Salt

by Mark Kurlansky

  IN THE LATE seventeenth century, when coal prospectors drilled into the Cheshire earth and found rock salt, it was the scientists, not the salt merchants, who were excited by the find. It demonstrated how improved drilling might someday open up an entirely new scientific field—geology, the study of the earth. Almost another century and a half would pass before England had its first systematic curriculum in the study of geology—established not by a geologist but by Humphry Davy.

  Long before there were geologists, there were natural philosophers who contemplated the structure of the earth. Some of their best ideas remained unproved and unembraced. Nineteen hundred years before Columbus’s voyages, Aristotle wrote that the earth was round. An eleventh-century-A.D. Persian physician, Avicenna, author of some 100 works on medicine and philosophy, wrote about land being formed by prehistoric flooding, erosion, sediment deposits, and the metamorphosis of soft rock. He might have been remembered as the father of geology if more people had understood what he was talking about. But it would take centuries for the scientific world to catch up with him.

  Throughout the Renaissance, new ideas were presented on the earth’s formation by thinkers in various fields, including Leonardo da Vinci, who opined that fossils were not, as widely supposed, placed in the rock by the devil but were formed by trapped plants and animals metamorphosing in the soil.

  In the mid–sixteenth century, Georg Bauer, a German with the pen name Georgius Agricola, wrote on the origin of mountains, minerals, and underground water. His 1556 work De re metallica was the most complete work to date and for centuries to come on techniques for mining and producing metals and minerals, including salt.

  Long before it was called geology, a number of geological debates persisted. One of them was on the origin of salt. Was a giant bed of salt at the bottom of the sea keeping ocean water salted? Or, as some believed, did the tremendous pressure at great depths so squeeze water that it turned salty? Another theory held that salt did not come from the ocean at all, but that salt on earth was carried to sea by rivers.

  In the seventeenth century, René Descartes asserted that sweet water was soft and would evaporate, but salt particles were hard and would remain, and that was why the sea remained salty. According to his theory, the soft part of the ocean, the freshwater, was absorbed in the earth’s pores and then reappeared in the form of freshwater rivers, streams, and lakes. The earth not only had pores, but also had cracks, and these fissures were wide enough to let in the seawater, particles and all. This seawater usually formed brine springs. But some of these fissures were dead ends and did not lead to springs. The seawater that seeped into such places hardened into rock salt.

  One eighteenth century theory held that the source of natural brine was that gypsum saturated with seawater leached salt. But another theory was that gypsum, a soft mineral common in most of the world, turned into salt. Water, according to this hypothesis, is salty in its natural state. The real question was: What caused freshwater not to be salty?

  Robert Hooke, the seventeenth-century philosopher whose many scientific accomplishments include originating the word cell for the basic organism, concluded that salt came from the air. Others concluded that salt came from alkali, which turns out to be true, since alkali are bases. Some combined the two, concluding that salt was caused by the alkali in seawater mixing with the salt in the air.

  The Germans tried to understand their many brine springs. Did brine come from rock salt below, as already appeared to be the case in Cheshire? Christian Keferstein, a Prussian lawyer, self-taught scientist, and author of a seven-volume geologic study, was convinced that the discovery of rock salt near a number of brine springs was coincidental. Rock salt, he believed, came from certain rocks.

  In the eighteenth and nineteenth centuries, the raging geologic debate pitted neptunism against plutonism. The neptunists, led by German mineralogist Abraham Gottlob Werner, believed that the source of all bedrock was a common ancient sea. According to plutonism, most rock had hardened from a huge molten rock mass. Neptunism held that salt came from the sea, and plutonism insisted it was volcanic in origin.

