salt

Salt is the main character and narrative anchor to this sprawling world history. Salt is a mineral and the only rock that we eat. While there are many different types of salts, the salt that figures most prominently in this book is table salt or sodium chloride. Humans and animals need salt to live and we even have a specific taste receptor to pick up salty flavors. On food, salt makes, in smaller quantities, the food taste better, while in larger quantities, the flavor of salt itself is appealing. Salt also has the property of preserving meats when salt is concentrated in the meat at appropriate levels. Vegetables can also be preserved in a similar way by pickling.

Humans have been seeking out salt deposits and figuring out ways to mine salt since our early beginnings. Animals instinctively seek out salt and early humans followed their animals to...