Justus von Liebig

German chemist

• Born: May 12, 1803
• Birthplace: Darmstadt, Hesse-Darmstadt (now in Germany)
• Died: April 18, 1873
• Place of death: Munich, Germany

Liebig was one of the most important chemists of the nineteenth century. In addition to pioneering experimental research that transformed the basis of modern organic chemistry, his studies on agriculture led to the development of agricultural chemistry, and his systematic processes for training students became institutionalized within the German research university.

Early Life

Justus von Liebig (LEE-bihk) was the second of nine children of Johann Georg and Maria Karoline Moserin Liebig. His father was a dealer in pharmaceuticals and paint supplies, and Justus developed an interest in chemistry and experimentation at an early age. As a young boy, Liebig was especially fascinated with the explosive properties of silver fulminate, and his experiments with this material resulted in an explosion that prematurely ended his career as an apothecary apprentice.

After returning home for a short time, Liebig enrolled at the University of Bonn in 1820, where he studied under the chemist Wilhelm Gottlob Kastner. Later in life, Liebig was particularly critical of Kastner’s inability to teach him chemical analysis and the lack of adequate laboratory equipment, but Liebig followed Kastner from Bonn to the University of Erlangen, where he received a doctorate in 1822. It was at Erlangen that Liebig became convinced of the need to study abroad, and he successfully persuaded the Grand DukeLouis I of Hesse to award him a grant to pursue his chemical education in Paris from 1822 to 1824.

In Paris, Liebig received the chemical training that proved to be decisive and pivotal in his professional career. He attended the lectures of Louis-Jacques Thénard, Pierre-Louis Dulong, and Joseph-Louis Gay-Lussac and also gained entrance into the latter’s laboratory through the intervention of Alexander von Humboldt. Liebig would leave Paris thoroughly trained in critical thinking, in chemical analysis, and in the experimental methods necessary for making careful physical measurements, all hallmarks of the “new” chemistry first articulated by Antoine-Laurent Lavoisier at the close of the eighteenth century.

Life’s Work

Liebig returned to Germany in 1824 as extraordinary professor of chemistry at the University of Giessen; his appointment was the result of Humboldt’s successful efforts in convincing Louis I that the young chemist had exceptional promise. Although his laboratory initially consisted of only one room surrounded by benches along its walls with a coal stove at its center, Liebig would quickly rise from these humble beginnings to become Europe’s most distinguished chemist, the consequence of his personal charisma, scientific skills, and technical ingenuity.

Until the time of Liebig, organic chemistry was for the most part an inexact descriptive science based upon a hodgepodge of conflicting observations and personal opinions. There existed no practical classificatory scheme for organic substances, and there was little consensus concerning the fundamental building block of these materials, the molecule. Further, it was generally thought that a vital force arising from life itself was necessary for the synthesis of an organic compound. These uncertainties and others related to organic chemistry were ultimately explained by Liebig and his students using data gained from chemical analyses derived from the use of his combustion apparatus. This simple glass triangle consisted of several bulbs filled with potash, and it enabled the chemist to determine the percentage of carbon in a compound with great accuracy, precision, and relative ease. The combustion apparatus proved to be at the heart of Liebig’s success, revolutionizing both organic chemistry and nineteenth century chemical education.

The use of exact analysis did much to elucidate the nature of chemical compounds such as alcohols, aldehydes, ethers, and ketones during the late 1820’s and 1830’s. In the Giessen laboratory, where much of this compound characterization was done, large numbers of students, admitted on their talents and attracted by the low cost, flocked to the charismatic Liebig. Although their training encompassed both theoretical and practical chemistry, the combustion apparatus was an integral part of a systematic curriculum that enabled even the average worker to make valuable contributions.

Typically, the beginning student first sat in on Liebig’s lectures on introductory chemistry and then was initiated in laboratory practices by doing qualitative analysis in which one characterizes a series of unknown compounds. Subsequently, a varied set of quantitative analyses was performed, followed by exercises in preparative chemistry in which certain substances were synthesized. After successfully completing these stages, the student was permitted to pursue independent research, often using the combustion apparatus to explore the reactions and compositions of organic substances. Because Liebig was editor of his own journal, Annalen der Chemie und Pharmacie, his students often had no problem in rapidly publishing their findings to a scientific community that by the 1840’s recognized Giessen as the mecca of organic chemistry.

Without doubt, Liebig’s scientific reputation resulted in the best and brightest students in chemistry coming to study with him at Giessen during the second quarter of the nineteenth century. Among his students were August Wilhelm von Hofmann, discoverer of aniline and the first director of the British Royal College of Chemistry; Friedrich August Kekule von Stradonitz, whose structural interpretation of benzene was crucial to development in structural organic chemistry; James Muspratt of England, who was a leader during the late nineteenth century in the British chemical industry; and Oliver Wolcott Gibbs, who was a key figure within the emerging chemical community of nineteenth century America. Indeed, Liebig’s influence was truly international, as by the 1850’s most important academic positions in Western Europe were filled by his former students.