  In 1775, William Bowles used the salt mountain of Cardona to argue against the neptunism theory of salt. Logic indicated that such a huge mountain of solid rock was probably not left over from the ocean. Several others confirmed that this Pyrenees-sized mountain was solid salt or mostly salt—70 percent, one study contended—and that such a mass must have metamorphosized out of other rock. Eventually, neptunism was rejected, because both granite and basalt were proved to be of volcanic origin. But did that mean that plutonism was right about salt being formed by volcanos?

  In the nineteenth century, Europeans became extremely curious about the structure of salt deposits in other parts of the world, such as the Dead Sea. Thomas Jefferson was constantly questioned by Europeans about American salt formations, some of them mythical structures rumored to exist in the wilderness of the northern reaches of the Louisiana Purchase.

  As drilling improved, it became clear that the earth possessed huge underground salt deposits, and that far from being rare, rock salt was very common. By the end of the eighteenth century, many geologists were convinced that most of central Europe was sitting on an enormous salt deposit. To a large extent, they were right. The same salt deposit that feeds Alsace and Lorraine extends through Germany to the Austrian Salzkammergut. The thick layer of salt underneath Cheshire starts in Northern Ireland and runs into northern Europe. Onondaga County, New York, is part of an enormous salt field that stretches across the entire Great Lakes region, providing rock salt mines under the city of Detroit, in Cleveland, and in Ontario.

  There is still not complete agreement on the formation of many of the earth’s great salt deposits. But they are generally agreed to have had their origin in oceans rather than volcanos, though there is still no set explanation for the saltiness of the sea.

  Geologists, both out of curiosity and in search of salt, looked for salt domes, areas like Avery Island that had deep pure sodium chloride deposits forced by the pressure of shifting plates to mushroom up from the depths and break the earth’s surface in a dome shape. The history of salt dome theories begins with Thomassy, the Frenchman who said that Avery Island was rock salt. He stated that the salt there “comes from a volcano of water, mud, and gas.” This plutonistic theory of the salt’s volcanic origin was later rejected by most geologists.

  In 1867, C. A. Goesmann, reporting to the American Bureau of Mines, theorized that the salt under Avery Island resulted from brine springs ascending through older deposits of bedded salt. According to Goesmann, brine rises from deep within the earth, moving through the earth’s fissures and crystallizing near the surface.

  Salt prospectors were able to find salt domes by recognizing the rounded shape that protruded above the earth’s surface. They would drill in such spots, which invariably yielded brine, but often the salt was so contaminated with blackish muck that it was of little commercial value.

  In 1901, two men, Pattillo Higgins and Anthony Lucas, ignored the advice of geologists and started drilling a Texas salt dome called Spindletop. No one ever looked at salt domes the same way again. No longer were terms like well and drill rig to conjure up the image of salt. Spindletop had spawned the age of petroleum.

  Such an age had been promised in 1859, outside Titusville, Pennsylvania, where Edwin Drake, after studying the drilling techniques of salt producers, drilled 69.5 feet and, to everyone’s surprise but his, hit oil. He began producing twenty-five barrels per day, and many started to believe that oil would be an abundant U.S. resource. But subsequent drilling, mostly in the East, yielded little.

  By 1866, seven years after Titusville, when salt was discovered in Ontario, it was a different age. Canada had not produced much salt, but instead of excitement about a rich new salt field, there were high hopes that oil had been found. In Goderich, Ontario, Samuel Platt organized the Goderich Petroleum Company, which began work on the north bank of the Maitla
nd River—drilling 686 feet through gray limestone. There was no sign of oil, and the stockholders who had provided $10,000 in start-up money wanted to abandon the project. But the county council offered Platt a bonus of $1,000, and the city offered $500 provided he continue to a depth of 1,000 feet. At 964 feet from the collar of the hole, he hit solid rock salt.

  The Goderich Salt Company was founded with fifty-two boiling kettles, and the Ontario salt fields have become one of the most productive saltworks in the modern world.

