No sooner had he recovered from the illness which his last journey had occasioned than he set out, under the auspices of the Academy of St Petersburg and the Alexander University, on an exploration among the Indigenous peoples of Siberia, which resulted in a vast addition to previous knowledge, but seriously affected the health of the adventurous investigator. The first fruits of his collections were published at St. Petersburg in 1849 in the form of a "Versuch einer ostjakischen Sprachlehre". In 1850 he published a treatise "De affixis personalibus linguarum Altaicarum", and was appointed professor of the new chair of Finnish language and literature at the University of Helsinki. The following year saw him raised to the rank of chancellor of the university. He was busily engaged in what he regarded as his principal work, a grammar of the Samoyedic languages, when he died in 1852 at 38 years of age.