Justus von Liebig

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German chemist (1803–1873)

Liebig, who was born in Darmstadt, Germany, was the son of a dealer in drugs, dyes, and associated chemicals. Aided by his father he developed an early interest in chemistry and was apprenticed to an apothecary. He studied chemistry at Bonn and Erlangen, after which the grand duke of his native Hesse was persuaded to finance Liebig to pursue his chemical studies overseas. Consequently he went to Paris, where he worked in the laboratory of Joseph Gay-Lussac. While there he came into contact with Alexander von Humboldt, who exercised his patronage to have Liebig appointed to the chair of chemistry at Giessen in 1825, when he was still only 21. He remained there until 1852, when he moved to the University of Munich.

Liebig did much to establish chemistry as a discipline. At Giessen he set up one of the first laboratories for student instruction through which most of the great chemists of the 19th century passed. He also started the first scholarly chemical periodical. In 1832 he took over the Annalen der Pharmacie (Annals of Pharmacy) and renamed it in 1840 the Annalen der Chemie (Annals of Chemistry; the periodical still exists). He was constantly looking for ways to spread chemistry into new areas, to assert its dominance in previously autonomous disciplines. Thus in a series of works after 1840, when he moved from pure to applied organic chemistry, he tried to show that such studies as agriculture, physiology, and pathology were only intelligible when based on sound chemical principles. His Chemistry in its Applications to Agriculture and Physiology (1840) was one of the great books of the century. By 1848 it had gone through 17 editions and appeared in 8 languages. It was followed two years later by his Organic Chemistry in its Application to Pathology and Physiology.

Liebig's first significant discovery was made with the aid of Friedrich Wöhler, his lifelong collaborator and friend. While working in the laboratory of Gay-Lussac, Liebig had prepared silver fulminate; Wöhler working in Sweden in the laboratory of Berzelius had prepared silver cyanate. To their surprise these two different chemicals appeared to have the same formula. They had unwittingly discovered what Berzelius was to call isomerism, that is, the condition in which two different chemical compounds have the same molecular formula.

They decided to work together on the growing crisis in organic chemistry: how to deal with the sheer size and complexity of the molecules. (Molecules of inorganic compounds tend to be relatively small and straightforward and thus presented fewer problems.) Together they developed a method of analyzing the amounts of carbon and hydrogen present in organic compounds.

Liebig and Wöhler came up with a theory of compound radicals. In 1832 they introduced the benzoyl radical, arguing for the existence of a family of chemicals all made from the same radical with the addition of one or more atoms to differentiate them. Thus to the benzoyl radical, C₆H₅.CO, can be added OH to make benzoic acid, H to make oil of bitter almonds (benzaldehyde), Cl for benzoyl chloride, Br for benzoyl bromide, and so on. Unfortunately it was difficult to find another radical as productive and convincing as benzoyl. However, this could not detract from the important fact that they had shown that organic compounds could be dealt with in a rational way.

After organic chemistry Liebig's greatest work was carried out in agricultural science. His first achievement was in rejecting the current humus theory – the belief that plants absorb carbon from humus, the organic part of the soil, and turn it into the minerals they need. He demonstrated the falsity of this by showing that some crops left the soil richer in carbon than they found it, claiming that plants obtain carbon from the air. On burning plants he found various minerals present and argued that these must be obtained from the soil. He also thought that nitrogen was obtained from the ammonia in the soil, which ultimately derived from the rain. Thus plant growth could be stimulated with nitrates, manures, and minerals in which the soil was deficient. He experimented on a plot of land from 1845 until 1849 but had very disappointing results. Fearful of his additives being leached away he was using a fertilizer too insoluble for the plants to absorb. Once this was corrected, he demonstrated the power of minerals and nitrates in increasing crop yield.

During his visit to England he was shocked to observe the sewage of Britain being sent out to sea. He delivered a tremendous tirade against the British for their practice of importing bones from Europe instead of using their sewage as a fertilizer.

