THE FIRST OF THE SALT MEN on record was found in 1573. He was bearded and fully clothed in a woollen jacket and trousers, leather shoes, and a conical cap. His flesh was yellow and hard as a rock, but perfectly preserved because he was buried in salt. After the people of the village had had a good look at him, spread out in church “like a salted codfish,” he was given a Christian burial in the mountain, “to get him out of men’s thoughts.” At least three other bodies in a similar state have been found in the shafts of salt-mines in the same region near Salzburg (Salt Town), Austria. They were all victims of mine accidents between two and three thousand years ago.
In 1836 a cemetery dating back to the age of the Salt Men was found in the vicinity of the nearby village of Hallstatt (which also means Salt Town). So far, well over two thousand graves have been excavated at this site, many of them royal burials equipped with gold jewellery, chariots, iron weapons, and joints of salt beef for the journey to the other world. Tiny Hallstatt has given its name to a whole civilization whose confines stretched from Spain to Yugoslavia during the First Millennium BC. These were the early Celts, who made the transition from the Bronze to the Iron Age in Europe. Hallstatt princes could import the finest art works from ancient Greece. They traded with the Etruscans, the Egyptians, and the Romans, and their merchant subjects continually travelled back and forth for distances as great as that between southern France and Cornwall.
Neither the riches nor the travel would have been possible without these people’s knowledge of salt deposits, salt mining, and the properties of salt. Hallstatt miners knew exactly how and at what angle best to sink a shaft through surface layers of soil to the richest salt seams in the mountains. As they walked down into the tunnel they had made, they would grip their “lamps” in their teeth: long pine sticks soaked in resin and lighted at the end. Down below, roped bunches of burning pine lit the work-face. Remains of these torches have been found, together with many miners’ tools, the goatskin sacks they strapped to their backs for hauling back precious lumps of salt, wooden buckets, water bags—even a Wagnerian-looking musical instrument made of horn, used, perhaps, to signal a miner’s whereabouts in case of mishap.
These Iron-Age men used old-fashioned bronze in the mines, for they had found out that bronze resists salt corrosion better than iron does. They were prepared to live and work high in the cold and dangerous mountains in order to get salt, even though contemporary settlements are almost invariably to be found in sheltered valleys. The miners knew how and where to find salt, and this gave the Hallstatt Celts an endlessly useful headstart in trading relations with other people less fortunate, less energetic, or less informed than themselves.
“God has distributed His benefits in such a manner that there is no area on the earth so rich that it does not lack all sorts of goods,” wrote the French political theorist Jean Bodin in 1568. “It appears that God did this in order to induce all the subjects of His Republic to entertain friendly relations with one another.” For many thousands of years human beings have longed for salt. Until one hundred years ago, salt was to be had only from great distances; at the cost of long, skilled, and watchful labour; or with the aid of enormous courage and technological expertise. Salt has forced man to explore, to think, to work, to travel. To obtain salt he has erected whole political and economic systems; he has fought, built, destroyed, extorted, and haggled.
Like corn, salt has received the full blast of modern man’s scientific attention, but until recently salt has been available only in relatively tiny amounts: its historic importance has been a direct function of its rarity. Salt has never been thought of as motherly or bountiful like maize. On the contrary, its mythical character is habitually dry and sterile. Salt is clever and sly and hard to get; a little of it goes a very long way. It is a thing of fate and malediction, both necessary and absolutely irreplaceable.
In the earliest times, men usually let animals find salt for them. An outcrop of rock salt was called a salt-“lick” because animals went there to lick it. When the Europeans came to North America they did not find it trackless, for buffalo trails had been worn for centuries to the salt-licks, and it was along these smoothed short-cuts through and round natural obstacles that the first explorers began to move across the continent. Amazingly early in human history, men began to dig into the earth to find salt. All over the world, people like the Hallstatt miners have tunnelled along salt seams, braving floods, the collapse of roofs and walls, exhaustion, salt-burn, suffocation, and accidents with their light-source, fire.
Modern salt-mining has become, in comparison, almost miraculously safe and productive. In many cases, mining engineers take advantage of what has always been considered one of the eeriest of the attributes of salt: the rock is not only edible but it also dissolves, and can be returned to its solid state again. Water is injected into the salt seams through tunnels bored from the surface; the brine is pumped out and then evaporated to produce salt again.
This method, like the digging of rock-salt mines, leaves empty spaces under the earth where the salt has been removed. A quarter of the city of Detroit, Michigan, stands over the hollow warrens of a salt mine. Gigantic glittering vaults, salt pillars, and passages can make awesome sites for tourists to visit today, and satisfy man’s ancient craving for caves and grottos in the earth. The salt mines of Wieliczka, near Krakow, Poland, are over a thousand years old. They contain huge toothed wheels, vast wooden staircases, and support structures worthy of the imagination of Piranesi. Dance halls have been installed in the mines;elaborate bas-reliefs in salt decorate the walls, and there are also chapels, with statues and altars carved in granite-grey sodium chloride. Part of the mine has become a hospital for sufferers from respiratory ailments because the temperature and the humidity in the vaults is ideal and constant. An old salt mine near Erivan in Soviet Armenia has also become a clinic: the sulfates and other microelements remaining in its salt walls are considered beneficial in the treatment of allergies.
For over a hundred and fifty years after the Europeans’ arrival in North America, their increasingly determined hunt for underground salt deposits was bedevilled by the irritating fact that a discovery of salt was very often accompanied by a gush of filthy black pitch. A salt-dome is a vast, seemingly bottomless, column of salt squeezed up from the earth’s depths, often “billowing” near the surface into a dome shape. In 1901, drilling at a salt-dome in Texas produced the largest spurt of the black stuff yet seen. But by this time scientists understood the properties of petroleum, and Spindletop, as the gusher was called, showed that it was possible to find oil in sufficient quantities to use it as fuel. So the petroleum industry was born. From this time onwards, the discovery of salt became precious as one useful pointer to the possible presence of oil-wells.
Most of the salt-domes in and around the Gulf of Mexico in the United States have now been explored and a good deal of their associated oil extracted. Many of the old salt-works, both there and elsewhere in the United States, are being used as storage facilities, for oil reserves mostly: old mines are hidden, easily guarded, and use no surface space. The Underground Vaults and Storage Company of Hutchinson, Kansas, owns an old salt-mine which it rents out as a depot to anyone who wants to use it. The survivors of a nuclear war will be able, if they can make their way to Hutchinson, Kansas, and get 200 metres (650 feet) down into the salt-shafts, to retrieve an assortment of objects which have been chosen partly with them in mind. There are seeds of hybrid plants, the files of various commercial enterprises, secret formulae for making brand-name products, food for the treasure-finders, and even folding cots, just in case they bring their babies with them. There is a film library which includes Gone with the Wind, Polly of the Circus, and lots of Buster Keaton.
