Wilhelm Gottlieb Tilesius von Tilenau was a German physician, naturalist and explorer. He was in addition a skilled draughtsman and engraver. He was one of three naturalists who participated in a Russian circumnavigation of the globe in 1803-1806, during which he collected plants and other material.
Tilesius was born in Mülhausen, Thuringia. His father was an actuary and merchant. Tilesius studied natural sciences and medicine at Leipzig from 1790, qualifying as doctor of medicine in 1801. During this period he made a journey to Portugal with scientist J.C. Hoffmannsegg, where they made studies of zoology and local medical practice.
In 1803 Tilesius was invited to join Admiral Adam Johann von Krusenstern's circumnavigation of the globe, along with fellow scientists G.H. von Langsdorff and J.G. Horner. The principal object of the voyage was to visit Russian possessions on the north-west coast of America and to open commercial relations with Japan, though scientific collections and observations would also be made. The expedition set off from Kronstadt in August 1803 and picked up Tilesius in Copenhagen.
The expedition's two ships, the Nadezhda and Neda called in at the Canary Islands and Santa Catharina, Brazil, before rounding Cape Horn and heading to Petropavlosk in Kamchatka, which they reached one year after their departure from the opposite side of the country. Following a short stay, the party travelled on to Japan, landing at Nagasaki in October. The ships remained here until April 1805, then returning to Petropovlavsk.
Langsdorff quit the expedition at this point, in June 1805, and made an impressive solo journey to America, returning to St. Petersburg by way of Siberia.
After surveying the Sakhalin region, Krusenstern's expedition travelled on to China and Taiwan, setting anchor at Macao in November 1805. They were hosted here by J. Drummond, President of the East India Company factory. Tilesius made many drawings and watercolours during this stay.
The ships left China in February 1806 and reached Kronstadt in August. An account of the expedition was published by Kronstadt as Reise um die Welt 1803-1806 (3 vols, 1810-1812). Meanwhile, Tilesius was elected Member of the Russian Academy and was made a Knight of the Order of St. Vladimir. His own illustrated report from the expedition appeared in 1814 and his botanical collections were acquired by C.F. von Ledebour and E.L. von Fischer. They were later deposited at the Botanical Garden in St. Petersburg. Among them were Artemisia sachaliensis Tiles. ex Besser, discovered by Tilesius on the eastern coast of Sakhalin in 1805 (he is thus credited with being the earliest botanical collector there), Artemisia tilesii Ledeb. and Serratula tilesii Ledeb. He also collected marine algae, especially in the Korea Strait and East China Sea.
Tilesius married Olympia von Sitzky in 1807, with whom he had a son, though the couple separated shortly afterward. While in Russia, Tilesius reconstructed the skeleton of a woolly mammoth excavated from the Siberian permafrost. Bretschneider claims that Tilesius never visited Siberia himself, however.
Tilesius returned to Germany in 1814 and lectured on zoological and medical subjects at the University of Leipzig, and also in Goettingen and Dresden. He published many papers on fish, whales and invertebrates, and from 1830 concentrated on medical subjects, including cholera. Note that he did not use the suffix von Tilenau in his publications. He spent most of his later life in Mülhausen, where he died in 1857.
Sources:
J. De Bersaques, 2011, "Wilhelm Gottlieb Tilesius - a forgotten dermatologist", JDDG: Journal der Deutschen Dermatologischen Gesellschaft, 9: 563-570
E. Bretschneider, 1898, History of European Botanical Discoveries In China 314-316
D.M. Damkaer, 2002, The Copepodologist's Cabinet: A Biographical and Bibliographical History 1: 156-157.
