egypt done the right thing?; plants and water; some experiments on plants and water. Part 3 Water for washing: what is soap? how does it work; detergents; hard and soft water; case history 4 - Lake Erie, a matter of death and life; soap or detergent - which is better?; construct a model water-softener; make a bar of soap; experiments on soaps and detergents. Part 4 The boundless sea: case history 5 - a drop in the ocean; ways of cleaning oil-soaked feathers.