Book excerpt: From cooking to medicine, from engineering to art, chemistry—the science of molecules—is everywhere. A celebration of the molecules of chemistry, Every Molecule Tells a Story celebrates the molecules responsible for the experiences of everyday life: the air we breathe; the water we drink; the chemicals that fuel our living; the steroids that give us sex; the colours of the seasons; the drugs that heal us; and the scented molecules that enrich our diet and our encounters with each other. You can’t see them, but you know that they are there. Unveiling the structures of poisonous "natural" substances and beneficial man-made molecules, this book brushes away any preconceived notions about chemistry to demonstrate why and how molecules matter.