A further use for salt-dome cavities has been suggested recently. Could we not use these spaces—deepened, or even especially created—to store the ever-mounting quantities of nuclear waste which our energy-hungry age keeps producing? Nuclear waste (which is at present being, we hope temporarily, stored in steel and concrete tanks) can remain a radioactive threat for ten thousand years; perhaps we could safely bury it in a salt-dome, fill the cavity up with salt, and somehow keep memory of the spot green for thousands of years, so that no one in future ages will accidentally find their way into a lethal waste-dump. Salt beds have the advantage of dryness, and tend not to be present in earthquake-prone areas.
The idea has been seriously considered. One snag is a recent finding that gamma radiation and heat from waste canisters creates corrosive acid in salt, and this in turn attacks the protective packaging and increases radiation leakage. American government regulations say that the packaging around nuclear waste must remain intact for three hundred to a thousand of the ten thousand dangerous years, so (for the moment) the idea is in limbo. There is also, unfortunately, a danger of water leaking into a salt dome: in November 1980 a good deal of a lake drained away into the shaft of a salt mine under Jefferson Island, Louisiana, when an oil drill punctured it by mistake. Even keeping reserves of petroleum in salt cavities is dangerous: in 1980, for instance, the population of a small town in Texas fled as fumes began to leak out of the ground. The town was built over a salt-dome which was being used for storing oil and natural gas products.
Salt is an edible rock—a contradiction in terms. Not only is it mined, but it is also harvested—and this is another of the ways in which salt slips out of our net of categories, which customarily pits Hunters and Gatherers against Agriculturists, and Miners (industrial workers) against Peasants. Those who make gardens in order to win salt from the sea must prepare their land with intimate knowledge of its position and properties, watch the climate with unceasing vigilance, wait for the crop, remove obstacles in the way of its growth, and bring it in at precisely the right moment. They must have the shrewdness, the know-how, and the patience of farmers, and must run many of the same risks.
A salt garden is a chequerboard of wide shallow basins or “saltings” created at a place which the sea tide covers in a manageable measure. Incoming sea water has to be shut out when the ponds contain exactly the right amount of water. They must be kept clean and whole, and the sea water has to be guided where it ought to go, from basin to basin as the sun evaporates it to a thickly concentrated “pickle” or “mother-liquor” from which the salt will crystallize out. Passage through lime ponds for the deposition of calcium sulfate is followed by more draining, waiting, washing, storing, and cleaning of salt-ponds so that the process can begin again.
Rain is a grave set-back for a salt garden: the ponds should, if possible, be covered before rain comes, and rainwater must be carefully skimmed off if it falls onto the carefully acquired brine concentrations. Sun is needed—a great deal of it. Salt, said Pythagoras, is born of the purest of parents: the sun and the sea. The end-product of this process is known to the trade as solar salt. This, probably the oldest of salt-winning techniques, is the one often preferred where salt is used in religious observance. Ecologically, the solar method is by far the least damaging way of winning salt, but it takes time and human labour, and so the practice is gradually dying out.
Salt is an exceptionally heavy commodity; in the past, people who lived far from the sea or a salt mine, or on a coast with not enough sunshine, had to pay high transport costs or find other ways to get salt. They might burn plants which contained salt, or char brine-soaked wood and sprinkle the black ash or the powdered burnt wood over their food. They might leach salt-impregnated peat or sea sand, or, in very cold climates, concentrate brines by removing ice from them. A very early method was briquetage. Clay cups of brine were fired until the water evaporated and the salt hardened; the clay was then broken off and discarded. Many archaeological sites, from the Second Millennium BC to quite recent times, are laden with the débris of briquetage.
When Julius Caesar arrived in Britain he was disgusted to find the natives of Cheshire flinging heated stones into the brine of their salt springs, and scraping off the resultant salt crusts. He sent for “salinators” from Rome, and these men taught the Britons to boil their brine in shallow lead pans over fires—a method which slowly improved, survived, and is still used today.
If brine is swiftly boiled it produces cubic salt crystals; if it is gently heated just enough for surface evaporation to take place the crystals are pyramidal, and to the naked eye look flaky rather than granular. Surface-evaporated salt, as opposed to salt evaporated mechanically and chemically from the brine, is called “grainer” salt in North America, and has survived as a specialty product: it is close enough to the pure solar salt to be accepted as kosher by Orthodox Jews. It is also highly sought after by gastronomes, because it is not treated with additives. “Unrefined,” in the perversity of modern language and practice, has come to be synonymous with “pure.”
Most salt used for culinary purposes today is the result of evaporation of brines by means of sophisticated heating machines. The first multiple-effect salt evaporator was built in the United States in 1899. The salt is separated from the brine, heated, cleaned, spun and sucked dry, then mechanically packed and labelled. The process is fast, and the salt is fine-grained and extremely free from impurities. Unprocessed sea salt, on the other hand, is grey, with coarse and irregular grains, and often damp. It is loaded with calcium and magnesium chlorides which deliquesce and give a slightly bitter, faster, and sharper taste sensation which is much prized by gourmets.
Salt is hygroscopic: it attracts moisture. This is why the holes in salt shakers can clog up in damp weather. In the past most salt was served frankly damp in a dish, and it was taken with the fingers or in a spoon. Erasmus said it was very impolite to take it with a knife which had not been cleaned off first on a hunk of bread. But people would much rather it ran free, so that “When it rains, it pours,” which is the (justified) claim of one of the most successful advertising slogans ever devised, that for Morton’s Salt (1910). For this reason salt grains are marketed with a coating of chemicals to keep them separate. A tiny percentage of potassium iodide is also added in areas such as the Swiss Alps and the North American Great Lakes region, where there is a deficiency of iodine in the soil and therefore in people’s diet. Iodine deficiency leads to goitre, a swelling of the thyroid glands at the base of the throat. The iodide is accompanied by a stabilizing mixture of sodium thiosulfate and calcium hydrate. To sensitive palates, the result of all the subtractions and additives is a condiment depleted in complexity as well as in sheer salty taste.
The arts of salt-winning are various, and they are all ancient. Even modern heating machines serve merely to evaporate, which is a variant on the old solar or salt-boiling method. Japan is today the only major industrialized country which has no underground salt beds in its territory, although Scandinavia is also chronically short of salt. The lack is serious, and only partly alleviated by solar salt gardens, which are annoyingly slow for modern industrialists. Brine-boiling uses enormous amounts of fuel, which the Japanese do not have. Instead they have come up with the first really new idea for retrieving salt since prehistory. This is electro-dialysis; sea water is concentrated into brine by means of electrically charged membranes. These collect and separate the positively and negatively charged ions of sodium and chloride, the components of common salt; the salt-cleared water is then drained away from the concentrated brine. The method has been in successful operation, both to obtain salt and to desalinate sea water, since 1965.
