his work on "Organic Chemistry, in its Application to Agriculture" (Brunswick, 1840), which was translated into most European languages, and had an enormous circulation both in Europe and America. In 1845 he received from his sovereign the honor of an hereditary barony. Seven years later, in 1852, he accepted the position of Professor of Chemistry in the University of Munich, and director of the chemical laboratory of that city.
His principal works, besides those already mentioned, are: "Animal Chemistry, or Chemistry in its Applications to Physiology and Pathology" (1842); and "Familiar Letters" (1844), which brought his views on applied chemistry before a very wide public, in a style so simple and popular that practical agriculturists could understand and profit by the instruction there conveyed.
In 1848 he commenced the publication of his "Annalen," or, "Annual Report of the Progress of Chemical Science." He published his "Researches on the Chemistry of Food" in 1849. His "Dictionary of Chemistry," in which he had the assistance of other writers, appeared in parts between 1837 and 1851.
In estimating the relation of Baron Liebig to the thought of his age, we are not to regard him as simply a chemist; he was much more—he was, in its broadest sense, a philosophical chemist, a man of ideas. Since the death of Berzelius, no man has appeared who had the weight of universal authority in chemical science. The subject has developed into such vastness of detail, that men can only become great by limiting themselves to special branches of it. Liebig devoted himself to organic chemistry, and even here there are other men who have probably surpassed him in the number and importance of their immediate contributions to the science. Yet, since Berzelius closed his career, no savant has appeared in the chemical field who has achieved so brilliant and conspicuous a position as Liebig.
He had in an eminent degree the traits of a successful pioneer in the world of thought. He was a man of impulse, sympathy, and enthusiasm, as well as of intellect. He could not give his life to simple, quiet laboratory investigation, content to make a few additions to the stock of scientific truth. Although trained to the strict methods of investigation, and competent to bend his energies to specific research, yet his manly interest in his fellow-beings, and the welfare and progress of society, determined the course of his studies, and led him constantly to the development of large practical results. When he began with organic chemistry, it was in its infancy, and chiefly confined to the production of a few organic compounds by laboratory decomposition. As for the chemical interpretation of the living organism, it was hardly thought of. The mystery of the vital forces reigned supreme, and barred the way to true inductive investigation. So also with agricultural chemistry. Davy had originated the name early in the century, and presented some of its elementary facts; but they did
