Common salt which is consumed in different food items is a naturally occurring mineral composed primarily of sodium chloride (NaCl). Salt in its natural form as a crystalline mineral is known as rock salt or halite and also is present in vast quantities in sea water, where it is the main mineral constituent. The ocean has about 35 grams of salt per litre, thus providing a salinity of 3.5%. Salt is indispensable for animal life and saltiness is one of the basic human tastes. The tissues of animals contain larger quantities of salt than do plant tissues; therefore the typical diets of nomads who subsist on their flocks and herds require little or no added salt, but cereal-based diets consumed by the modern man require supplementation with external salt. Salt is one of the oldest and most ubiquitous of food seasonings, and salting is an important method of food preservation.
History: Some of the earliest evidence of salt processing dates to around 8,000 years....