Most people sitting down to a meal such as the one we are considering will reach for the salt-cellar, knowing that its contents can enhance the taste of the corn, the rice, the lettuce, and probably the chicken as well. Those of us who seem to want more salt than others do were especially relieved to be told recently that salt is not really as dangerous as we had been led to believe. For some years we had been loudly exhorted to curb our appetite for salt and even to cut out salt altogether, because it raised our blood pressures and caused us to retain fluids. Which of these claims is true?
The fact is that our desire for salt is little understood; so is our need for it, and so is the reason for the saltiness of our bodies. It is usually thought that we are salty—our blood, our sweat, our tears, our urine, our saliva (the word derives from sal, Latin for “salt”), are salty—because life began in the sea. We are walking marine environments, and the appeal of the taste of salt for us is in our natures.
Consuming salt nevertheless makes us thirsty. It has only recently been established that the hypothalamus at the base of the brain is what arouses our desire to drink. This organ measures the concentrations of sodium and potassium ions in our body’s fluids, and when these become too high because of a loss of water, or if we take in an excess of sodium as a component of salt, we feel thirst.
Sodium and chloride ions have electrical charges which enable them to carry current: together they keep the liquids in our cells and their surroundings in balance, drawing water molecules through membranes when necessary to hold them in steady quantities. If blood cells were surrounded by a saltless liquid, water would seep into them through the membranes and they would burst. The amount of salt itself in the body is governed by many co-ordinated mechanisms: the kidneys, for instance, which get rid of excess salt through urination; and sweat which throws off varying amounts of salt, whatever will suffice to keep the balance.
A sufficient salt intake for a normal human being is between 1.1 and 3.3 grams a day. But the average European or American customarily eats as much as ten times that amount; we leave it to our bodies to deal with the overdose. When “modern” diseases make us worried and we look round for a “modern” cause, salt is easily pounced upon as the culprit. Hypertension, and consequent heart and kidney disease and stroke, have recently been blamed on salt: there must, we feel, be a cost for our grossly excessive behaviour. Now scientists are saying that merely cutting back on salt is far too simplistic a solution to hypertension, and that eating too little calcium or potassium is just as likely to be harmful to the body. And yet salted foods like cheese (which provides both calcium and potassium) are often just the things people do without when they give up salt.
Why is the earth full of salt? We now know that it is full of salt, in spite of the apparent rarity of the substance which has tantalized mankind for so many thousands of years. Almost every country on earth possesses vast resources of underground salt in seams and domes and layers often hundreds of metres thick and hundreds of kilometres in extent. Where did it come from? Many scientists have believed that it came from the sea. In eons of geological time, oceans have spread then evaporated, and the salt they left has been folded and rolled, squeezed and kneaded deep into the earth, or extruded above it as salt mountains and salt glaciers.
Where did the sea get its salt then?
The sea varies in its salinity, but is, on average, 3.5 per cent salt; that is enough salt, if it were powdered, to cover the whole earth thirty-six centimetres (14 ins.) deep. Aristotle’s explanation for the presence of salt was the opposite of the one mentioned previously: the sea, he thought, began as fresh water, but became salty from rain and rivers washing salt into it from the earth. Even allowing for the fact that the sea is constantly depositing some of its salt on the land, this would mean that the sea would get saltier all the time, and we now know, from the evidence of tiny pools of sea-water trapped in sedimentary rock, that the salinity of the oceans has not increased since at least Cambrian times; it was if anything greater then. And the fossils of marine life in those rocks are similar to the creatures living in the sea today; their environment must, therefore, have been not unlike our ocean. Moreover, rock salt does not contain marine fossils, and this throws doubt upon its oceanic origin.
Another of salt’s mysteries is this: if our bodies need so little, why do we crave it so much? Unlike the human “sweet tooth,” our salt hunger is shared by animals: cows, for instance, love salt, and will lick a hole in a wall they find pleasantly salty. Our tongues are well supplied with salt-tasting buds, and to compound our frailty, saltiness enhances the taste of sweet things and disguises bitterness. It also helps make stale or spoiled food edible.
But many peoples have simply never known that salt existed and have lived perfectly healthy lives without it. Australian aborigines and American Indians and Inuit often knew no salt. Early human settlements were apparently not built to be near salt-springs. Human beings, it seems, learn about salt (and become addicted to it) at a very precise moment in their history: when they cease being almost exclusively carnivorous and learn to eat vegetables in quantities usually available only when they grow them themselves. When people begin not only to eat a lot of vegetables, but to reduce the salt content in their food by boiling it—a cooking method which presupposes the ability to make metal pots that can be set directly over a fire—then salt becomes more desirable still.
Carnivorous animals and meat-hunting men find enough salt in blood to satisfy them. Certain African tribes who have never been able to assure themselves of a salt supply, prick the necks of their living cattle and drink their blood. There is no immediate need to slaughter a cow for meat since, alive, she is a sort of walking larder, providing protein and salt.
It is herbivorous animals that love salt. One theory about the origin of the domestication of cattle by man is inspired by the “salt tie” which still operates between reindeer herders and their animals. Cattle may originally have been taught when very young that they could get their salt from men. They would then range freely in search of pasture. Their “owners” needed only to visit them occasionally in the field with gifts of salt to remind them that they were no longer wild. Men could then proceed to take advantage of the relationship.
Salt, in myths all over the world, is seen as a “newcomer,” an addition whose necessity is not perceived before it arrives, but which is intensely attractive, indeed irresistible, once it is tried. Here, for example, is a North American Indian myth about the presence of a salt-lick near the home of the Indian who told it:
Salt used to be far away. He was a man and was travelling through the country. The Indians never used salt then. He looked ugly all over, and the people did not like him. He came to a camp and said, “Let me put my hand in there, then the food will taste well.”
“No,” said the cook, “I want to eat this, you look too ugly.”
He went off to another band and said, “Let me put my hand in here, it will taste well.”
“No, your hand is too dirty.”
He came to another band and said the same thing, but people declined his offer. At last he came to a single man, and he was a cook. He said, “I want to put my hand into the food, then it will taste better.” And the cook allowed him to do so, and he put in his hand.
“Now taste it.” The Indian tasted it and it was good. Salt settled there and stayed forever, about ten or twelve miles from St. Thomas.
