Berlin, 1850. Single sheet (40.1 x 28.5 cm) with mezzotint portrait and printed signature as caption. Printed surface 25.5 x 21 cm.

A fine, unusually large portrait, of the famous German geologist Christian Leopold Freiherr von Buch (1774-1853). Printed by L. Sachse, after a painting by the German artist Carl Josef Begas (1794-1854). With very wide margins. Von Buch "...is remembered as one of the most important contributors to geology in the first half of the nineteenth century. His scientific interest was devoted to a broad spectrum of geological topics: volcanism, petrology, fossils, stratigraphy and mountain formation. His most remembered accomplishment is the scientific definition of the Jurassic system ... In the third edition of his On the Origin of Species published in 1861, Charles Darwin added a Historical Sketch giving due credit to naturalists who had preceded him in publishing the opinion that species undergo modification, and that the existing forms of life have descended by true generation from pre-existing forms. According to Darwin: "The celebrated geologist and naturalist, Von Buch, in his excellent 'Description physique des Isles Canaries' (1836, p. 147), clearly expresses his belief that varieties slowly become changed into permanent species, which are no longer capable of intercrossing.' Evolutionary biologist Ernst Mayr has written that Buch was the first naturalist to suggest geographic speciation, in 1825" (Wikipedia). Slight spotting and toning in the outer margins; the portrait itself clean, with a strong imprint.