Nicolas Leblanc

French chemist

• Born: December 6, 1742
• Birthplace: Ivoy-le-Pré, France
• Died: January 16, 1806
• Place of death: Saint-Denis, France

Leblanc, an amateur chemist, developed a process for making soda from salt that now bears his name. The use of limestone to cause this conversion was at the core of his process, which played a fundamental role in creating the modern chemical industry.

Early Life

Tragedy haunted Nicolas Leblanc’s (nee-kaw-lah luh-blahnk) life, but scholars do not agree about whether his numerous misfortunes were self-generated or the result of historical circumstances. His troubles began when his mother died not long after his birth in 1742 at Ivoy-le-Pré, a small town about 125 miles south of Paris. His father, an official in an ironworks, died in 1751, and Nicolas was sent to Bourges, about twenty miles northeast of his hometown, where he came under the care and influence of his father’s good friend, Dr. Bien. From him, Nicolas absorbed an interest in medicine, and, when his guardian died in 1759, Nicolas went to Paris to study medicine at the École de Chirugie. While studying to become a doctor, Leblanc became very interested in chemistry and began attending the lectures of prominent chemists and befriending them.

After obtaining his master’s degree in surgery, Leblanc began to practice medicine, but he continued to be interested in chemistry. After attending the popular lectures of the chemist Jean Darcet, Leblanc became a pupil of Darcet and through him met such chemists as Claude-Louis Berthollet, Louis-Nicolas Vauquelin, Antoine-François de Fourcroy, and Réné-Just Haüy.

Leblanc married in 1775, and his first child was born in 1779. His education had consumed the money left to him by his father, and his family responsibilities necessitated a greater income than he was obtaining from the fees paid by his patients. Consequently, in 1780 he became the private physician of Louis-Philippe-Joseph, the future duc d’Orléans. The patronage of the Orléans family also gave Leblanc the opportunity for chemical research. The duke was interested in chemistry, and he encouraged Leblanc’s work.

Life’s Work

Since his means were limited, Leblanc initially chose to study crystallization, a subject that required few supplies. The work that he did on crystal growth so impressed the French Academy of Sciences that a reviewing committee recommended the academy’s support for a project in which Leblanc would study methods of obtaining complete crystals of a wide variety of substances. Yet before its recommendation could become a reality, the French Revolution resulted in the academy’s dissolution, and it was not until 1802 that Leblanc was able to publish his work on crystallization.

Through his contact with the academy, Leblanc became aware of a prize that Louis XVI had established for a practical process for making soda (sodium carbonate) from common salt. During the late eighteenth century, the shortage of soda was becoming an acute problem. Much of French soda was manufactured from barilla, a plant growing along the coast of Spain. This meant that France was forced to pay large amounts of money annually to the Spaniards, and during times of war, which were frequent in the eighteenth century, soda supplies would become scarce and expensive. A need clearly existed for a locally produced artificial soda. While working for the duc d’Orléans, Leblanc became interested in applying chemistry to industrial problems. Most of his time was devoted to the synthesis of soda—a goal which, as he knew, other researchers were also pursuing.

According to his patent application, Leblanc began research on soda in 1784, but some scholars are skeptical of this early date because of the lack of specific records. Leblanc once stated that he got the idea for his process by reading Jean-Claude de la Métherie’s account of his visit to England and Scotland in 1788 to study British industry. In de la Métherie’s account, an erroneous soda-producing process is discussed directly after a section on iron industry, and some scholars believe that this juxtaposition gave Leblanc the crucial idea for his discovery: the use of limestone in helping to transform common salt into soda.

Leblanc’s method was straightforward. He first treated common salt with sulfuric acid to produce “salt-cake” (sodium sulfate), which he then mixed with coal and ground limestone. He heated this mixture in a furnace, and the resulting black ash was leached to obtain the soda. Leblanc probably prepared soda crystals by this process in the latter half of 1789, for he and his assistant J. J. Dizé went to England in October, 1789, to confer with the duke about the commercial development of the process. The duke, Leblanc, Dizé, and Henri Shée (the duke’s agent) then signed an agreement on February 12, 1790, the major provisions of which were that Leblanc would patent his process for making soda and the duke would furnish 200,000 livres to enable Leblanc and Dizé to carry out its commercial exploitation. In another agreement, signed about a year later, the duke, Leblanc, Dizé, and Shée stated the shares of future profits that each would receive.

The French Revolution delayed the implementation of these agreements. During this period, the duke abandoned his title, changed his name to Philippe Égalité, turned republican, and voted for the death of the king. These actions did not erase the Republic’s difficulties with the duke’s aristocratic background, but they permitted Leblanc to obtain a secret patent on September 25, 1791, which meant that he did not have to make a public disclosure of his method and that he obtained the exclusive right to exploit his process in whatever way he saw fit for a period of fifteen years. Between 1791 and 1793, with capital provided by Égalité, Leblanc oversaw the construction of a small factory at Saint-Denis, a town four miles north of Paris. This plant began to make soda.

