Encyclopædia Britannica, Ninth Edition/Liebig, Justus

LIEBIG, (1803-18 37  73 ), was born at Darmstadt in 1803. His father carried on business as a drysalter and dealer in dye-stuffs, and made various experiments with a view to improved methods of preparing and purifying his wares. These led the son to take an interest in chemistry, and to seek for knowledge in the chemical books and periodicals in the grand-ducal library, which is rich in scientific works. At home he employed his time in repeating, as far as the means at his command admitted, the experiments he found described in books, and thus while still a boy attained a theoretical and practical knowledge of chemistry comparable with that of many full-grown professors of the science. He determined to be a chemist, to devote his life to the pursuit of science. The only kind of chemist available for teaching purposes was the chemist and druggist, and accordingly Liebig, at the age of fifteen, entered the shop of an apothecary at Heppenheim near Darmstadt to study chemistry. He soon found out how great is the difference between practical pharmacy and scientific chemistry, and returned to Darmstadt, after ten months, to look for another and more likely way of attaining his object. After some months spent in study at home he entered the university of Bonn, which he soon left for Erlangen. There he attended the lectures of Kastner on chemistry, and, besides the study of allied sciences, devoted some time to make up for the almost total neglect of school work caused by his early love of chemistry. He was much influenced by the metaphysical speculations of Schelling, and in after life referred to this influence as injurious to him as a scientific investigator. In those days there were no laboratories accessible to ordinary students, and Liebig had to content himself with what the university could give him in the lecture-room and in the library. Both at Bonn and at Erlangen he formed a students' chemical and physical society for the discussion of new discoveries and speculations as these appeared in scientific books or periodicals. In 1822 he left Erlangen with the degree of Ph.D. By means of the liberality of Louis I., grand-duke of Hesse-Darmstadt, Liebig was enabled to continue his chemical studies in Paris. There he mile the acquaintance of Runge, Mitscherlich, and Gustav Rose. He attended the lectures of Gay-Lussac, Thenard, and Dulong, and, while carrying on the investigation into the composition and properties of the fulminates which he had already partly published, he attempted, as at Erlangen, to work up his neglected school studies. The results of his work on the fulminates were communicated to the Academy of Sciences, and attracted the favourable attention of Humboldt. who was at that time in Paris. Humboldt introduced Liebig to Gay-Lussac, who admitted him into his private laboratory as a pupil. Here he had opportunities of learning all the mysteries of the art from

one of the most skilful and ingenious of experimenters. It was on the advice of Humboldt that Liebig determined to become a teacher of chemistry, but difficulties stood in his way. As a native of Hesse-Darmstadt, he ought, according to the academical rules of the time, to have studied and graduated at the university of Giessen, and Humboldt had to use his influence to induce the authorities to forgive his having attended the foreign university of Erlangen. After examination his Erlangen degree was recognized, and in 1824, in his twenty-first year, he was appointed extraordinary professor of chemistry in the university of Giessen. Two years later he was promoted to the post of ordinary professor, which he held for twenty-five years, notwithstanding the most tempting offers from other universities. It was here, in the small town and small university of Giessen, that by far the most of Liebig's work was done. He began by remedying the evil which as a student he had himself felt. He induced the Darmstadt Government to build a chemical laboratory in which any student of the university might obtain a thorough practical training. It is difficult for us, who live in a time when nearly every university and many schools possess well-arranged and often well-endowed laboratories, to understand how great a revolution was made in the practical teaching of physical science by the foundation of the Giessen laboratory. We can form some idea of it by reading Liebig's articles on the condition of chemistry in Austria, and Prussia, in which he goes over in detail the means of teaching afforded in the various universities of those great countries. He tells us that in 1838 two young Prussians came to Giessen to study chemistry, unable to obtain entrance to a laboratory in their own country, but were ordered back again by the Prussian Government. Fortunately other Governments were less strict, or other students were less obedient, and crowds of young men anxious to study chemistry came to Giessen, and carried home the light there acquired. Partly by Liebig's urgent appeals to the interests and to the shame of the great German states, partly by the influence of his pupils, a great reform was effected, and German universities now vie with one another in offering opportunities of practical instruction in chemistry and the other physical sciences.

The amount and the importance of the laboratory work done by Liebig in Giessen were very great. Without considering here the work done by his students under his direction, of which no doubt a very large part was conceived by him, and in the execution of which he constantly contributed his assistance and advice, we shall look only at what appears under his own name. During the twenty-six years he spent at Giessen as ordinary professor, he contributed to scientific journals more than two hundred papers, about twenty of which were records of joint work, chiefly with Wöhler. During the same time he published his works on organic analysis, organic chemistry, chemistry applied to physiology and agriculture, his Chemical Letters, and many smaller treatises. From 1832 he was joint editor of the Annalen der Pharmacie, from 1837 of the Handwörterbuch der reinen und angewandten Chemie, and from 1847 to 1856 of the Jahresbericht der Chemie. These statements give some idea of the amount of his work; of its importance and of its effect on the history of science we shall speak later.

In 1845 he was raised to the hereditary rank of baron under the title of Freiherr von Liebig. In 1852 he accepted the invitation of the Bavarian Government to the ordinary professorship of chemistry in the university of Munich. This office he held till his death in 1873.

In private life Liebig was hospitable, courteous, and kindly. Honoured by all the great scientific societies of the world, and regarded by almost every one as the great authority in chemistry, he assumed no airs of superiority,

and lived the simple and quiet life of a German professor. Liebig's influence on the history of chemistry may be considered under five heads:—(1) the effect of the opening of the Giessen laboratory, and of Liebig's constant efforts to induce other universities to follow this example; (2) the improvements introduced by him in methods of investigation and in apparatus; (3) the discovery of new facts; (4) the development of theory; and (5) the application of chemistry to physiology, agriculture, and the arts.