I want you to know about this thorough and well written book. However, unless you are writing a research paper on this subject matter, I’d suggest something a bit less comprehensive. The book details how we depended on salt for survival (preserving meats) until technical advances allowed for refrigeration. The value of salt “salary” comes from the word “salt”. The countries that exploited the land and people through the trade. The scientific discoveries. Finally, the evolution of salt to a plentiful commodity. It seems like the content of his books overlap a bit (Milk and Cod) Perhaps a bit less data about subject matter covered in other books.