Do you eat rocks?  Well, maybe just one--what about salt?  Salt is so common you may not think about it much. This useful mineral is tasty on your fries (and everything else), and all animals need salt to keep their bodies working. But did you know that salt built the Great Wall of China?  Powered the Roman Empire?  Was the first refrigerator? Made Egyptian mummies? In this book you can find out everything you ever wanted to know about salt--what it is, how it’s made, and the ways salt has shaped history.  Make some popcorn, and dig in.