Notice in this story that people are suspicious about salt. For one thing, eating it is eating earth, and that in itself is peculiar behaviour. You add it to your food, it disappears, yet it indescribably alters the taste of everything you eat. Salt is weird, powerful, dangerous, and “extra.” In religious symbolism it is always linked with “strong,” powerful substances like iron or blood. We feel that a little of it is all we need, that this little has made all the difference, and that we ought not to abuse the privilege of having it. Furthermore, adding salt is being clever, and getting salt has always taxed human intelligence. By the same token we feel that we could easily be tricked by someone who cunningly adds salt without our knowing it, thus imparting a sinister attraction to something we ought not to want. When someone “salts” a mine he wishes to sell, he plants nuggets of gold in his worthless property for dupes to find.
All these ancient symbolic notes are struck in our modern, apparently “scientific” distrust of salt in our food. Our readiness to feel uneasy about the hand of processors in what we innocently buy and ingest is encouraged by revelations about the salt content of common packaged foods. We did not know until the alarm was raised recently that instant chocolate pudding has more salt in it than potato chips, that canned vegetables always receive a mechanically-supplied salt tablet (How large?) before the can is sealed, that tomato ketchup is a bottled battlefield for the forces of salt and sugar. Our response is to demand explanations, to insist on better labelling—and in many cases to switch to saltless food. And instantly the challenge is accepted by a business community alert to what it is that people will pay for. A whole new market has been created, where the sophisticated prestige of “No Salt Added” replaces the primitive seduction of hidden seasonings.
Salt is both “farmed” like wheat, and “searched for” like game or wild berries. Bread (grown, harvested, ground, leavened, and baked) and salt (found, won, collected and efficiently transported) together cover the field: they represent man as Farmer, patiently and wisely nurturing his crops, but also as Hunter, Scientist, Adventurer, and Organizer. Bread and salt are customarily offered in Russia (where the word for “hospitality” means literally “bread-salt”) and in other countries, as a sign of welcome to a guest: bread and salt symbolize the precious stores of the house, the fruits of the host’s labour, his patience, his ingenuity, his civilized foresight and preparedness.
Oath-taking, in many cultures, is a ceremony involving salt, just as the act of swearing may employ blood or iron as a sign denoting a person’s unbreakable word. Salt is shared at table, in a context of order and contentment. Traditional Bedouin will never fight a man with whom they have once eaten salt. When the Lord God of Israel made a covenant with the Jews, it was a Covenant of Salt, denoting an unalterable bond of friendship. It also meant that the Jews had settled down in the Promised Land, had ceased to be sheep-herding nomads, and would now eat the fruit of their harvests, cooked and seasoned with salt.
Soon after the Arabian camel reached Africa in the fourth century AD, the peoples of the Mediterranean found a way to reach a new world. Gold, the immortal metal of kings, was becoming ever scarcer in Europe and more prized. The Africans away to the south, beyond the Sahara, had plenty of gold, and apparently thought it nothing special. There was one thing they did want and could not find for themselves, and the Arabs and later the Europeans soon found out what it was. And so the salt caravans began to cross the desert to the salt deposits of Teghaza in northern Mali. From the eighth century onwards, the three to four thousand camels in each of these caravans were loaded up by their Moslem owners with copper pots, woven rugs and clothing, grains and dried fruit, all of which would later be exchanged for slabs of salt at Ouadane (Mauritania), Teghaza, and later Taoudeni (Mali). Then they plodded on, bearing their cargo of salt, to Timbuktu, a place whose whereabouts was kept secret from the infidels. Timbuktu gradually became to the European imagination a city of magnificence and mystery. Explorers dreamed of finding it for hundreds of years; the Frenchman René Caillié finally did in 1828—and was bitterly disappointed.
Timbuktu was a trading post founded by Tuareg nomads in about 1000 AD, on a branch of the Niger River. It has no gold, and no salt; it merely served as a stopping-place for the caravans, a place where guides could be found for the most secret part of the whole journey. Many days’ travelling out of Timbuktu a place was reached where the Mute Exchange with the mysterious Africans could begin. First the seller would beat drums to show he had arrived, leave a heap of salt-slabs out, and retire. In time the buyer would venture forward and leave gold, or ivory, or sometimes a slave, next to the salt, and then disappear. The seller looked over the offering and would leave without touching anything if he was not satisfied. His unseen client would then raise the offering or remove it. When the seller took the African’s offering he beat his drums again, and the deal was sealed: they never saw each other or exchanged a word.
When all the trading was done the caravan returned to the sea coast of Morocco. There the goods it carried (gold dust, ivory, slaves, and goat skins to be sold as “Morocco” leather) were shipped to the Near East and to Italy or Spain. The caravan journey had taken about six months. In this manner, from the eighth to the sixteenth centuries AD, Europe alone received six metric tons of African gold per year. The gold/salt trade finally ceased at the end of the nineteenth century, but to this day caravans from Taoudeni carry salt to Timbuktu.
The Danakil Depression in Ethiopia is a weird moonscape 193 kilometres (120 miles) long, covered with brilliantly coloured salt hills and chemically green warm lakes. It bubbles with sulphur springs, geysers, and volcanic activity. Five thousand Danakil nomads hold traditional rights to exploit the salt plain. They cut and load salt bricks in the boiling sun and live for the season in houses made of salt. An ancient trail still leads camels, donkeys, and mules many kilometres up into the hills for trade with the Ethiopian highlands and beyond. The salt they carry is used as money; it passes from hand to hand in exchange for other goods; it increases in value in proportion to its distance from the salt plain of Danakil. The Aksum Empire of Ethiopia traded this rich asset with Egyptians, Romans, Arabs, and Indians before the third century AD, but the exchange is certainly far older. The incredible exertions of all these people and animals, the intricate systems of relationship and value, and the vast distances travelled, are typical effects of the human desire for salt.
Salt towns have always been rich and busy places, and proud of their special status. The Greek word for salt is hals. Derivatives from this word often substitute s for h, which is why the Romans called it sal and we say “salt.” Salt names abound for western European towns, rivers, and hills, and these may be clues to the history of their occupation: Halle, Hallein, Reichenhall, Hallstatt; Alès, Alesia (the French drop their h’s); Salies, Salins, La Salle, Moselle, Salzburg, Salcott, Salsomaggiore. Salina was the original name of Syracuse, New York. Malaga is Phoenician for “salt.”
At least by the date of the Domesday Book, the Anglo-Saxon term wich meant “aplace where there is salt,” so we get Droitwich, Nantwich, Northwich, Sandwich. Sodom, in the neighbourhood of which Lot’s wife turned into a pillar of salt (petrification, turning into stone, is a common story-punishment for looking back when you shouldn’t—but then, salt is “rock”), was near to the Dead Sea and to numerous salt mines. Its name is probably a contraction of Sadeh Adorn, meaning “red field” or “field of blood.” The reason may be that when solar salt is evaporated from brine springs and lakes, the concentrate often turns bright red because of bacterial action.
