'Phags-pa script
Although he did not actually publish anything relating to the 'Phags-pa script, during his time in China (probably on his 1872 trip to Inner Mongolia) he acquired the only extant manuscript copy of the early 14th century rhyming dictionary of Chinese written in the 'Phags-pa script ("Menggu Ziyun" 蒙古字韻), which was sold to the British Museum by his widow in April 1909. This is the only surviving example of a dictionary written in the 'Phags-pa script, and is the single most important source for studying how Chinese was written in the 'Phags-pa script during the Yuan dynasty. This manuscript is now held at the British Library (callmark Or. 6972).