Liebig’s fame among his contemporaries and especially the public was perhaps not so much the result of his students and their work as the result of his opinions and writings on agricultural chemistry. In 1840, Liebig, weary after more than a decade of debate with the French chemist Jean-Baptiste André Dumas over the nature of organic molecules, gave a series of lectures on agricultural chemistry in Glasgow, Scotland, that subsequently would be the basis of Die organische Chemie in ihrer Anivendung auf Agricultur und Physiologie (1840; Organic Chemistry in Its Applications to Agriculture and Physiology , 1840). This work, which dealt with the uses of fertilizers, plant nutrition, and fermentation, was seriously flawed in its analysis but was so popular that by 1848 it appeared in seventeen editions and in nine languages, proving to be a powerful stimulus to the agricultural station movement in Europe and the United States.

In addition to his views on agriculture, Liebig also extended into the area of physiology and in 1842 expressed his views on nutrition and the chemical changes taking place within living organisms in Die Thier-Chemie: Oder, Die organische Chemie in ihrer Anwendung auf Physiologie und Pathologie (Animal Chemistry: Or, Organic Chemistry in Its Applications to Physiology and Pathology , 1842). Like his agricultural chemistry, Liebig’s animal chemistry aroused criticism that ultimately was crucial to the late nineteenth century development of modern physiological chemistry.

In 1852, Liebig left Giessen for a modern, well-equipped laboratory in Munich, where he would continue to research and write on aspects of organic chemistry. Although the latter stages of his career were not as fruitful as those early years at Giessen, his legacy in terms of ideas and of followers was crucial to the shaping of modern civilization.

Significance

Justus von Liebig perhaps did more than any other nineteenth century chemist in creating the modern synthetic world of the twentieth century. His reliance upon exact knowledge based upon chemical analysis resulted in the emergence of the discipline of organic chemistry, a field that has provided modern society with myriad synthetic products, including polymeric materials such as polyvinyl chloride, polypropylene, and synthetic rubber. However, Liebig did far more than influence the internal aspects of science, for his work on agricultural chemistry had enormous consequences in influencing what would become an ongoing agricultural revolution, and his speculations on physiology reoriented the course of medical research. Finally, his ideas on chemical education—ideas that continue to be practiced in universities today—mark perhaps his most lasting contribution, for most chemists trace their educational heritage to a small laboratory in Giessen and to its master, Justus von Liebig.

Bibliography

Beer, John J. The Emergence of the German Dye Industry. Urbana: University of Illinois Press, 1959. One important legacy of Liebig is in the creation of a modern synthetic world, the ultimate fruit of his many students working in industrial research laboratories during the last quarter of the nineteenth century. Beer’s study carefully traces the emergence of the science-based dye industry and the role of Liebig’s ideas in influencing its organizational development.

Brock, William H. The Chemical Tree: A History of Chemistry. New York: W. W. Norton, 2000. Includes information on Liebig’s writings, his experiences at the University of Giessen, and his work on combustion analysis, farming and fertilizers, and other aspects of chemistry.

‗‗‗‗‗‗‗. Justus von Liebig: The Chemical Gatekeeper. Cambridge, England: Cambridge University Press, 1997. Reprint. 2002. Discusses Liebig’s contributions to the field of organic chemistry, including his advocation of recycling sewage and replacing nutrients in the soil.

Ihde, Aaron J. The Development of Modern Chemistry. New York: Harper & Row, 1964. This survey work in the history of chemistry is excellent in characterizing the nature of organic chemistry during Liebig’s lifetime. Discusses Liebig’s contributions to organic, agricultural, and physiological chemistry as well as to the field of chemical education.

Levere, Trevor H. Transforming Matter: A History of Chemistry from Alchemy to Buckyball. Baltimore: Johns Hopkins University Press, 2001. This accessible history book includes information about Liebig’s experiences at the University of Giessen in Chapter 10, “The Birth of the Teaching-Research Laboratory.”

Lipmann, Timothy O. “Vitalism and Reductionism in Liebig’s Physiological Thought.” Isis 58 (1967): 167-185. A superb article that serves as a model for scholarship in the history of science. Lipmann demonstrates that while Liebig did not believe in the doctrine of vitalism as applied to organic compounds, he did adhere to the notion that a living force (Lebenskraft) was an essential part of physiological processes and necessary for the building up of organized structures in living bodies.

Morrell, J. B. “The Chemist Breeders: The Research Schools of Liebig and Thomas Thomson.” Ambix 19 (1972): 1-47. A penetrating study that examines the pioneering contributions of Liebig in establishing the first modern scientific research school. Morrell analyzes Liebig’s charismatic personality, the significance of the combustion apparatus, his ability to control the field of organic chemistry with Annalen der Chemie und Pharmacie, and his ability to secure financial and institutional resources.

Rossiter, Margaret W. The Emergence of Agricultural Science: Justus Liebig and the Americans, 1840-1880. New Haven, Conn.: Yale University Press, 1975. Traces the diffusion of Liebig’s ideas on agriculture from Europe to the United States during the nineteenth century. By the conclusion of the Civil War, a powerful movement to establish agricultural experiment stations emerged, and Rossiter particularly focuses on the influence of Liebig on those scientists working at the Connecticut Station.