In the field of biochemistry Liebig became involved in a famous dispute with Louis Pasteur. As a supporter of Berzelius, he claimed that all chemical changes were brought about by catalysts and that no organisms were involved. In 1869 he argued that there was nothing biological about fermentation. Pasteur, however, managed to demonstrate that vinegar produced by wine souring on contact with air resulted from the action of yeast. In chemical physiology Liebig showed that animal heat could be entirely accounted for by the oxidation of food. Although he misrepresented the role of protein he pioneered attempts to calculate the calorific values of different foods.

Liebig was remarkable for the wide range of his work. There were greater chemists in the 19th century but none who worked with such authority over such an enormous field.

(1803-1873) German chemist; pioneered physiological chemistry; published Tieren Chemie in 1842; mistakenly concluded that protein provided the energy for muscle work (see also Fick, adolf; Wislicenus, johannes).

The German chemist Baron Justus von Liebig (1803-1873) was one of the pioneers in the field of organic chemistry and introduced the science of agricultural chemistry.

Justus Liebig was born in Darmstadt on May 12, 1803, the son of a druggist and dealer in chemicals. His early interest in chemistry may possibly be attributed to the fact that as a boy he was permitted to play with the chemicals in his father's laboratory. He was at first apprenticed to an apothecary, but after his experiments had blown out all the windows in the attic of the shop, this career came to a sudden end. He was then 15 and determined to study chemistry and devote his life to it.

Liebig was a student in chemistry at both Bonn and Erlangen and received his doctoral degree from the latter university in 1822. However, he was not satisfied with his knowledge and training and went to Paris, which was then an important center for chemical research. He worked first in the private laboratory of a chemist, and from there he was taken into the laboratory of the discoverer of gas laws, Joseph Gay-Lussac. Liebig worked there from the summer of 1823 until the spring of 1824.

When he returned to Darmstadt carrying impressive letters of recommendation from Gay-Lussac and Alexander von Humboldt, the Hessian government immediately appointed Liebig as assistant professor of chemistry at the small University of Giessen. Two years later he was made professor, but in 1852 he moved to Munich, where he remained for the rest of his life.

Years at Giessen

When Liebig arrived at Giessen, he found the small school poorly prepared for instruction in chemistry. He changed all of this and made Giessen the chemical studies center of the world during his stay of 28 years. He was described as one of the greatest chemistry teachers of all time.

Not the least of Liebig's accomplishments at Giessen was the elimination of practical chemistry training, that is, in methods for making soap, distilling spirits, manufacturing paints and varnishes, and other industrial procedures. He contended that no progress in chemical technology could be made until there had been established a firm theoretical foundation which was thoroughly understood by a new generation of chemists. Liebig predicted that the German chemical industry would gain great benefits from the scientific study of chemistry, and the latter half of the 19th century proved him to have been right.

The Giessen years were also marked by Liebig's close association with Friedrich Wöhler. Their partnership proved to be one of the soundest and most productive in the history of science. They became personally acquainted in 1824, when Liebig paid a visit to Berlin, and from that point on their partnership and friendship were confirmed. In 1832 they discovered the "benzoyl radical" (C₇H₅O), the importance of the discovery being its demonstration that in organic substances there are groups of atoms which hold together and in reactions act like elements. From this discovery Liebig was led to the discovery of the ethyl radical (C₂H₅), which is found in such compounds as alcohol and ether. Wöhler and Liebig published their results on experiments with uric acid in 1838.

At Giessen, Liebig produced chloroform and chloral, discovered hippuric acid, studied the alkaloids and the amino acids, and began his work in agricultural chemistry and in the chemistry of life itself. He was the editor of Annalen der Pharmacie (1832-1839), which was continued as Annalen der Chemie und Pharmacie after 1840. He developed a method of organic analysis which is still used today. Although many of his theories were modified by later research and increased knowledge, he did more than any other individual to raise chemistry to a preeminent position in 19th-century Germany.