  BY THE TIME Higgins and Lucas began drilling at Spindletop, hopes for American oil had faded. But Spindletop changed the thinking of geologists, chemists, engineers, and economists because it showed that a single spot, a corner of a single salt dome, could by itself produce enormous quantities of oil in a short period of time. In its first sixty-five years, Spindletop produced 145 million barrels of oil. As a result of Spindletop, the United States surpassed Russia, the largest oil producer at the time.

  Also because of Spindletop, geologists took a new look at salt domes. Because salt is impenetrable, organic material gets trapped next to the salt and slowly decomposes into oil and gas. For this reason, oil, gas, or both are frequently found on the edge of salt. The 2,000-year-old mystery of Sichuan was answered.

  After Spindletop, more oil was found along the Texas-Louisiana coast in such places as Sour Lake in 1902, Humble in 1905, and Goose Creek in 1908. The United States took the lead in a drilling technology that was now in demand all over the world, as geologists searched the globe for likely salt domes to drill. Many of them were found in the Persian Gulf. In 1908, oil was found in Persia, now Iran, in the places where Herodotus had written about salt.

  Exploration continued in North America. Few believed Columbus Joiner when he began drilling for oil on an unheard-of geologic structure he called “the Overton anticline.” It is now known that his theory of geology was completely wrong. But fortunately, at the time, no one could disprove it. They laughed at him, and he drilled anyway and found the largest oil field in North America, the East Texas Field.

  In a less corporate age, oil men used to take glee in pointing out that the three most important discoveries in the history of American oil—Titusville, Spindletop, and the East Texas Field—were all drilled against the advice of geologists.

  As Brownrigg had predicted in the mid–eighteenth century, “Old arts are improved and new ones daily invented.” The quest for salt had turned unexpected corners and created dozens of industries.

  CHAPTER TWENTY

  The Soil Never Sets On . . .

  WHEN THE BRITISH Empire was at its height, “Liverpool salt” was the salt of the empire, a prestigious product known all over the world. As in Cardona, Hallein, and Wieliczka, a visit to the Cheshire salt mines was a special treat for visiting aristocrats. These elite guests were lowered into the mines in enormous brine buckets. The candlelit bucket passed through the narrow shaft and when it came out at the mine below, the visitors were greeted by the word welcome spelled out by the workers with candles on the salt floor. According to local legend, when the czar of Russia visited England, he dined beneath Cheshire by the “light of a thousand candles.”

  It was the canals leading to Liverpool that had given Cheshire a global market. Not only was salt ballast for the voyage to America to pick up cotton and other imports for British industry, but, because the port of Liverpool was deeply involved in the slave trade, ships regularly bound for West Africa needed an outbound cargo. Nigeria bought Cheshire salt until 1968, when that market collapsed with the Biafran civil war.

  By 1890, besides the lucrative foreign market, Cheshire supplied 90 percent of British salt. In Cheshire, a good income could be had by anyone who could buy or lease a small plot of land near one of the wiches and who had the relatively small amount of capital needed to drill a hole in that ground and set up some wide, flat iron pans over a coal-burning furnace.

  Because the chimneys at Cheshire brine works were not built high enough for the wind to carry the soot and glowing cinders away, workers and townspeople lived amid burning black clouds—“the smoke and smother of weary Winsford,” as one newspaper described it in the 1880s. An 1878 royal commission reported that air pollution was choking the local vegetation. Salt producers were fined for the pollution, but this did not alter their practices. One producer told a board of inquiry that he would continue until the fines drove him out of business, and then he would relocate elsewhere.

  Tourists being lowered into a nineteenth-century Cheshire salt mine.

  The Salt Museum, Cheshire County Council, Northwich

  Salt did not provide an easy life. Often a man would rent a pan, and he, his wife, and children would ensure the maximum profit by working around-the-clock shifts to keep the pan in constant production. Children would start working at the salt pans at the age of nine. Women would go back and forth between the pans and their homes, alternating household work with salt making. A normal workday for a salaried salt worker was twelve hours, but it was often much longer. Some were paid by the hour and others by the quantity of salt they produced.