Salt towns were often centres for the salting of meat (if inland) or of fish (by the sea), for salt was man’s most useful preservative: without it he would have suffered greatly during the winters. Until recently, unless a farmer had enough land to grow his own hay, he had no means of keeping his cattle alive during the cold months, and thus the feast of St. Martin, November 11, was the day on which farmers traditionally slaughtered their animals, salted the meat, and packed it in barrels to keep. On that day the innards, ground and enclosed in sausage-skins, were consumed in vast quantities, together with the first of the new wine. Martinmas was known as the Feast of Sausages and Black Puddings.Brined pork-in-the-barrel was a precious source of meat and fat for soups, garbures, sauerkrauts, and cassoulets through the winter. The pork-barrel was also to become a North American institution, together with “pork barrelling,” which meant doling out tasty morsels of jobs or patronage to one’s friends. Beef was often “corned,” or covered with large salt crystals. (The Old Norse word korn meant a grain-sized lump of anything.)
Ocean fish was salted as soon as it was caught. Fresh sea fish was not available to anyone who lived away from the coast until the arrival of modern transport and refrigeration. Salted foods were big business—so big that not even wars interrupted trade. The northern Protestant countries of Europe supplied a great deal of salted fish to the Catholic southern countries for consumption during Lent and the rest of the year, all through the sixteenth, seventeenth, and eighteenth centuries. But the north (where the fishing was excellent and efficient) needed solar salt from the warm south in order to send back their herring and haddock (both words may derive from hals, and mean “salted”), and cod. And the south—mainly the western coasts of France, Spain, and Portugal—supplied salt through all the long wars of those centuries, to the profit and satisfaction of everybody involved.
The chemistry of salt’s preservative action is still not completely explained. It prevents spoiling microbes from living where it is present, but, used in the correct amounts, it also promotes the growth of lactic acid bacteria, and this helps products like salted cabbage to ferment into sauerkraut. Salt penetrates moisture-filled meat, fish, or vegetables. It also causes blood and water to run out (in this role salt renders meat kosher in Jewish observance), and in sufficient quantities it will dry flesh and skin completely. Blood extraction and the prevention of decomposition make salt vital in the curing and tanning of leather—just as it was an important ingredient in the Egyptian recipe for mummification.
Its role in seasoning and food preservation made salt so necessary that people were willing to travel punishing distances to get it. But without salt, and its ability to keep food, long journeys would themselves have been impossible. People carried hard nutritious cheese and salted beef—dry, light, delicious, and edible without cooking—when they had to travel lightly and did not know where the next meal was available. Salting made food exportable. The fish of faraway Newfoundland was worth catching for consumption in Europe because, with a certain amount of careful organization, it could be salted.
From the end of the fifteenth century, Basque, French, Dutch, and English fishermen were hauling in Newfoundland cod, the most bountiful catch mankind has ever recorded. (From the sixteenth to the eighteenth centuries cod made up 60 per cent of all fish eaten in Europe.) Fishing fleets called in and loaded up with salt at Spanish and Portuguese ports before sailing across the Atlantic. Once caught, the fish was cut up, cleaned, and salted right in the fishing boats, which were filled to the brim with their load. This “green” cod was often dried as bacalao, either when the ship returned to Europe or at facilities set up on the Newfoundland coast itself. Some of the fish was taken to the Caribbean, where it fed slaves on cotton and sugar plantations. The boats, emptied first of their salt, then of their cod, now took molasses on board, and cotton and rum, for the journey back to Europe. Salt caused travel, used trade channels, and simultaneously facilitated both travel and trade. Caribbean people still have a taste for salt cod. And Portuguese fishing-boats still arrive in Newfoundland ports loaded with salt to preserve their cod-catch from the Grand Banks.
Salting food is now a relatively minor industry: Parma ham, brandade de morue, conserved goose have become gourmet treats where once they were peasants’ standbys. The modern method of keeping food is by refrigeration, which means that not only can we keep perishable goods, but we can supply them for sale far away from their place of origin. But salt has not been dislodged from its central role in the keeping and moving of food, for the freezing process itself depends on sodium chloride. Salt’s combined melting and temperature-lowering action upon ice and water has the effect of removing latent heat from adjacent substances. It is mixed with crushed ice in refrigerated railroad cars, and later in our meal we will see that it is used in the same way in the old-fashioned method of making ice-cream. In fact, ice itself is manufactured by salt brines, cooled through alternately compressed and expanded ammonia or other gases. Liquid sodium, one of the two main ingredients of common salt, is what is used to cool nuclear reactors.
Even the roads travelled on in cold climates depend these days upon salt to clear them of ice and snow and keep traffic moving. When salt is thrown onto snow, some salt dissolves and some ice melts to produce brine. Each salt grain melts a path downward through the ice for itself, forming brine on the way. When the brine hits the pavement it spreads out and melts the bond between the pavement surface and the ice over it, making it easy to break the ice and throw it aside.
Finally, as the Hallstatt miners knew, the presence of salt makes metals rust. Our cars are attacked by the salt laid down to clear a way for them, because salt increases the solubility and therefore the availability of the cause of corrosion, which is oxygen.
Salt was one of the first articles traded by man. Ever since the earliest pact was reached, many thousands of years ago, between people who had salt and people who had none, salt has been one of the most manipulated, most politicized substances on earth. The world’s oldest trade routes often had the principal aim of connecting salt resources to human habitations. One of these is the Via Solaria or Salt Road, which connected the saltings of the port of Ostia with Rome and the far Adriatic; it is one of the oldest roads in Italy. Salt has been sold in lumps, loaves, tablets, bricks, and grains. It has helped make the fortunes of towns, countries, and whole civilizations. The word “salary” dates from the Roman distribution of salt as part of their soldiers’ pay; an inadequate person, we still say, is “not worth their salt.” Marco Polo saw salt, moulded into cakes and stamped with the imperial seal of the Great Khan, used as money in Tibet.
Many wars have been waged over salt. Morocco fought Mali in the sixteenth century for the mines of Taoudeni; the Venetians, whose salt interests are an historical study in themselves, destroyed Comacchio in the tenth century and the salt gardens of Cervia in the fourteenth; pirates throughout the centuries ambushed and raided the slow heavy convoys of salt ships. Cortes and his Spaniards found important allies for their conquest of Mexico in the Tlaxcalan people, to whom they offered access to salt and cotton. The Tlaxcalans hated Montezuma and the Aztecs, says a sixteenth-century source, because “they ate no salt, since there was none in their country, nor were they allowed to buy it anywhere else, nor did they wear any cotton clothing. …” It was the Aztecs who kept these people from salt and from their favourite clothing material; even tyrannical foreigners seemed to them useful allies against their oppressive neighbours.
