Background
Lehmann was born on August 4, 1719, in Langenhennersdorf, Germany. He was the son of Martin Gottlob Lehmann, a prosperous gentleman farmer, and Johanna Theodora Schneider.
Augustusplatz 10, 04109 Leipzig, Germany
In 1738 Lehmann matriculated as a medical student at the University of Leipzig.
Universitätsplatz 10, 06108 Halle (Saale), Germany
In 1739 Lehmann transferred to the University of Wittenberg, where he studied with the anatomist Abraham Vater. He received the M.D. in 1741, with a dissertation on the nervous papillae.
geologist mineralogist scientist
Lehmann was born on August 4, 1719, in Langenhennersdorf, Germany. He was the son of Martin Gottlob Lehmann, a prosperous gentleman farmer, and Johanna Theodora Schneider.
Lehmann's early education was largely at the hands of private tutors, although he did attend the Fürstenchule, in Schulpforta, for one semester in 1735 before ill health forced him to withdraw. In 1738 he matriculated as a medical student at the University of Leipzig; the following year he transferred to the University of Wittenberg, where he studied with the anatomist Abraham Vater. He received the M.D. in 1741, with a dissertation on the nervous papillae.
Lehmann went to Dresden to practice medicine, but soon, having become acquainted with the natural scientists resident there, discovered his real field of interest to be mining and metallurgy. Saxony, a mining center, was an ideal place to take up that subject, and Lehmann became encouraged in all aspects of it. He was particularly concerned with the origins and distribution of ore deposits and with the chemical composition of various ores. He made field trips, among them one to Bohemia, to further his knowledge, and by 1750, the year in which he left Dresden for Berlin, he had become known for his writings on mines and mining.
Lehmann initially came to Berlin in connection with the establishment of the state porcelain factory there. He did not participate in this enterprise for long, since shortly after his arrival he received an official commission to study mining procedures in the Prussian provinces and to make recommendations for their improvement. He spent several years on this project, mostly in the Harz. In August 1754 Lehmann was appointed Bergrat; he served as director of copper mining and of the Bureau of Mines in Hasserode, where he also established a smelter and factory for manufacturing blue pigment from cobalt from a neighboring mine. In 1755 and 1756 Lehmann traveled in Silesia in his official capacity.
In 1756, Lehmann settled in Berlin, having married Maria Rosina von Grünroth. He had been a member of the Royal Prussian Academy of Sciences since 1754, and his work in the capital was done largely under the auspices of that body. Lehmann thus entered into a period of extraordinary scientific activity, publishing his researches in chemistry, geology, and mineralogy. Of these, the most important and lasting were his geological studies.
Lehmann’s work in chemistry - which, indeed, constituted the greatest part of his researches - is today primarily of historical value. He analyzed many minerals for the first time; these analyses led to the discovery of new metals, including cobalt and tungsten. Lehmann’s Cadmiologia of 1760 dealt specifically with cobalt ores, treating their occurrence, mineralogy, and chemistry, and the technology necessary to their mining and Commercial. But because he was mining and commercial use limited to the techniques of quantitative analysis, Lehmann was able to make no fundamental and lasting contribution to the development of chemistry.
Mining technology was the framework into which Lehmann fitted all his research. He consciously sought to introduce into mining new scientific findings from all the natural sciences to enrich the technology that had evolved over the centuries. An uncompromising empiricist, Lehmann brought this point of view to his work in the field, in the mine, and in the laboratory. Following in the steps of Karl Friedrich Zimmermann, Lehmann advocated the establishment of specialized research institutions; he envisioned a technical teaching and research institute that would be the equal in prestige of the established universities. He was rewarded in his efforts by the founding of the Freiberg Bergakademie in 1765.
In 1760 Lehmann was invited to St. Petersburg by the Imperial Academy of Sciences. He accepted the following year, and in July 1761 left Berlin for Russia, where he took up a post as professor of chemistry at the University of St. Petersburg and director of the Academy’s natural history collection. He also continued his researches and, in the five and one-half years that remained to him, made thirty-seven reports to the Academy on the composition of minerals, the smelting of ores, the composition of soils and peats, the commercial manufacture of alum, fossil remains, and the geological structure of both specific regions and of the whole earth. He proposed the establishment of a governmental department to supervise the exploration of Russia’s mineral resources through a cartographical survey of geological relationships.
In geology Lehmann emphasized the importance of geological strata in determining the history of the earth; he was also one of the first to seek physico-chemical explanations for the origin of mineral deposits within the context of that history. His new notion of the composition of the earth further enabled him to reach a theory of the propagation of earthquakes as being dependent on the “inner structure of the surface of the earth.”
In his Versuch einer Geschichte von Flötz-Gebürgen of 1756, Lehmann, in discussing sedimentary rocks, described and compared sequences of strata on the basis of his own novel observations. Recognizing that the older strata were formed by the action of water, he developed the laws governing the formation of mountains, making a distinction between what he called “Ganggebürge” - a mountain formed of veined rock - and “Flötzgebürgen,” mountains formed of stratified rock. These are now called Unterbau and Oberbau (substructure and superstructure), respectively. Drawing upon his observations, Lehmann was to draw up the first geological profile. In it he demonstrated that rocks do not lie next to each other in a haphazard way, but rather are formed in historical sequence. He thus may be considered the founder of stratigraphy; his attempt to establish the laws underlying the formation of the earth provided the basis for modern geology.
An uncompromising empiricist, Lehmann brought his point of view to his work in the field, in the mine, and in the laboratory.
In 1756, Lehmann married Maria Rosina von Grünroth.