Theories in Biochemistry

About the midpoint in his career Liebig turned his attentions to biochemistry, literally, the chemistry of living organisms. He began by making analyses of such tissue fluids as blood, urine, and bile, and he went on from those studies to a consideration of body metabolism in animals. Out of his researches he proposed the theory that body heat and the ability of muscles to do work came from the energy which the oxidation of foodstuffs such as fats and carbohydrates provided.

Liebig also turned his attention to the process of fermentation. Here he fell into error, for he believed that fermentation resulted from the transmission of vibration from the particles in the mixture, which he thought were in a state of violent motion. This theory regarded fermentation as being independent of living organisms, that is, as purely a chemical reaction. In the case of yeast, for example, he denied that it was living and became involved in a long dispute with Louis Pasteur on the question. In this controversy Liebig was the loser, as Pasteur was able to offer incontrovertible proof that fermentation depends upon the presence of living organisms such as yeast cells.

Agricultural Chemistry

Liebig inaugurated the study of plant chemistry and its relationship to agriculture. In his view, green plants supported all life, and they derived their life from inorganic elements found in the soil and in the air. Green plants, he stated, receive from the air carbon from carbon dioxide, and nitrogen from ammonia. He believed that ammonia was also a component of rainwater, so that plants had an ample supply. In this concept, he was later proved to be wrong, and eventually he advised the use of some ammoniacal salts in plant fertilization.

Liebig also found, through the analysis of hundreds of samples of plant ash, that plants contain elements such as sodium, potassium, calcium, and phosphorus. They were the mineral content of plants and must come from the soil itself. Liebig said that the mineral content of soils could become exhausted, rendering the land unproductive for agricultural purposes. It was known that soil could replenish itself; that is, if no crops were grown on a piece of land for a time, eventually it would regain its productivity. Liebig suggested that this natural process of replenishment be supported through the use of mineral fertilizers.

To this end, Liebig began to compound mineral "manures," fertilizers that contained phosphates and potash, and he added them in an insoluble state so that rain-water would not wash them away. It was later realized that plants need these minerals in a soluble state and are quite capable of holding them in the soil regardless of rainfall. In spite of his lack of pronounced success with chemical fertilizers, Liebig showed the way for other reseachers, and the modern chemical fertilizer industry may be said to be his offspring. Much of his work in this field is described in Chemistry in Its Application to Agriculture and Physiology (1840).

His Place in Chemistry

Liebig, who received many honors during the course of his life, stands out as perhaps the most influential of the many German chemists of his age. He was a pioneer in chemical education, a discoverer in the realm of organic chemistry, and the first chemist to give serious consideration to the application of chemical science to food, nutrition, and agriculture. He also began basic research in the highly complicated field of biochemistry. At the time of his death on April 18, 1873, in Munich, one of his students, A. W. Hofmann, wrote, "No other man of learning, in his passage through the centuries, has ever left a more valuable legacy to mankind."

Further Reading

The biographical literature on Liebig is mostly in German. W. A. Shenstone, Justus von Liebig: His Life and Work (1895), is a comprehensive biography in English. See also James R. Partington, A History of Chemistry (4 vols., 1961-1964); Aaron Ihde, The Development of Modern Chemistry (1964); Isaac Asimov, Short History of Chemistry (1965); and Eduard Farber, The Evolution of Chemistry: A History of Its Ideas, Methods, and Materials (2d ed. 1969).

Liebig, Justus von (Darmstadt, 1803-73, Munich), a distinguished German chemist, had a brilliant career at Bonn and Erlangen universities and was appointed a professor at Gießen University at the age of 21. He remained there until 1852, establishing the most successful school of chemical research in Europe at that time. In 1852 he became a professor at Munich. During his fruitful years at Gießen he discovered chloroform and chloral, and made important advances in the study of alimentary chemistry and metabolism. His patent of nobility was conferred in 1845 in recognition of his scientific distinction. Liebig's laboratory, which is preserved as a museum, survived the destruction of Gießen in 1945. The University of Gießen now bears his name (Justus-Liebig-Universität).