One of the ways in which governments have made themselves useful is in assuring all their subjects sufficient salt from a common store and at a standard price by monopolizing all salt sources and their distributing mechanisms. The ancient Egyptians had a salt monopoly, as did China from the seventh century BC. Salt was also one of the first commodities to be taxed.
“The art of taxation,” said the seventeenth-century French statesman Jean Baptiste Colbert, “consists of plucking the goose so as to obtain the most feathers with the least hissing.” Colbert could not have spoken of taxation without an implied reference to the Gabelle, the famous French salt tax. He could not, perhaps, have guessed that his particular goose would one day do a great deal more than hiss.
The Gabelle was instituted in 1259 by Charles of Anjou in Provence, in imitation of the Arabs, who were the first since the fall of Rome to re-introduce the concept of salt monopoly and salt taxing. (Al quábala, “tax” in Arabic, is the origin of the word Gabelle.) The French kings began to use the system in the fourteenth century, and it spread all over Europe. France kept on using it in spite of inefficiencies, irritations, abuses, and riots, even despite its status as one of the causes of the French Revolution, until 1945. (Its abolition by the Revolution lasted only fifteen years.)
Taxing salt had definite advantages. Salt sources were always well known, and salt transportation a cumbrous business which could easily be regulated: salt was taxed at frontiers and on entry to provinces and towns. Everybody ate salt in more or less equal amounts, so everyone paid the tax equally. (This is repugnant to our concept of taxing according to income; we should recall, however, that in the fourteenth century very few people had what we would call an income, and not everyone “without an income” was poor.) Honey can take the place of sugar, and margarine my be used instead of butter; but there is no substitute for salt. Demand for it, in the economic jargon of our own day, was “inelastic”: taxation could therefore realize dependable sums without changing people’s buying habits.
The salt tax was never accepted with docility. If the theory of the Gabelle is a lesson in crude economics, the history of it is also a lesson in tax evasion. People pretended to have lost their stores of salt in rain storms and household accidents, they clandestinely made their own salt by digging for it or by evaporating brine, they sold inferior salt at superior prices, smuggled it, and passed it to each other in secret. In England and Scotland, “every year 10,000 people are seized for salt smuggling,” wrote the Earl of Dundonald in 1785, “and 300 sent to the gallows for contraband trade in salt and tobacco.” He thought civilized people should tax hearths (as England had once done) instead of salt, for a hearth did not move around, and its owner was rich enough to own a house. A salt tax was almost as thorough as a census: everyone paid, rich and poor alike. The principle was thought important enough to warrant forcing each person to buy a certain amount of salt. And when the government needed more money, people were simply required to buy more salt. (We recall that originally salt monopolies were invented to assure each person’s supply.) Enforcement of a salt tax cannot be achieved without violation of privacy: inspectors would search people’s houses, peer into families’ cooking-pots, and haul offenders away from their dinner tables.
In 1825, after four hundred years of resentment, England abolished her salt tax. She was the first country to do so. The impetus was the growth of her empire, the Industrial Revolution, and the advancement of technology which was to reverse totally the role of salt in human history. Not much earlier, however, Britain had monopolized salt in India; in 1863 she abandoned the monopoly (already very unpopular in the colony) and imposed a salt tax. She simultaneously began exporting Cheshire salt to India, to sell it there at the same price as India’s own product.
Home salt-making—even looking for salt—now became a crime in India; the malangis or salt evaporators became almost extinct as a class. For many years unrest and real suffering grew in intensity. Poor Indian peasants, with their vegetarian and frequently monotonous diet, had a great hunger for salt. In 1923, almost a century after Britain had abolished the tax in her own country, the British government, with singular callousness, doubled India’s salt tax. Many British parliamentarians protested, with no result.
When Mahatma Gandhi was asked by the All India Congress Committee to initiate a “call to action,” he made a theatrically brilliant decision. He began a three-week pilgrimage to the sea, gathering followers as he went. On April 6, 1930, Gandhi reached Dandi Beach in Gujarat. After a ceremonial sea bath (salt water, like salt itself, means purity), Gandhi began to pick up salt incrustations which lay free for the taking on the beach. India’s fight for independence had begun.
Satyagrahis (non-violent activists) undertook to get India’s salt and sell it free of tax. They carried it from the beaches in their fists; police had no other way of confiscating it than to snatch it from them, handful by handful. Many were beaten and imprisoned; many more kept taking their place. The movement grew; satyagrahi salt, people said, was “as pure as blood.” Valuable jewellery was given away in exchange for a lump of salt wrapped in a leaf. Women came out of purdah to violate the salt laws; foreign salt was dumped into the sea; there were strikes, pickets, and giant meetings.
Finally Lord Irwin, Viceroy of India, made a pact with Gandhi in March 1931. People living near the salt sands and solar salt ponds could, as a result of this agreement, collect salt, or make their own, and sell it in local villages. The most irritating aspect of the salt tax—the prevention of free domestic use—was thus alleviated, although the commercial tax remained. At the signing of the pact, Irwin drank Gandhi’s health with a cup of tea, but the Mahatma asked for a glass of lemon juice and water, and added a pinch of salt. With superb timing and his instinct for the perfect symbol, he had tested his theory of non-violent resistance, and he now judged that the Indian people were ready and able to embark on the process of making the British leave India.
Salt is the only rock directly consumed by man. It corrodes but preserves, desiccates but is wrested from the water. It has fascinated man for thousands of years not only as a substance he prized and was willing to labour to obtain, but also as a generator of poetic and of mythic meaning. The contradictions it embodies only intensify its power and its links with experience of the sacred.
Salt brings flavour to life, and people accustomed to salt find their food tasteless, flat, and dull without it. This is the point of the folktale from which Shakespeare derived King Lear. In the original story, the youngest daughter of the king, unlike her articulate and dishonest sisters, tells her father that her love for him is not like silver or gold, as they had claimed, but “like salt.” Enraged, he throws her out of the palace. She eventually is to be married, and invites the king (who does not know who she is or recognize her under her veil) to the wedding feast. She has ordered all the food to be prepared without salt. The king, finding the dinner inedible, weeps for his youngest daughter and finally understands how important a pinch of humble salt is to man’s happiness. She identifies herself, the two are reconciled—and presumably the salt-cellars are produced with a flourish. The story shows that a daughter’s sincere love is unassertive and may be taken for granted, but it is dependable and irreplaceable. In refusing or in losing it, a father is left without the kind of thing that gives zest to life.
