[2] In 1891–1892 and 1894, Wichmann studied the Udmurt language as a scholarship holder of the Finno-Ugrian Society.

The topic of his thesis from 1897 was the vowel list of the first syllable of Udmurt compared to the representation of Komi.

In his later travels, Wichmann also studied Komi, Mari and the language of the Csángó Hungarians living in Western Moldavia, Romania.

Wichmann's dictionary of the Csángó dialect was published by Csűry Bálint [hu] and Artturi Kannisto [fi] in 1936.

[2][4] Their son was Väinö Vihma [fi] (1907–1958), professor of commercial law at Helsinki School of Economics.