This book is everything you'd expect a book on salt to be.
OK, that is probably a little harsh, the book started out with an introduction that had a lot of very interesting anecdotal stories about salt and its role in human history. And this is no small role either. Hunter-gatherers got it from the meat they ate, but once people moved to agriculture they had to find salt to supplement their diets. Those not near an ocean or sea had to mine for it and the Chinese created many great inventions to mine salt long before Western society did. Of course, another well known use of salt is food preservation before refrigeration was invented. Although common today, salt was once scarce and cultures rose and fell over it and wars were fought for it. In some societies salt has been used as a currency, and many governments have taken to taxing salt. In fact, it was a slat tax that led Ghandi to do his march to the sea with, in the end, thousands of followers to break British law and collect their own salt. This led to many arrests, but eventually a treaty and later Indian independence. At the beginning the author did a great job of pointing out the limitation of salt's role in the course of history, but at the book progressed it got to the point where salt seemed to be the culprit of most of the world's major events. I think most books that have such a narrowly focused topic end up falling in the trap to some degree or another.
Despite being filled with many gripping stories like this, the book had a lot of in between time where it moved very slowly. The book was at some times repetitive, or the tales were so similar their were hard to distinguish. Also, once the introductory parts were over, there were many, many recipes for salt preservation and for pickling foods. They were woven into the story line, but not very practical since often the language was dated or the ingredients unfamiliar. One other thing that really bugged me was that although in general the chapters were chronological, the story lines from one chapter to another often overlapped time periods and there was frequent backtracking in time. Finally, the book ended kind of abruptly and didn't get wrapped up all that well, probably because so many of the stories were anecdotal.
I originally heard about this book somewhere on NPR and although the book is not focused on the science of salt, to my disappointment, there was a very good chapter (#19) on the chemistry of salt. I heard him say on whatever interview I heard of him, that the book was not scientific, and I even caught a couple of minor science errors, but the science he included was good and interesting, and is also what paved the way to salt being common.
The last point that I'll make is a fact towards the end that stood out to me. Once the fish of the sea were abundant, but salt to preserve them was limited; now due to over fishing and poor conservation the salt is abundant and the fish are lacking. It is a sad truth that many in this age deny, but we have an impact on our environment and we should be responsible to manage it well. I have not read any of Kurlansky's other books, but he has done a few others on fish and food if you're inclined to learn more.