When Jesus called his followers “the salt of the earth,” he was telling them that they were irreplaceable, and that their mission was to give people what makes life worth living. There were few of them, but they were sufficient to season the whole earth, as a very little salt or a tiny bit of leaven is enough. They and their message would persevere and endure, as salt is the great conserver, the image of permanence. Jesus went on immediately, in Matthew’s Gospel, to use an image of light. The two metaphors are connected both by opposition (salt is in the earth, light must be raised on high; salt is tasted while light is seen), and by similarity, for salt has always been associated with fire and brightness.
Salt, once isolated, is white and glittering. It is the opposite of wet. You win it by freeing it from water with the help of fire and the sun, and it dries out flesh. Eating salt causes thirst. Dryness, in the pre-Socratic cosmic system which still informs our imagery, is always connected with fire, heat, and light.
For the alchemists, common salt (one of the elements of matter) was neither masculine nor feminine but neuter: the edible rock always has something a little inhuman about it; it disconcertingly sits astride categories. Salt does have to do with sex, however, because it is a dynamic substance which both alters itself and causes change. Like sex, it is exciting and dangerous and gives pleasure. Salt comes out of the sea like the goddess of sex, Aphrodite, whose name the ancient Greeks thought meant “sea-foam-born.” In European folk custom, impotence has traditionally been cured by a hilarious, bawdy salting of the disobliging member by a crowd of women.
Often priests or mourners or people who are in a state of crisis—those whom society has marginalized, for whatever reason—must observe a taboo on salt. Eating no salt, which is often accompanied by sexual continence, means a fight to maintain equilibrium at a time of turbulence and difficulty, when one has no need of the dynamic. It also means that one has left society, rejecting the enticements and the comforts of civilization, or that one intends to dramatize a profound discontent with the way society is conducting itself.
Salt represents the civilized: it requires know-how to get it, and a sophisticated combination of cooking and spoilt, jaded appetites to need it. Its sharp taste suggests sharpness of intellect and liveliness of mind.Salt (bright, dry, titillating, and dynamic) is synonymous in several languages with wit and wisdom.
It preserves things from corruption—even as it corrodes other things with its bite. A little of it fertilizes the land; a lot sterilizes it. Because salt stops rot and because it is fiery, salt is intrinsically pure. It is the child of the sun and the sea, two basic symbols of cleanliness and purity. Salt keeps meat safe for the winter and so feeds man; it is, therefore, a blessing. Salt also means barrenness, and it is, therefore, used for cursing. Its imperishable rock-nature, and its purity and wisdom make it the material of oaths and covenants, which guarantee, if the swearer breaks his oath, that malediction will fall upon him.
Salt as covenant-sealer signifies friendship and hospitality. The silver salt-cellar was a central and often highly decorative ornament on the banquet tables of all rich European families: it marked off the close friends of the family from those “below the salt,” who were not considered worthy of such intimacy. When someone inadvertently spills salt, it is considered unlucky because it signifies enmity and malediction. Leonardo da Vinci followed this tradition in his fresco of the Last Supper when he depicted Judas as upsetting the salt-cellar.
Here as before, however, salt is powerfully contradictory: because it is pure and strong, it counteracts malediction. Witches hate salt. They never served it at their sabbaths, and if you put some under a witch’s cushion she could not sit down: this was considered a sure-fire method of finding out whether someone was a witch or not. Devils also detest it. Therefore, if you are unlucky enough to spill salt, all you have to do is throw some over your left shoulder (where all bad spirits congregate) and the evil will be undone. An owl’s cry is a malediction: to neutralize it, one has to sprinkle salt on the bird’s tail.
Until recently, salt was part of the Roman Catholic baptismal ceremony (Luther banned it as Popish superstition). A few grains were placed on the baby’s tongue to signify purity, endurance, wisdom, power, uniqueness (“You are the salt of the earth”), and protection from evil. It was a sign of God’s friendship and his power over Satan.
Humphry Davy succeeded in separating the components of common salt in 1810. There was chlorine, a poisonous greenish gas; and sodium, a silvery quasi-liquid metal which burst into flame when it touched water, was corrosive for inorganic matter, and absolutely lethal to anything living. No conceivable use could be imagined for either ingredient, and each was so violently reactive that it could barely be contained or stored under laboratory conditions. People marvelled that the contents of their dinner-table salt-cellars should be shown to be so dreadful. Humphry himself was to inspire, in a bored sixteen-year-old chemistry student called E. Clerihew Bentley, the very first clerihew (the verse form has since become traditional, like the limerick):
Sir Humphry Davy
Abominated gravy.
He lived in the odium
Of having discovered Sodium.
It took many decades for the effects of the splitting of salt to take hold, but the truth was that salt would never look the same again, and the earth has never recovered from the shift in human perception; maybe it never will.
The power of chlorine was found to be applicable as a textile bleach, and this was to remain its principle function for a hundred years. The production of this chlorine from salt entailed, of course, the piling up of the noxious left-over sodium. Scientists began to search for a use for sodium.
Potash had been an ingredient since ancient times in the making of soap and glass. But in the eighteenth century a new function for potash was found in the creation of saltpetre for gunpowder. Whole forests were burned in Europe and her colonies to obtain potash for military use; glass and soap had increasingly to depend on natural soda to replace potash. This led to a shortage of soda—just at a time when soap, rather than lye, was increasingly in demand for household laundry: people living in cities had no access to wood, and lye cannot be made of coal ashes. The French chemist Michel-Eugène Chevreul discovered the nature of the action of alkali upon fat in the making of soap, and his compatriot Nicolas Leblanc developed a method of making soda (alkali) out of the previously maligned sodium. Waste had been turned to gold.
Artificial soda factories in Manchester by the 1850s were pouring out hydrochloric acid fumes and the “rotten egg” gas, hydrogen sulphide. These, combined with smoke from two million tons of coal burned per year, provoked the earliest dazed realization that perhaps a problem was being born. A use was urgently sought for the unfortunate by product of artificial soda, hydrochloric acid. It was found at last in the dye industry.
Meanwhile, research into further uses for sodium went on. Soda or sodium hydroxide were found to be effective in extracting aluminium from its ore—the first new major metal extracted from the earth in two thousand years. Then sodium hydroxide was applied to cellulose to create rayon, the first artificial textile. From this time on, sodium was admitted to be a highly productive chemical. Chlorine became a side-effect of sodium hydroxide production, and a use had now to be sought for the mounting quantities of it.
In the early twentieth century, chlorine’s bleaching properties were applied not only to textiles but also to wood-pulp for the paper-making industry. Then it was found that chlorine could disinfect water. But chlorine finally burst into stardom when it became indispensable in the making of vinyls and other plastics, solvents, pesticides and herbicides, and in the cooling, braking, and “anti-knock” fluids used in automobiles.
