Crystals as precious as gold
Salt is a mineral raw material that is no longer seen as the vital commodity it has been for millennia, from prehistoric times to the modern period. The consumption of salt is not essentially limited to cooking salt. If we look at the quantities of salt used up until modern refrigeration and freezing technology became widespread, salt was first used as a food preservative. And if we take into account the quantities consumed, it was primarily as a feed for livestock that salt was absorbed.
The history of salt overturns many preconceived ideas about the use of this raw material, which has been exploited and distributed over long distances in Europe since at least the Neolithic period. The earliest archaeological evidence of salt production dates back to the 4th millennium BC, when it was first documented in Poland.
Salt was therefore a vital product for ancient societies, and it is easy to understand why it was referred to in ancient times as "white gold". Because whoever produces and distributes salt actually controls the communities that depend on it. The archaeology of salt therefore plays a significant role in the economic, social and political history of past civilisations.
Who needs salt?
Human physiological requirements for salt range from a minimum of 4 to 6 grams a day to a maximum of 15 to 20 grams a day. Some of the salt required for human survival can be found directly in certain foods. However, it is insufficient and must be supplemented artificially, something that became even more important when mankind abandoned its nomadic lifestyle and began to develop a diet low in meat.
Salt is also essential for livestock, particularly herbivores: "Nothing stimulates the appetite of sheep, cattle and beasts of burden better than salt," wrote the Roman scholar Pliny the Elder. "Their milk is more plentiful and even their cheese is of a higher quality." Animals that are fed salt eat better and are healthier. Sheep produce more wool, of a finer quality, while cows produce more milk.
Animals need greater quantities of salt than humans. Sheep and small ruminants consume between 3 and 10 grams a day (slightly less than humans) and cattle between 10 and 25 grams a day. However, a dairy cow at peak production needs a total of around 80 grams a day.
