Salt: A World History

Kurlansky states that salt for food has become steadily less important since the beginning of the Industrial Revolution. A Paris cook named Nicolas Appert invented a method of sealing food in a jar and then heating the jar, which preserved the food inside. A Londoner named Peter Durand refined Appert’s idea and received a patent for preserving food. He also thought that tin might work better as a preservative than glass. “Bryan Donkin, a visionary early British industrialist, realized, perhaps better than Durand had, the potential of the tin idea” (304), and he founded the first canning plant and provisioned the military, as well as the crews of arctic expeditions.

As canned food grew in popularity, the salt industry began to collapse. “A twentieth-century invention [canning] dealt an even worse blow to the salt fish industry and, for that matter, to fish” (304). People packed fish in ice, which seemed to preserve it as well as salt. A man named Clarence Birdseye created a “fast-freezing process” (306). He demonstrated his new technology in Washington with a “block of ice, a fan, and a bucket of brine” (306). Food frozen quickly resulted in only small ice crystals, which did not alter the tissue of the fish and were better for preserving the fish in its original state.

In 1925, Birdseye created a frozen seafood company, and “[t]he railroad, faster transportation, and a better market system […] introduced more people to fresh fish. By 1910, only 1 percent of the fish landed in New England was cured with salt” (307). Birdseye’s company became General Foods. By the time he died at age 69, he had over 250 patents.

Kurlansky writes that “[p]umping brine was one of the most important engineering problems confronting salt makers, and it inspired many inventions” (308). Some of these inventions and innovations concerned transportation. The Anderton boat lift, for instance, was capable of lowering a fully-loaded salt barge into a canal, “[b]ut it was in the technology of drilling […] that salt producers had a momentous impact on the modern world” (309). Rotary drilling—in which a drill bit spins, as opposed to simply hammering through rock—made it possible to drill deeper than ever before. Improvement in drilling, and geologists were excited about new opportunities and means to explore the earth.

Before there were geologists, the contemplation of the earth’s makeup was the realm of natural philosophers. The origin of salt was itself a key question. There were theories that a bed of salt on the ocean floor kept the water salted, or that salt was carried to the sea by rivers. A 17th-century philosopher named Robert Hooke posited that salt came from the air. Kurlansky writes that “[t]here is still not complete agreement on the formation of the earth’s many great salt deposits. But they are generally agreed to have their origin in oceans rather than volcanos, though there is still no set explanation for the saltiness of the sea” (313).

Salt prospectors were able to locate salt deposits by finding 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” (314). Salt drillers who penetrated a dome often found oil. Two men, Pattillo Higgins and Anthony Lucas, drilled a salt dome in Texas that was named Spindletop. They discovered enough oil to begin the petroleum age in America: “As a result of Spindletop, the United States surpassed Russia, the largest oil producer at the time” (315). 

In Cheshire, England, important deposits of rock salt were found under Northwich and Winsford in the early 20th century. There had been sinkholes forming suddenly across the country, leading to the collapse of buildings, and sometimes even towns. Salt miners were blamed for making so many mine shafts that the integrity of the earth’s structure was deteriorating beneath the towns. But “there were not even 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” (321). Eventually, even railroads and bridges were being threatened by the encroaching sinkholes.

Cheshire became the butt of jokes, and the focus of religious zealots, who believed the sinking to be evidence of God’s wrath: “The problem was that if large quantities of brine were removed, they were replaced with large quantities of freshwater that hungrily absorbed considerable amounts of salt” (323). The freshwater then eroded pillars of salt that had been foundational to the support of the earth above.

In 1887, sixty-five salt producers sold their saltworks to the corporation Salt Union, which prompted fears of a monopoly. Others argued that the Salt Union could standardize rates of pumping and mining, which would hopefully reverse the spread of sinkholes, instead of having dozens of saltworks performing at their own paces and using a variety of methods.

Kurlansky gives the stories of the Thompson and Stubbs families, citing them as examples of England’s “eccentrics who stubbornly cling to quaint and hopelessly outmoded ways,” and also calling them “entrepreneurs who created the Industrial Age” (326). The Stubbs ran their saltworks with technological innovations that were responsible for their success. The Thompsons were in business because saltworks had been in their families for generations. Their secret was longevity. In the 1870s, most of the Stubbs and Thompson producers sold to Salt Union.

In 1905, “James Stubbs went to Michigan to learn about a new ‘evaporator’” (328). This steam evaporator allowed salt to be produced in a manner in which every grain was the same size. The Stubbs’ family would import their first salt evaporators to England by 1930. Kurlansky writes that “[t]he Stubbses, along with the Salt Union, are among only three surviving commercial British salt producers” (329). The Thompsons did not industrialize or adapt to new technologies and were out of business within a decade.