Chlorine is the basis of various defoliants and poisons for gas warfare; its compound chloroform was considered a miraculous pain-killer (until it was found to be more dangerous than ether). It is part of carbon tetrachloride, which was extensively used as a dry-cleaning spirit until other chemicals replaced it. Refrigerant fluids now depend upon chlorine as does the gas in aerosol cans. Plastic, pesticides, the aerosol can: all are the progeny of chlorine—and therefore of common salt.
We met pesticides and herbicides in the history of corn, as the miracle-workers of the modern “Green Revolution.” They are chlorinated hydrocarbons, man-made substances which have not so far been found in nature. They are not, therefore, unmade by nature either: they are “non-biodegradable” substances which, after use, add to the ever-growing quantity of wastes we cannot get rid of. In addition, the huge amount of chlorine required to make plastics, pesticides, aerosol cans, solvents, and other things leaves behind the rest of the salt from which it has been derived. The disposal problem, in other words, has reversed itself and reappeared: since 1970, sodium hydroxide (from which chlorine had been the unfortunate refuse) has become an excessive waste product of chlorine. What now shall we do with the unused sodium hydroxide…?
Because of the salting of our roads, and the necessity for “automotive fluids,” for aluminium, and for plastics in every car, the automobile is the world’s largest consumer of salt. (We recall that the history of petroleum, the fuel of the automobile, is also part of the history of salt.) Road-salting, which in the United States meant the sprinkling of thirty-three kilograms of salt per head of population in 1974, has now become so extravagant and widespread that it amounts to an actual redistribution of terrestrial salt. Fresh-water lakes receive hundreds of tons of salt run-off annually. The saline content of Lake Erie, for instance, increased five times between 1939 and 1971, mostly because of road salting.
Some of the richest farmland on earth is to be found in California. Two spectacularly fertile areas, the Imperial and the San Joaquin valleys, were once the possessors of deep dry soils with no water supply. They have been brought to life by vast artificial irrigation schemes. In 1901, the Imperial Valley began to be watered from the Colorado River, which had deposited its silts to create the rich soil in the first place, then changed its course. Thousands of miles of canals now carry water to every corner of the Valley, which produces feed-lots of grass for fattening cattle, and billions of vegetables of every kind, which are transported in refrigerated rail-cars for sale in every state in the United States and all over Canada. Because the Colorado River is a turbulent flooder, it has twice been dammed—by the Hoover Dam and the Imperial Dam—so that the water can be further controlled.
But the Colorado, because of the salty desert lands through which it flows, is also an unusually salty river. It carries with it the salt-laden run-off from other irrigated areas on its route, and evaporation from the huge dammed lakes concentrates its salinity further. A sixty-five hectare (160-acre) cotton field in one growing season receives about 1,800 metric tonnes (2,000 tons) of salt with the water of the Colorado, and the amount is steadily increasing in spite of vast funds being poured into desalination projects. The story of the San Joaquin Valley is similar, although on an even larger scale. When two huge new water projects are complete, nearly two million metric tonnes of salt will be deposited in the Valley, along with the water, every year.
Holland has a comparable problem: its underground soils are already salted by sea water, and its fresh-water source is the salty and chemical-laden Rhine. Egypt’s Aswan Dam has eliminated the periodic flooding of the Nile, which used to wash salts out of the region’s topsoil. A vast new drainage system to combat salt build-up is now being constructed at a cost of a billion dollars. It will be able to correct salt damage to part of one small valley only. It is estimated that salt spread by irrigated agriculture will have destroyed between 50 and 65 per cent of all artificially watered land on earth before the end of this century.
The only remedies seem to be better drainage, and the leaching of the excess salt from the soil by pouring millions of gallons of fresh water over and through it. But the drainage schemes cost more than the original irrigation systems did; and unpolluted water is swiftly becoming a precious commodity, not to be wasted as a mere washing facility for salty soil. Scientists are fighting to find salt-resistant hybrid strains of cotton, of lettuce, of tomatoes, and the rest—so far without success. Salt-tolerant strains of food plants simply produce too little, and no one yet has found a way out of what appears to be nature’s rule: the higher the growth rate, the more salt-sensitive a plant will be. The most promising work being done at the moment is in juggling high-saline and less-saline water with the periods of plant life-cycles. For instance, low-salt water is kept for the germination of seedlings, high-salt water being permitted when the plant reaches six inches high, and so on. Relatively salt-resistant plants which remove some of the salt from the soil, are rotated with sensitive ones, and sloped beds are furrowed with salt-collecting depressions which are later flushed out to help cleanse the soil of salt. The organization and the technological cunning required to work all this out and to balance the whole panoply of strategies and varying conditions become more complex and expensive year by year.
Before 1850, everyone knew what salt was for: men ate it, shared it with their cattle, and used it to preserve food. It was complicated and often dangerous to get it and to supply it; most people received it in very limited quantities at the end of a long and hard journey. Ever since 1850, there has been a universal and continuous increase in human consumption of salt. The salt industry has been called “perhaps the most tangible realization of the ideology of perpetual growth.”
From time to time the public becomes aware of a strange new word, the name of a pollutant which is scarcely known outside laboratories and chemical catalogues until something nasty leaks onto a highway or spills into drinking water or poisons the air and forces its way into everyday human conversation. Most of these chemical pollutants (efficient in their place but lethal anywhere else) are in some way or other salt-derived, with chlorine or sodium designated in their unwieldy names. Examples are chlorinated phenols and the notorious poly-chiorinated biphenyls (PCBS).
The use of salt for culinary purposes has become “statistically insignificant” in relation to the quantities in demand for industry. The making of solar salt has declined dramatically because modern mining methods are increasingly fast, efficient, and similar all over the world. The ancient, almost esoteric arts of salt-winning have become completely inadequate to produce the huge tonnages of salt now required for industry. Trade in salt has dwindled, for with modern boring and geological expertise, any country can find its own salt deposits, which we now know to exist in or near most regions in the world.
The earth contains almost inconceivable quantities of salt: here is one resource we need never fear using up. However, getting salt and using it requires energy. Even primitive salt-boiling uses vast amounts of fuel: in its time the practice has caused timber shortages, wood- and coal-smoke pollution, and even human migrations. The principle fuel for modern chemical industries is oil rather than wood, and the main raw material for many chlorinated chemicals is also petroleum—but petroleum, unlike salt, is not inexhaustible, and unlike wood, is not renewable.
Salt, whose strangeness has always awed men’s minds, has never been less understood by ordinary people. Its secrets have become the preserve of chemists, whose complex and arcane skills cut them severely off from the comprehension of most of us. At the same time, never has common salt more effectively ruled human behaviour. The familiar salt-cellar appears at times to have unleashed a double demon with whose dance we Sorcerer’s Apprentices can barely keep up. If we are ever to gain the upper hand, we shall have to exorcize him, salt his tail with sodium chloride, the ancient symbol of wisdom itself.