Justus Von Liebig

Born May 12, 1803, in Darmstadt; died Apr. 18, 1873, in Munich. German chemist. Corresponding member of the St. Petersburg Academy of Sciences from 1830; president of the Bavarian Academy of Sciences from 1860.

Liebig was a professor at the universities of Giessen (from 1824) and Munich (from 1852). In 1825 he established a laboratory in Giessen for practical instruction, where many noted chemists studied and worked.

Liebig’s principal studies were in organic chemistry. In 1823 he discovered that silver fulminate, AgONC, is identical in composition to silver cyanate (the first example of isomerism). In 1832 he and F. Wöhler demonstrated that the transfer of one single group of atoms (C₆H₅CO), which they called the benzoyl radical, from one compound to another invariably occurs during various transformations of bitter almond oil (benzaldehyde, C₆H₅COH). Liebig’s studies contributed to the acceptance of the theory of radicals. In 1831 he first obtained chloroform, simultaneously with but independently of the French chemist E. Souberain. He also obtained acetaldehyde (1835) and discovered hippuric, lactic, and other carboxylic acids. Liebig perfected a method of determining carbon and hydrogen content in organic compounds (1831–33). Beginning in 1839, he carried out studies on the chemism of physiological processes and proposed a chemical theory of fermentation and putrefaction.

Liebig is considered to be one of the founders of agricultural chemistry. In 1840 he advanced the theory of mineral plant food, which promoted the wide application of mineral fertilizers in agriculture. In 1832 he founded the journal Annalen der Pharmacie (published under the title Annalen der Chemie und Pharmacie from 1840 to 1873; renamed Liebigs Annalen der Chemie in 1873). He established a scientific school. Many eminent Russian chemists were Liebig’s students, including A. A. Voskresenskii, N. N. Zinin, and L. N. Shishkov.