[2] While working on this job, in 1866 he published a monograph on the Tiandihui (Heaven and Earth Society)—the first on the topic in Dutch—, and another one on prostitution in Canton.

[3] In 1869 he was awarded a doctorate from the University of Jena; his thesis was on the customs and pastimes of the Chinese,[1] but this writing was apparently a formality because his reputation had been established by his previous publications.

Schlegel accepted, and in 1873 he pursued the matter further writing a pro domo letter to the Colonial Minister, asking for the government to establish a university position.

[3] Schlegel's 1866 monograph on the Heaven and Earth Society is considered the major breakthrough in its study, even in 21st century scholarship.

Although the German press even bracketed this work in the same category of achievements as the Forth Bridge and the Eiffel Tower, it had little impact outside Dutch sinology.

)[3] Perhaps Schlegel's most lasting contribution is the founding in 1890, together with Henri Cordier, of the journal T'oung Pao, providing a joint publishing venue for the then leading Sinological centers of Europe.

[7] Schlegel also wrote extensively on the geographical accounts found in Chinese historical texts like the Book of Liang.