Thanks for "people psychology", which in his opinion corrects some wrong ideas, especially in linguistics. Together with his friend [Diedrich] Westermann he made discoveries about the relationship of Sudanese languages. Makes remarks about sound pictures in the Bantu. Has begun work on a Bantu grammar. In contrast to Wundt, he does not necessarily see the cause for sound shifts in cultural progress and refers to his own essay on the subject.

Annual reports, by August Carl Heinrich Kuhlmann, 1913-1940; Briefe d. Elders of the Bergdamra and Herero Communities for the Protection of August Carl Heinrich Kuhl-mann against Defamation, 1913; Visitation Report, 1914