Quotes:

"Receiving a new truth is like adding a new sense."

Justus von Liebig
Justus von Liebig-chemist
Born	12 May 1803(1803-05-12) Darmstadt, Grand Duchy of Hesse
Died	18 April 1873 (aged 69) Munich, German Empire
Residence	Grand Duchy of Hesse, then German Empire
Nationality	Hessian, then German
Fields	Chemist
Institutions	University of Giessen University of Munich
Alma mater	University of Bonn University of Erlangen
Doctoral advisor	Karl Wilhelm Gottlob Kastner
Doctoral students	Carl Schmidt Nikolay Zinin Victor Regnault Carl von Voit Hermann von Fehling Hermann Franz Moritz Kopp August Kekulé August von Hofmann Lyon Playfair Emil Erlenmeyer Moritz Traube Adolph Strecker Wilhelm Henneberg ,
Known for	Discovery of Nitrogen Law of the Minimum Liebig condenser

Justus von Liebig (12 May 1803 – 18 April 1873) was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. As a professor, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the greatest chemistry teachers of all time. He is known as the "father of the fertilizer industry" for his discovery of nitrogen as an essential plant nutrient, and his formulation of the Law of the Minimum which described the effect of individual nutrients on crops. He also developed a manufacturing process for beef extracts, and founded a company, Liebig Extract of Meat Company, that later trademarked the Oxo brand beef bouillon cube.

Contents 1 Biography 2 Research and development 3 Major works 4 See also 5 Notes 6 References 7 External links

Biography

Liebig was born in Darmstadt into a middle class family. From childhood he was fascinated by chemistry. He was apprenticed to the apothecary Gottfried Pirsch (1792-1870) in Heppenheim.

Liebig attended the University of Bonn, studying under Karl Wilhelm Gottlob Kastner, a business associate of his father. When Kastner moved to the University of Erlangen, Liebig followed him and later took his doctorate from Erlangen. Liebig did not receive the doctorate until well after he had left Erlangen, and the circumstances are clouded by a possible scandal [see Munday (1990)]. Also at Erlangen, Liebig fell in love with the poet August von Platen-Hallermünde (1796-1835)^[1] who wrote several sonnets dedicated to Liebig. He left Erlangen in March 1822, in part because of his involvement with the radical Korps Rhenania (a nationalist student organization) but also because of his hopes for more advanced chemical studies.

In autumn 1822 Liebig went to study in Paris on a grant obtained for him by Kastner from the Hessian government. He worked in the private laboratory of Joseph Louis Gay-Lussac, and was also befriended by Alexander von Humboldt and Georges Cuvier (1769-1832).

After leaving Paris, Liebig returned to Darmstadt and married Henriette Moldenhauer, the daughter of a state official. This ended Liebig's relationship with Platen.

In 1824 at the age of 21 and with Humboldt's recommendation, Liebig became a professor at the University of Giessen. He established the world's first major school of chemistry there. He received an appointment from the King of Bavaria to the University of Munich in 1852, where he remained until his death in 1873 in Munich. He became Freiherr (baron) in 1845. He is buried in the Alter Südfriedhof in Munich.

He founded and edited from 1832 the journal Annalen der Chemie, which became the leading German-language journal of Chemistry. The volumes from his lifetime are often referenced just as Liebigs Annalen; and following his death the title was officially changed to Justus Liebigs Annalen der Chemie.

He was elected a member of the Royal Swedish Academy of Sciences in 1837.