Because of France’s war with Spain, the price of barilla rose dramatically, and the shareholders of the Saint-Denis factory reaped huge profits from their manufacture of artificial soda. Unfortunately, the initial success of the plant was short-lived, and, in July, 1793, the impossibility of obtaining sulfuric acid forced Leblanc to close the plant. He was unable to resume operations so long as stocks of sulfur and saltpeter were needed by the munitions industry.

The reopening of the plant was complicated further when Égalité, its principal owner, was tried and guillotined in November, 1793. Leblanc was compelled to leave the idle factory in Shée’s care and return to Paris, where he took a post in the Gunpowder Agency and became involved in various political activities. On January 28, 1794, the plant and its associated property were formally confiscated by the Republic. The political authorities, in their revolutionary exuberance, believed that they could use the plant to enhance the industrial power of the Republic. On the very day that local authorities placed the Saint-Denis plant under sequestration, the Committee of Public Safety adopted a decree on the manufacture of artificial soda and appointed Darcet and other scientists to collect and publish all available information on the process. The committee hoped that the free flow of information would help resolve the shortage of soda. Perhaps through patriotism, perhaps through fear, Leblanc divulged the secrets of his process to the Committee of Public Safety. Some scholars see the committee’s action as a great injustice to Leblanc, whereas others think that the committee showed Leblanc unusual consideration.

In either event, the publication of the Leblanc process did the war effort little good, and the report of Darcet’s group, which was published in June, 1794, concluded that the procedure for making soda devised by a Benedictine father named Malherbe was more economical than Leblanc’s. At the time that the Saint-Denis plant was nationalized, Leblanc had not yet been able to show the superiority of his method over all others. Nevertheless, he had expected to be employed by the Republic to direct the soda works for the good of the people. Instead, he was notified that his government salary would end after April 1, 1794.

Within a short time, Leblanc’s life was in disorder. Instead of running a profitable business, he found himself without a salary to support his ailing wife and their four children and severed from the discovery and factory on which he had planned his future. From this time until his death, his life became a dispiriting struggle against poverty.

Following the Reign of Terror, authorities sought to revive industrial enterprises, especially mining, and in June, 1795, the Committee of Public Safety sent Leblanc on a mission to the departments of Tarn and Aveyron in the south of France. His job was to resurrect the manufacture of alum, a substance widely used by dyers, paper makers, goldsmiths, and doctors. His salary and expenses were supposed to be paid by some of the people he was helping, but he received nothing; after thirteen months, he returned to Paris more impoverished and embittered than before. His proclivity for blaming his troubles on the authorities deepened.

Throughout these years of frustration, Leblanc continued the vain struggle to secure recompense for his soda process. His despair deepened when one of his young daughters died suddenly. Leblanc’s luck seemed to change in 1801, however, when the minister of finance finally ordered the works at Saint-Denis to be given to Leblanc and his associates, although the state continued to own a substantial portion of the enterprise. The remnant of Leblanc’s family returned to their former house on the factory grounds, and Leblanc tried to resume the production of soda but encountered insuperable difficulties. The plant had been abandoned for seven years, and both the government and vandals had removed much of the best equipment and supplies. Leblanc also found himself competing with manufacturers whose plants had not suffered the misfortunes of Saint-Denis. He tried in vain to attract investors and to diversify his factory’s products, but each of these ventures consumed more of his time, energy, and money without enhancing his position.

Finally, on November 8, 1805, some of his claims, which had been in the courts for years, were recognized, and a board of arbitrators decided that, though most of Égalité’s business belonged to the state, Leblanc’s share was worth a sum equal to about $10,000. When even this inadequate sum was never paid, Leblanc became despondent. He had no income, his plant had failed, he was deeply in debt, and his wife was ill. His fortunes had reached bottom, and he increasingly withdrew into himself. Broken in spirit, he shot himself in the head on January 16, 1806.

Some scholars have suggested that Leblanc hoped that his suicide would shock the authorities into granting his family what they had previously denied him, but this did not happen. His death attracted little attention. In 1855, his achievements received belated recognition when Napoleon III made Leblanc’s heirs a payment in lieu of the prize for his discovery of the soda process. In 1887, a monument was erected in his honor in Paris that depicts him as a somber man with downcast eyes: His clean-shaven face and classical head would have been appropriate on the shoulders of an ancient tragic hero.

Significance

Nineteenth century industrial chemistry is largely the story of the rise and fall of the soda-making process of Nicolas Leblanc. In the middle of the century, the great English chemical manufacturer James Muspratt wrote that the Leblanc process had a greater impact on social life, commerce, and chemical technology than any other discovery. Though most twentieth century historians would not go as far as Muspratt, they too recognize the great importance of Leblanc’s method of producing soda in initiating the large-scale chemical industry. It is difficult to find an industry that was not influenced by the Leblanc process. For example, since the first step in the process depended on sulfuric acid, the expansion of Leblanc soda works was directly responsible for the growth of the sulfuric acid industry.

