Freiesleben, Johann Karl

(b. Freiberg, Saxony, Germany, 14 June 1774; d. Nieder-Auerbach, Saxony, Germany, 20 March 1846)

geology, mineralogy, mining.

Freiesleben came from an old Freiberg mining family. This circumstance, coupled with the active, centuries-old mining industry in the vicinity of Freiberg, determined his choice of mining science as his profession. While still a secondary school student he worked as a miner in pits and galleries. Freiesleben attended the Mining Academy in Freiberg from 1790 to 1792, and there he found a patron in Abraham Gottlob Werner, professor of geology and mineralogy. When Leopold von Buch and Alexander von Humboldt came to Freiberg in order to study under Werner, Freiesleben became friendly with both of them. He made his first scientific journey through Saxony and Thuringia with Buch, and with his friend E. F. von Schlotheim he explored the Thuringian Forest. With Humboldt he journeyed to Bohemia, and in 1795 they traveled in the Swiss Jura, the Alps, and Savoy. A lasting friendship developed between the two men. From 1792 to 1795 Freiesleben studied jurisprudence in Leipzig and often visited the Harz Mountains.

Upon returning from the journey to Switzerland, Freiesleben obtained a position as a mining official in Marienberg and Johanngeorgenstadt. In the latter city he married Marianne Caroline Beyer, the daughter of a clergyman, in 1800. In the same year he became director of the copper and silver mines in Eisleben. In this capacity he did much work in the technical aspects of mining and in science. He returned to Freiberg in 1808. There he joined the Bureau of Mines and was entrusted with the management of various governmental and corporate mines and metallurgical works. In 1838 he was placed in charge of all Saxon mining operations. He was pensioned in 1842. He died in 1846 after a short illness, while on an official tour.

Freiesleben was awarded a doctorate by the University of Marburg in 1817, and in 1828 he became a member of the Prussian Academy of Sciences in Berlin. He was a loyal friend and an adviser and benefactor to the lonely and needy; he was, moreover, closely bound to his family.

A product of Freiesleben’s trips to the Harz Mountains was one of his first major works: Bemerkungen über den Harz (1795), in which mineralogical and technical mining observations and descriptions stand out. Freiesleben completed his most important work, Beitrag zur Kenntniss des Kupferschiefergebirges (1807–1815), during his stay in Eisleben. In this he presents a painstaking and detailed description of the Permian Kupferschiefer and of the accompanying formations of the Zechstein and the Lower Permian Rotliegend, as well as of the Triassic. For decades this work remained indispensable to science and technology. Only when he attempted to trace individual formations into neighboring regions did he make errors. Thus he equated the limestone in the Swiss Jura and the Swabian Alb (now known as Mala) with the similar-appearing dolomite of the Zechstein (Upper Permian) in Thruingia and Saxony because of its many caverns. He also compared the Cretaceous Alpine limestone with the Upper Permian limestone, and the Cretaceous Quadersandstein of the northern edge of the Harz with the Triassic Bunter sandstone of Saxony.

Beginning in 1820 Freiesleben published the Magazin für Oryktographic von Sachsen. It consisted of individual volumes written by him and formed one of the most important sources of information about mineral occurrence in Saxony. Freiesleben himself composed twelve consecutive volumes and three special volumes; the remaining four volumes were published after his death. Of particular importance in this series is his work on the ore veins in Saxony (1843–1845). In this journal there are also descriptions of sediments and proof of the occurrence of fossil mammalian bones and teeth in Saxony (7, 1836).

Along with his scientific publications, Freiesleben was occupied with the administrative, technical, and mining matters connected with his official duties. He devised a series of technical improvements in mining and metallurgy, primarily in the mining of the Kupferschiefer in Eisleben and Mansfeld. He also found time to prepare for publication the extensive group of works on mineralogy, geology, and mining that he wrote while in office. Furthermore, during his years in Freiberg he maintained a constant interest in the administration and the social problems of his native city and was actively involved in them.

Freiesleben was one of the most gifted and most learned students of Werner, the leading geologist of the time in Europe. In his writings he helped to apply the theories of his teacher and to make them more widely known. Through his exact and reliable descriptions of the Permian and Triassic sedimentary formations in Saxony and Thuringia he pushed beyond Werner to a greater knowledge of the stratigraphic relationships of these periods in central Germany and helped to create the basis for stratigraphic comparisons with neighboring regions. His painstaking and accurate data on mining in Saxony and on the occurrence of minerals there are still valuable for historical purposes.

BIBLIOGRAPHY

I. Original Works. Freiesleben’s writings include “Geognostisch-bergmannische Beobachtungen auf einer Reise durch Saalfeld, Camsdorf and einen Theil Thüringens,” in Lempe’s Magazin für Bergbaukunde, 10 (1793), 3–114; Bemerkungen uber den Harz, 2vols, (leipzig, 1795) Geognostischer Beitrag zur Kenntniss, des Kupferschifergebirges mit besonderer Hinsicht auf einen Theil der Grafschaft Mansfeld und Thrüingerns, 4 vols, (Freibeg, 1807- 1815) Beyträge zur mineralogischen Kenntniss von Sachsen, 2 vols. (Freiberg, 1817); and Magazin für die Oryktographie von Sachsen, 1–12 and 3 spec. vols. published by Freiesleben; 13–15 and spec. vol. 4 published after his death by C. H. Müller (Freiberg, 1820–1848)

II. Secondary Literature. On Freiesleben or his work, see H. Claus, “Beiträge zur Geschichte der geologischen Forschung in Thüringen,” in Beiträge zur Geologie von Thüringen, I (Jena, 1927), 9–10; B. von Freyberg, Die geologische Erforschung Thüringens in älterer Zeit (Berlin 1932), pp. 25, 29, 32, 36, 41, 51, 59, 71, 82, 83, 88, 89, 90, 94, 101, 102, 106, 109; C. W. von Gümbel, “Freiesleben Johann Karl, “in Allgemeine dutsche BIographie, VII (Leipzig, 1878), 339–340, with bibliography; B. F. Voigt, “Johann Karl freiesleben, no 52 in Neuer Nekrolog der Deutschen, XXIV pt 1 (Weimar, 1848), 191–196, with bibliography; and K. A. von Zittel, Geschichte der Geologie and Paläontologie bis Ende des 19. Jahrhunderts (Munich– Leipzig, 1899), pp. 120–121, also pp. 93, 268, 494, 500, 608, 609.

Heinz Tobien