Walter Henry Medhurst and Robert Morrison were London Missionary Society (LMS) colleagues and friends.

In an 1817 letter, Morrison told the LMS directors that Medhurst had sent a promising specimen of small metal types, intended for magazines and tracts, and said the "qualifications and attention of Mr. M. give us great satisfaction".

[4] As Medhurst explained in an 1841 letter to the LMS directors, his motivation to produce a Chinese and English dictionary came from Morrison's expensive one, which the missionary school's students could not afford.

He said his "compendious and cheap" dictionary would contain "every character in Morrison's with all of the useful phrases, in one volume at the moderate cost of a few dollars".

The dictionary includes 20 initials, and Medhurst adopted Morrison's method of using apostrophes to represent the unaspirated-aspirated stop consonant pairs (listen to examples here).

The 55 finals are also explained, for example,[10] the rhotic coda or r-colored vowel /ɚ/, which is difficult for many non-native speakers.

The LMS had previously used small type to print Christian translations and tracts that were smuggled into China, where they were forbidden.

[13] For the bilingual sources of his English–Chinese dictionary, Medhurst says he extracted "all that he thought serviceable from Morrison" and an anonymous Latin-Chinese manuscript dictionary—presumably the Italian Franciscan Basilio Brollo's (1698) Dictionarium Sino-Latinum—"while he flatters himself that he has gone far beyond either of his predecessors, in the amount of foreign words adduced, and of expressions brought together to elucidate them.".

On the one hand, the reviewer praises the dictionary's portability and price, "two octavo volumes containing 1500 pages for ten dollars", but on the other, expresses regret that Medhurst "has said so little on the subject of tones" other than "that he considers them of paramount importance".

[19] Williams explicitly identified "Dr. Medhurst's translation of the K'anghi Tsz'tien" as a more important source for his own work than Morrison's dictionary.

[20] The preface to the British diplomat and sinologist Herbert Giles's A Chinese–English Dictionary[21] praised Morrison as "the great pioneer" of Chinese and English lexicography, but criticized his failure to mark aspiration.

Huiling Yang, a researcher at Beijing Foreign Studies University, expresses surprise that the Chinese and English Dictionary, which Medhurst claimed to be his translation based on Kangxi zidian, "is in fact just an abbreviated and edited copy of Morrison’s, a plagiarism rather than an original compilation".