He served in Evangelical Church of Württemberg as pastor. Adopting a Chinese name , he later came to Lilang, Xin'an district in Guangdong, China under the Basel Mission. In April 1865 he transferred to the London Missionary Society at Guangzhou to take in charge of the Boluo Mission and the Hakka villages outside Guangzhou. In January 1870 he moved to Hong Kong while still having charge of the Boluo Mission. In 1875 he became Director of Chinese Studies. In April 1879 he resigned from the London Missionary Society.
He then became Inspector of Schools in Hong Kong and later Chinese Secretary to Sir John Pope Hennessy. In 1866 he married Mary Anne Winifred Eaton of the Female Education Society. He died in Adelaide, Australia, in 1908.
A Cantonese Dictionary
Eitel has published its dictionary, ''Chinese Dictionary in the Cantonese Dialect'' in 1877. It is based on a Cantonese glossary dictionary ''Tonic Dictionary of the Chinese Language in the Canton Dialect'' written in 1856 by Samuel Wells Williams, expanding with the work of James Legge and ''Kangxi Dictionary''. His publication was intended to standardize the pronunciation of Cantonese.
His work was criticised by Wong Shik Ling in the book ''A Chinese Syllabary Pronounced according to the Dialect of Canton'' that it inherited the inaccuracy from former works.
* ''Feng-Shui, Or, The Rudiments Of Natural Science In China''
* ''A Chinese dictionary in the Cantonese dialect''
* ''The central school : can it justify its raison d'etre?''
* ''Buddhism : its historical, theoretical and popular aspects''
* ''Chinese School-Books''
* ''Europe In China : The History Of Hong Kong From The Beginning To The Year 1882''