The air around us is not just empty space; it is an integral part of the chemistry of life. Plants are made from carbon dioxide, nitrogen nourishes the soil and oxygen gives us the energy we need to keep our hearts pumping and our brains alive. This remarkable film reveals that how we came to realise this simple concept is a story that spans the entire history of science. It involves some of the most advanced technology of our modern age, but begins in a pre-scientific era when discoveries were