History of salt

However, salt was often difficult to obtain, so it was a highly valued trade item, and was considered a form of currency by many societies, including Rome.

According to Pliny the Elder, Roman soldiers were paid in salt, from which the word salary is derived, although this is disputed by historians.

Rock salt occurs in vast beds of sedimentary evaporite minerals that result from the drying up of enclosed lakes, playas, and seas.

Early Neolithic salt production, dating to approximately 6,000 BCE, has been identified at an excavation in Poiana Slatinei-Lunca, Romania.

Located in present-day Bulgaria, the town is thought by archaeologists to have accumulated wealth by supplying salt throughout the Balkans.

The Adriatic, having a higher salinity due to its shallow depth, had more productive solar ponds than the Tyrrhenian Sea, much closer to Rome.

[12] Salt in Chinese history was both a driver of technological development and a stable source of revenue for the imperial government.

The provinces subjected to the grande gabelle had to pay for salt at an official price and were also required to purchase a fixed amount annually, while in other areas, no taxes were paid at all.

This tax was particularly despised due to both the regional differences in its application and the disproportion between the value of the product, which in many places could be obtained almost for free, and the amount demanded for it.

In the Revolutionary War, Loyalists intercepted Patriot salt shipments in an attempt to interfere with their ability to preserve food.

[5] Before Lewis and Clark set out for the Louisiana Territory, President Jefferson in his address to Congress mentioned a mountain of salt, 180 miles long and 45 wide, supposed to lie near the Missouri River, which would have been of inconceivable value, as a reason for their expedition.

Monopolies over salt production and trade were essential aspects of government revenue in imperial China and retained its significance until 20th century.

This process takes advantage of the natural power of the sun to evaporate water, leaving behind concentrated brine that eventually crystallizes into salt.

This method is particularly appealing because it relies on renewable energy, making it an environmentally friendly and cost-effective way to harvest salt.

One of the most notable examples is the Guerrero Negro saltworks, located in the Ojo de Liebre coastal lagoon in Mulejé, Baja California, Mexico.

This saltworks is recognized as the largest in the world in both size and production capacity, producing millions of tons of salt annually.

It serves as a model of industrial-scale solar evaporation and plays a significant role in the global salt market.Other major salt-producing regions employing similar methods include the coastal areas of Australia and the Mediterranean coasts of France and Spain.

These locations share the necessary climatic conditions, such as abundant sunshine, minimal rainfall, and consistent wind patterns, which facilitate efficient evaporation.

The salt produced in these regions is used for a wide range of purposes, from culinary and industrial applications to de-icing roads in colder climates.

The earliest examples of this date back to prehistoric times and the pans were made of either a type of ceramic called briquetage, or lead.

[31][32] The earliest systematic exposition of the different kinds of salts, its uses, and the methods of its extraction was published in China around 2700 BCE.

The ancient Greeks continued this, and in 1753, English author and physician Richard Russell published The Uses of Sea Water in which he declared that salt was a "common defence against the corruption of…bodies" and "contribut[es] greatly to all cures".

Collected salt mounds
Naturally formed salt crystals
Ancient method of boiling brine into pure salt in China
The Sečovlje Saltworks on the Northern Adriatic Sea were probably started in Antiquity and were first mentioned in 804 in the document on Placitum of Riziano .
Vertical derricks and drilling rig from Qing dynasty Zigong , China extracting brine from deep underground wells.
Salt production on Læsø , Denmark (reconstruction)
Salt evaporation pond in Manaure, La Guajira, Colombia
Salt evaporation pond in Manaure, La Guajira , Colombia
A 'zouthuisje', i.e. little salt-house, used for salt making today. Many of these structures can be found near Twekkelo in Twente , the Netherlands .