Salt has always been an essential compound, both for human survival and advancement. Our bodies need it to maintain electrolyte balance, towns were built specifically to earn a profit from nearby salt sources, and its value has led to wars and restrictions worldwide. When it was used as a food-preserving resource, its value gained it the title “white gold.” This necessity has ensured its role in our history.
Salt is produced by three different methods. The first is by evaporating seawater. This is the most common method and is done by solar energy in tropical coastal regions. This was a time-consuming but low cost process. The second method was boiling down solutions from underground brine springs. This produced a much more concentrated and pure salt but at a higher price. The final method was mining rock salt from the ground. Towns were built up around these mine shafts and then funded by the profits they produced. This economic growth was essential to the survival of these young European towns in the Iron Age.
Salt’s structure is what gives it its usefulness despite its relative simplicity. NaCl is composed of a crystal lattice of two ions. These are the negatively charged chloride ions and the positively charged sodium ions. So it could, more specifically, be written as Na+ Cl-. The attractive forces between the positive and negative forces are what holds salt together. This provides a perfect preserving compound. Water molecules are partially charged. The hydrogen side is partially positive while the oxygen side is slightly negative. Therefore, these molecules can attach themselves to and surround the ions in NaCl (negative end to Na and positive end to Cl) which leads to the dissolving of the salt in water once the disconnected ions are completely surrounded by the solvent. Although the major characteristic of salt that causes solubility is its tendency to disperse randomly, this is how the process completes itself and the reason for the attraction between salt and water. The salt pulls the water out of the tissue of fish and other meats. This dehydrated habitat with a very high salt content creates a hostile and uninhabitable home for the bacteria that cause decay in our foods – the original use of sodium chloride.
Sodium chloride also fulfills a vital role for our bodies’ cellular system. The salt ions maintain the electrolyte balance between the cytoplasm surrounding the cell and the actual cell itself. Sodium ions are also forced out of the cell at a rate that surpasses the positive ions being introduced into the same cell. This creates a net negative charge within the cell in comparison with the outside of the cell. This difference powers the electrical impulses created and utilized by our nervous and muscle systems. This is only the beginning of the tasks that salt takes on inside of each one of us. The list goes on and on, but even if this was all it did for us, it would still be absolutely essential.
Outside of individual bodies, salt has empowered substantial events throughout human history. Economically, salt has always been a contributing factor in the trade agreements between civilizations going back to ancient Egyptians. In Africa, the trading of salt from the Sahara Desert built small trading camps into cities that stand to this day, such as Timbuktu. Timbuktu became a center of a trade triangle involving both Africa and Europe with salt, gold, slaves, and ivory being some of the main merchandise. Meanwhile, Timbuktu was also a center of Islamic education. In this way, it may boast of being a significant piece in the spread of the Islamic faith to the west coast of Africa. In Europe, the Saharan salt allowed fishermen to stay out at sea much longer and therefore bring in a larger catch in a shorter amount of time as the men could now salt and store the fish for long period of times in the hull of the ship without risking decay. This efficiency worked wonders for the economic stability of fishing towns.
The fact that every individual needs salt to survive has presented a great opportunity to governments for centuries. Through taxation of the product, they are able to secure a reliable profit from their citizens. However, sometimes the temptation is too much. When these tax rates have become obsessively high, they have caused trouble worldwide. This began with greedy tax collectors in Rome who escalated the tax to put more money in their own pockets. It was also true in France in the Middle Ages with the introduction of the gabelle. This tax was imposed originally on many products, but eventually it referred only to the tax on salt. With this tax, came a required purchase of a specified amount of salt at a price set and mandated by the king alone. In order to escape this, peasants began to smuggle salt like narcotics, an act that often resulted in hanging once one was caught in the act. This cruel act is often suggested to be one of the main grievances that led up to the French Revolution. Despite a few brief lapses, this tax lived on until after World War II. Salt was also a sore subject in British-controlled India. Here, the development of salt was completely forbidden, despite the presence of salt sources. The residents were forced to import heavily-taxed loads from Britain and this led to outbursts as well.
This chapter speaks of a molecule that was, and still is, an absolute necessity. This potency, as Napoleon’s Buttons suggests, is what allowed it such a huge role in human history and development. However, today its impact has significantly ebbed. The introduction of refrigeration meant the demise of sodium chloride as a food preserving compound because refrigerants are much more reliable and efficient. Now, its purpose is to be utilized as a starting material in the production of other compounds and to flavor food rather than to prevent its decay. This decrease in demand led to a major decrease in price and brings us to a place where salt is a common item on any dinner table. This is a far fall for a compound that, at one time, was as valued and sought after as gold.
Concerning sodium chloride, I fully agree with Le Couteur and Burreson as to its significance. You cannot deny what both the molecule and the search for the molecule has meant to mankind. Men have been imprisoned for smuggling it. It has financed governments, while oppressing citizens. Salt has built cities that thrived on the fruit of halite mines. The fishing industry was improved ten fold with the introduction of fish salting techniques. All of these factors exalt a molecule whose chemical structure and its uses has cemented its place in our history.