Yes, I read the history of salt. Sodium chloride, primarily. I was expecting more. The author did a reasonably good job of relaying the importance of salt throughout the ages, economically, militarily, and in terms of food supply, but there were many deficiencies also. Why salt isn’t as important today isn’t well explained. I was also frustrated by the number and length of recipes employing salt. There were several sections that were quite interesting (e.g. evolution of ketchup, origin of McIlhenny tabasco), but these curiosities were too few. Perhaps the history of phosphorus will turn out to be better.