The young Liebig: 1843 lithograph after an 1821 drawing (Liebigshaus)

Research and development

Liebig improved organic analysis with the Kaliapparat -- a five-bulb device that used a potassium hydroxide solution to remove the organic combustion product carbon dioxide.^[2] He downplayed the role of humus in plant nutrition and discovered that plants feed on nitrogen compounds and carbon dioxide derived from the air, as well as on minerals in the soil. One of his most recognized and far-reaching accomplishments was the invention of nitrogen-based fertilizer. Liebig believed that nitrogen must be supplied to plant roots in the form of ammonia, and recognized the possibility of substituting chemical fertilizers for natural (animal dung, etc.) ones. Nitrogen fertilizers are now widely used throughout the world, and their production is a substantial segment of the chemical industry. He also formulated the Law of the Minimum, stating that a plant's development is limited by the one essential mineral that is in the relatively shortest supply, visualized as "Liebig's barrel". This concept is a qualitative version of the principles used to determine the application of fertilizer in modern agriculture.

He was also one of the first chemists to organize a laboratory as we know it today. His novel method of organic analysis made it possible for him to direct the analytical work of many graduate students. The vapor condensation device he popularized for his research is still known as a Liebig condenser, although it was in common use long before Liebig's research began. Liebig's students were from many of the German states as well as Britain and the United States, and they helped create an international reputation for their Doktorvater.

In 1835 he invented a process for silvering that greatly improved the utility of mirrors.

Liebig's work on applying chemistry to plant and animal physiology was especially influential. At a time when many chemists such as Jöns Jakob Berzelius insisted on a hard and fast separation between the organic and inorganic, Liebig argued that "...the production of all organic substances no longer belongs just to the organism. It must be viewed as not only probable but as certain that we shall produce them in our laboratories. Sugar, salicin [aspirin], and morphine will be artificially produced." [Liebig and Woehler (1838)]

Liebig's arguments against any chemical distinction between living (physiological) and dead chemical processes proved a great inspiration to several of his students and others who were interested in materialism. Though Liebig distanced himself from the direct political implications of materialism, he tacitly supported the work of Karl Vogt (1817-1895), Jacob Moleschott (1822-1893), and Ludwig Buechner (1824-1899).

German stamp picturing Justus von Liebig, 1953

Liebig played a more direct role in reforming politics in the German states through his promotion of science-based agriculture and the publication of John Stuart Mill's Logic. Through Liebig's close friendship with the Vieweg family publishing house, he arranged for his former student Jacob Schiel (1813-1889) to translate Mill's important work for German publication. Liebig liked Mill's Logic in part because it promoted science as a means to social and political progress, but also because Mill featured several examples of Liebig's research as an ideal for the scientific method. Liebig is also credited with the notion that "searing meat seals in the juices."^[3] This idea, still widely believed, is not true.

Working with Belgian engineer George Giebert, Liebig devised an efficient method of producing beef extract from carcasses. In 1865, they founded the Liebig Extract of Meat Company, marketing the extract as a cheap, nutritious alternative to real meat. Some years after Liebig's death, in 1899, the product was trademarked "Oxo".

After World War II, the University of Giessen was officially renamed after him, "Justus-Liebig-Universität Giessen". In 1953 the West German post office issued a stamp in his honor.^[4]

Major works

• Organic Chemistry in its Application to Agriculture and Physiology (1840)
• Organic Chemistry in its Application to Physiology and Pathology (1842)
• Familiar Letters on Chemistry (1843)

See also

Wikisource has original text related to this article: The Chemical News/Justus Liebig (obituary)

• History of Soil Science
• List of chemists

Notes

1. ^ William H. Brock. Justus von Liebig: The Chemical Gatekeeper. Cambridge University Press, 2002, page 21
2. ^ Liebig, J. (1831). "Ueber einen neuen Apparat zur Analyse organischer Körper, und über die Zusammensetzung einiger organischen Substanzen". Annalen der Physik 21: 1 – 47. 
3. ^ McGee, Harold (2004). On Food and Cooking (Revised Edition). Scribner. ISBN 0-684-80001-2.  Page 161, "The Searing Question".
4. ^ Germany #695, Scott catalogue