Unfortunately, Leblanc did not live to see the triumph of his method. Although he introduced his process in 1791, it did not become a significant producer of soda until two decades into the nineteenth century. By the time of Leblanc’s discovery, scientists knew more than a dozen processes for converting salt into soda, at least seven of which had been tested on a large scale; five establishments were actually manufacturing artificial soda, mostly in association with more profitable chemical products. None of these processes, however, could compete with natural soda, which France continued to import from Spain. Though Leblanc’s process was not completely novel, it was superior to these other methods, and it eventually came to be generally adopted. Leblanc himself did not really understand the detailed chemistry of the process he had discovered. In fact, the reactions of the Leblanc process were not precisely understood until the end of the nineteenth century, when the process itself began to go out of use.

During the 1820’s, the Leblanc process began its triumphant spread to other countries. James Muspratt built his first major soda plant in Liverpool in 1823. A few years later, Charles Tennant built a soda factory in Glasgow, and it quickly became the largest in Europe, covering 100 acres and employing more than one thousand workers. As these and other factories prospered, they encountered problems, because the Leblanc process, besides producing soda, produced poisonous fumes and large quantities of solid toxic wastes. Despite its obvious drawbacks, the Leblanc process dominated the industrial production of soda for nearly a century. It did not have a serious competitor until the end of the nineteenth century, when the process of a Belgian chemist, Ernest Solvay, proved its superiority. The Leblanc process continued to hold onto a significant proportion of the soda market until World War I, but its inevitable end came in 1923, when the last Leblanc soda works was scrapped.

The discovery, development, and decline of the Leblanc process are now part of the history of technology. Despite his deficiencies as a scientist and entrepreneur, Leblanc showed how soda, so vital to the glass, soap, dye, and textile industries, could be made cheaply from common salt. His process also led to the foundation of the first chemical industries to be operated on a massive scale, which forced technicians to develop new mechanical equipment to handle large amounts of material more efficiently. The disadvantages connected with the process also forced scientists to find ways to use or control the harmful by-products produced by the process. In this way the Leblanc process became the paradigm of not only nineteenth century chemical industry but also its twentieth century counterparts. Thus, Leblanc, a man who considered his life a dismal failure, became a posthumous success.

Bibliography

Brock, William H. The Chemical Tree: A History of Chemistry. New York: Norton, 2000. Chapter 9, “Chemistry Applied to Arts and Manufactures,” contains information on the alkali industry, including an account of Leblanc’s discovery and process.

Clark, Ronald W. Works of Man: A History of Invention and Engineering from the Pyramids to the Space Shuttle. New York: Viking Press, 1985. Clark offers an anecdotal history of technology from the invention of the wheel to the miniaturization of the electronic computer. He briefly discusses Leblanc’s work in connection with the development of man-made materials in the eighteenth and nineteenth centuries. Intended for general audiences and profusely illustrated with color and black-and-white photographs.

Daumas, Maurice, ed. The First Stages of Mechanization. Vol. 2 in A History of Technology and Invention: Progress Through the Ages. New York: Crown, 1969. This volume has chapters written by distinguished experts and represents original work rather than a synthesis of secondary sources. Lavishly illustrated with hundreds of photographs, drawings, and diagrams, this book provides a chronicle of industrial civilization told largely through the creative technical ideas of Leblanc and other inventors.

Gillispie, Charles C. “The Discovery of the Leblanc Process.” Isis 48 (1957): 152-170. Offers a revisionist view, attacking the so-called legend of Leblanc, the chemist whose discovery of the artificial soda process should have garnered him rewards but instead made him a victim of the revolution. Gillispie believes this legend rests on very shaky information, almost all of which comes from a memoir published in 1884 by Leblanc’s grandson, and that Leblanc was more the victim of his own difficult personality than of the accidents of history.

Haber, L. F. The Chemical Industry During the Nineteenth Century: A Study of the Economic Aspect of Applied Chemistry in Europe and North America. Oxford, England: Clarendon Press, 1958. This history of chemical technology, with an emphasis on economics, centers on the inorganic chemical industries and especially on four materials that governed the rate of expansion in the industry as a whole: sulfuric acid, soda ash, caustic soda, and bleaching powder. The changing role of the Leblanc process is studied in some detail. The technical and economic factors causing the rise and decline of Leblanc soda works in different countries and at different times form a major theme of this book.

Oesper, Ralph E. “Nicolas Leblanc (1742-1806).” Journal of Chemical Education 19/20 (1942/1943): 567-572. A major source for Leblanc’s life and work in English. Presents a fairly detailed account of Leblanc’s life, the genesis of his process, his efforts to obtain recompense for his discovery, and his tragic end. In contrast to the Gillispie article (see above), Oesper blames circumstances rather than Leblanc for Leblanc’s misfortunes.

Partington, J. R. A History of Chemistry. Vol. 3. New York: Macmillan, 1962. Contains information on the origins of some important chemical industries, including a detailed account of Leblanc’s work. Partington bases his text almost entirely on original sources, and he gives many quotations from these sources. His approach is encyclopedic rather than analytic, but this is a reliable source for those without the time or language skills to prospect through the original material.