From anti-ague to anti-Alzheimer's agent: over the 112 years since it was first trademarked, Aspirin has evolved from popular painkiller to powerful preventative against heart attacks, strokes and even cancer. In this week's show we trace its history from the extraction of aspirin-like chemicals from willow bark to the creation of the drug itself. Plus, in the news, how the chemistry of life could have come to Earth in a meteorite and why we need to be careful with stem cells: a new study finds they have an above-average mutation rate. Also, a new technique to etch graphene sheets with... Like this podcast? Please help us by supporting the Naked Scientists)