Salt is a meandering popular history through that most commonplace of kitchen aids, salt. Since earliest human history, salt has been valued as a key nutrient, preservative, and enhancer of flavor. A ready supply of salt was at the bottom of ancient military strength, as an army marched on salted provisions.

Salt can be gathered off the ground from dry lake beds, mined from subterranean deposits, or gathered in certain ocean marshes. Along sunny shores, evaporation ponds can hasten the process, while in northern and inland locations, salt must be boiled from brine, a labor and fuel intensive process.

As a popular history, this book plods through the centuries, and mostly discusses Europe, though sophisticated ancient Chinese saltworks get an appreciative nod. Recipes for salted cuisine add human interest. Unfortunately, the book peters out in the industrial era, with a cursory description of modern vacuum distillation boiling and the rise of Big Salt, most famously Morton's brand in the USA. The book is comprehensive and frequently interesting, yet also the very definition of trivial. The closest thing to a thesis are sections on the use of state monopolies of salt as the basis of economic and military power.