References

• William H. Brock, Justus von Liebig: The Chemical Gatekeeper (Cambridge University Press, 1997). See also William H. Brock.
• Rosenfeld, Louis (2003), "Justus Liebig and animal chemistry.", Clin. Chem. 49 (10): 1696–707, 2003 Oct, doi:10.1373/49.10.1696, PMID 14500604 
• Kirschke, Martin (2003), "Liebig, his university professor Karl Wilhelm Gottlob Kastner (1783-1857) and his problematic relation with romantic natural philosophy.", Ambix 50 (1): 3–24, 2003 Mar, PMID 12921103 
• Buttner, J (2000), "Justus von Liebig and his influence on clinical chemistry.", Ambix 47 (2): 96–117, 2000 Jul, PMID 11640225 
• Thomas, U (1988), "Philipp Lorenz Geiger and Justus Liebig.", Ambix 35 (2): 77–90, PMID 11621581 
• Guggenheim, K Y (1985), "Johannes Müller and Justus Liebig on nutrition.", Korot 8 (11-12): 66–76, PMID 11614053 
• Sonntag, O (1977), "Religion and science in the thought of Liebig.", Ambix 24 (3): 159–69, 1977 Nov, PMID 11610495 
• Glas, E (1976), "The Liebig-Mulder controversy. On the methodology of physiological chemistry.", Janus; revue internationale de l'histoire des sciences, de la médecine, de la pharmacie, et de la technique 63 (1-2-3): 27–46, PMID 11610199 
• Sonntag, O (1974), "Liebig on Francis Bacon and the utility of science.", Annals of science 31 (5): 373–86, 1974 Sep, doi:10.1080/00033797400200331, PMID 11615416 
• Kempler, K (1973), "[Justus Liebig]", Orvosi hetilap 114 (22): 1312–7, 1973 Jun 3, PMID 4576434 
• Halmai, J (1963), "Justus Liebig", Orvosi hetilap 104: 1523–4, 1963 Aug 11, PMID 13952197 
• Berghoff, E (1954), "Justus von Liebig, founder of physiological chemistry.", Wien. Klin. Wochenschr. 66 (23): 401–2, 1954 Jun 11, PMID 13187963 
• Schmidt, F (1953), "To Justus von Liebig on his 150th birthday, 12 May 1953", Pharmazie 8 (5): 445–6, 1953 May, PMID 13088290 
• Schneider, W (1953), "Justus von Liebig and the Archiv der Pharmazie; in memory of Liebig's birthday, 12 May 1803", Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft 286 (4): 165–72, PMID 13081110 
• G. F. Knapp (1903). "Zur Hundertsten Wiederkehr: Justus von Liebig nach dem Leben gezeichnet". Berichte der deutschen chemischen Gesellschaft 36 (2): 1315 – 1330. doi:10.1002/cber.19030360202. 
• Georg Freiherr von Liebig (1890). "Nekrolog: Justus von Liebig. Eigenhändige biographische Aufzeichnungen". Berichte der deutschen chemischen Gesellschaft 23 (3): 817 – 828. doi:10.1002/cber.18900230391. 
• "Zur Erinnerung an Justus von Liebig". Journal für Praktische Chemie 8 (1): 428 – 458. 1873. doi:10.1002/prac.18740080148. 

External links

• Familiar Letters on Chemistry at librivox.org
• Works by Justus von Liebig at Project Gutenberg
• Works by or about Justus von Liebig in libraries (WorldCat catalog)
• Justus Liebig, German chemist (1803-73) from the Encyclopaedia Britannica, 10th Edition (1902).
•  "Liebig, Justus von". Encyclopædia Britannica (11th ed.). 1911. 

Awards and achievements
Preceded by Robert Brown	Copley Medal 1840 jointly with Jacques Charles François Sturm	Succeeded by Georg Ohm

Persondata
NAME	Liebig, Justus von
ALTERNATIVE NAMES
SHORT DESCRIPTION	Chemist
DATE OF BIRTH	12 May 1803(1803-05-12)
PLACE OF BIRTH	Darmstadt, Germany
DATE OF DEATH	18 April 1873
PLACE OF DEATH	Munich, Germany

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