  Reform came slowly. An 1867 law forbade women and children to work between 6 P.M. and 6 A.M. Factory inspectors began protesting the working conditions for women, saying the work was too physically strenuous. And the public was scandalized when inspectors revealed that in the hot boiling houses, men and women worked together, the men stripped to the waist and the women, dresses removed, in their underwear and petticoats.

  An 1876 inquiry demanded that girls under eighteen be barred from saltworks. Robert Baker, one of the inspectors, argued for shorter workweeks for men. He told the board of inquiry, “The fact is the men never see beds but on Saturday night.”

  FOR CENTURIES, NANTWICH had been the leading Cheshire salt town. But in the early twentieth century, geologists discovered that the most important deposits were under Northwich and Winsford, where the thickness of the rock salt is as much as 180 feet and even at its thinnest, no less than 48 feet.

  The strange sinkholes that had been sporadically appearing in the eighteenth century had become by the late nineteenth century a regular phenomenon—not so much in Nantwich, but in and around Northwich and Winsford. Every year new spots in meadows, pastures, and even towns collapsed. The holes caught rainfall and made small lakes. Toward the end of the century, a lake of more than 100 acres suddenly appeared near Northwich. Sometimes saltworks made use of the newly developed holes, filling them with ash or lime waste, just one more pollutant in an area black with coal smoke.

  The brine makers tried to continue blaming the sinkholes on the rock salt miners, saying sinking was caused by abandoned mine shafts. This had worked better when rock salt was a new discovery. But in the nineteenth century, it became obvious that the location of the sinkholes bore no relation to the location of mine shafts, and as sinking became more frequent, there were not enough shafts to explain the number of occurrences. On the other hand, there was an exact correlation between the increase in brine production and the increase in sinkholes.

  Subsidence: office buildings sinking in Castle, Cheshire. The Salt Museum, Cheshire County Council, Northwich

  The sinking was starting to wreak havoc with railroad lines and even to threaten bridges. In Northwich and Winsford, homes and buildings collapsed as the ground gave way underneath them. By 1880, 400 buildings had been destroyed or damaged in Northwich alone. At Winsford, a new church was condemned as dangerous. Water mains, sewer lines, and gas pipes were continually breaking, and the costs of repairing them were draining municipal budgets. Shop after shop was condemned and torn down.

  A passing traveler described Northwich:

  A number of miniature valleys seem to cross the road and in their immediate neighborhood the houses are, many of them, far out of the perpendicular. Some overhang the street as much as two feet, whilst others lean on their neighbors and push them over. Chimney-stacks lean and become dangerous; whilst doors and windows refuse to open and close pr
operly. Many panes of glass are broken in the windows; the walls exhibit cracks from the smallest size up to a width of three or four inches; and in the case of brick arches over doors and passages, the key brick has either fallen out or is about to do so, and in many cases short beams have been substituted for the usual arch. In the inside, things are not much better. The ceilings are cracked and the cornices fall down; whilst the plaster on the walls and the paper covering it, exhibit manifold chinks and crevices. The doors either refuse to open without being continually altered by the joiner, or they swing back into the room the moment they are unlatched.—Chamber’s Journal, 1879

  With an English flair for genteel euphemism, the growing disaster was labeled subsidence. Subsidence in Cheshire was becoming a subject of considerable amusement around England, spawning Cheshire jokes. But it also drew religious fanatics, who went to Cheshire to deliver sermons to the crowds who came to gawk at the holes. The preachers would stand at the edge of the craters looking down into akimbo boiling houses and broken smokestacks and warn that this was what hell would look like.

  The truth was that too much brine was being pumped too rapidly from underneath Cheshire. Hundreds of ambitious small-scale entrepreneurs were making salt. They became extremely competitive. Some would pump additional brine out and dump it in the canals just to try to deprive their competitors.