Postels studied at
St.Petersburg Imperial University and in 1826 lectured there on
inorganic chemistry. In the 1820s political relations between
Russia and the United States were troubled by the extent of Russian territory in North America. Russia intended to enforce its claims by sending two warships to the disputed areas. When the two countries agreed on 54°40′N as the southern limit of Russian claims, Tsar
Nicolas I changed their orders in 1826 to an extended three-year survey of the Russian-American and Asian coasts.
Otto von Kotzebue had returned on 10 July 1826 from his voyage of discovery aboard
Predpriyatiye. On 16 August 1826, Captain Lieutenant
Fedor Petrovich Litke, sailed on board the Russian vessel
Senyavin, accompanied by the
Möller under Captain Lieutenant
M. N. Staniukovich. Postels sailed with Litke as a naturalist/artist and had the distinction of being the first St. Petersburg University graduate to join such a large-scale expedition. On board were also the naturalist
Karl Heinrich Mertens (1796–1830), who died in Kronstadt shortly after his return from
Iceland and another trip on the
Senyavin, and the ornithologist
Baron von Kittlitz. Their orders were to: The expedition sailed from
Kronstadt, the Russian port on
Kotlin Island, via
Portsmouth and rounded
Cape Horn on 24 February 1827. The
Senyavin called at
Concepcion in
Chile, before sailing north to
Sitka, and arriving at
Petropavlovsk in mid-September. They explored the
Caroline Islands and the
Bonin-Jima group for four months, returning to Kamchatka in May. During the summer they sailed from
Avacha Bay to Karaginskii Island and on through the
Bering Strait to reconnoitre the coast as far north as the
Anadyr River. They returned via
Manila and the
Cape of Good Hope, arriving back in
Kronstadt on 16 September 1829. The expedition was called the largest and most productive voyage of discovery of the era, and brought back some 4 000 natural history specimens, including mammals, insects, birds, plants, and minerals. More than 1250 sketches of their findings were made on the voyage. Twelve island groups were discovered along the Asian coast, and 26
Caroline Islands were explored and described. The flattening of the Earth's poles was investigated using an
invariable pendulum. Postels was appointed assistant-professor of the Department of Mineralogy and Geology of St.Petersburg University. During the voyage Postels depicted more than 100
seaweeds or marine algae from the northern Pacific in
"Illustrationes algarum in itinere circa orbem jussu Imperatoriis Nicolai I" published in
St. Petersburg in 1840. The seaweed genus
Postelsia is named in his honour. This botanist is denoted by the
author abbreviation Postels when
citing a
botanical name. Postels was elected an Honorary Member of the
Russian Academy of Sciences on 14 January 1866 and invited to act as curator of the Mineralogical Museum. He tutored the Grand Duchesses Maria and
Ekaterina, daughters of Tsar Nicolas I's brother
Mikhail, and was the tutor of
Prince Oldenburgski's children. ==See also==