Our body needs salt. In Ancient Rome a part of the wages of the soldiers was paid in salt. Thus, the word salary derives from the Latin sal: salt. This is also recognized in salami, saucisse, sausage, sauce and salad.
We use salt to give flavor and preserve food.

Salt: gives a bad taste to the food if you forget to sprinkle on it.’

Through sweating and urination you lose a lot of salt. You need about 6 grams per day. In Belgium we consume in our diet 4.5 times more! A deficiency causes muscle cramps, fatigue and nausea.

On food labels salt is also called sodium (+chloride).Salt is made up of 40% sodium and 60% chloride.

The Dietary Guidelines for Americans recommend limiting sodium to less than 2,300 mg a day — or 1,500 mg if you're + 51, or black, or have high blood pressure, diabetes or chronic kidney disease.

The average American gets about 3,400 mg of sodium a day.

Salt is found naturally in the soil as rock salt in places where inland seas have dried up long ago.
It is mined from a salt mine, or by solving it with long water pipes, and then pump up the brine to evaporate it back to the salt.

The early Celtic settlement that gave her name to the Hallstatt culture (800 -. 450 BC, near Saltzburg, Austria) owes its wealth to the extraction of salt, which was so valuable that it could be used as a universal currency across Europe. In several of their rich graves are found two and four-wheeled vehicles, even with iron suspension. Salt made them rich and powerful.

Sea salt is extracted by letting the sea flowing over the country in large shallow baking. The heat of the sun evaporates the water and the salt remains.
Seawater contains 30 to 40 grams of salt per liter. If the oceans evaporate, then three quarters of the earth's surface is covered with a 75 meter thick layer of salt.

From seawater
zoutpannenAs early as the prehistoric was at our coastals salt processed. Evidence of this are the huge amounts ‘briquetages’ along the Nord Sea. Seawater was after concentration in shallow pools cooked in bowls or jars of coarse pottery. The white gold sat solid fixed on the pot, which later was broken to sell the harvest. (Hence the many finds.) Above the fire was a grille made ​​of clay. (e.g. around a stick kneaded clay.) In this grid, the jars with brine were placed over the fire. Both the bars and the pots are called briquetage.
Later the Romans introduce an iron salt pan, so there was no more (lose) clay needed.

From peat ash
Moer or darink (also darg or derrie) are Dutch names for salt soaked peat, for years with seawater saturated peat. For selnering in the salt works the peat was digged and harvested, dried in airy piles and burned. The ash (zel: salted ash) was boiled with sea-water in order to produce salt (between 700 and 1500). The ash sinks after stirring to the bottom (zel ash). The first undesirable (lime) salts were scoured. Impurities in the brine were catched with eggshells that adhere them, and white of egg to create additional froth that was skimmed from the surface.

In the pan caked calcium salt was sold as a lick for cattle.

Zealand and especially Zierikzee became rich with it. The excavation increased the risk of dike failure (Reimerswaal) and was banned by the year 1500. The impact of the giant salt works was so big that they changed the entire coastline and relief. Dried peat is also used as fuel.

Salt can be used to provide food flavor or to preserve better. When pickling salt causes to withdrawn water to the product (fish or meat).

The Romans cooked several of their dishes in sea water (sometimes with extra salt!). In 2011, a company marketed(purified) Zealand seawater to cook mussels. You'll have to come up with the idea.

‘Regarding bathers is understanding why the sea recedes twice every day.’(Gaston Durlez)