In Burma, besides conducting a training college for native preachers and teachers at Tavoy, he translated the Bible into the two principal dialects of the Karens, the Sgaw and the Pwo (his translation being published in 1853), and Matthew, Genesis, and the Psalms into the Bghai dialect. He also published A Pali Grammar on the Basis of Kachchayano, with Chrestomathy and Vocabulary (1868). In 1849, he described a new species of pine, Tenasserim Pine in the journal of the Asiatic Society. In 1850 he published a book of great value on the fauna and flora of British Burma titled The natural products of Burmah, or notes on the fauna, flora and minerals of the Tenasserim provinces, and the Burman empire. It was published by the American Mission Press at Moulmein. An improved edition appeared in 1860 under the title Burmah, its People and Natural Productions, and a third edition (2 vols.) revised and enlarged by William Theobald in 1882-1883.
He was a Freemason and briefly faced exclusion from his missionary work due to certain views held by his wife, one of them being that God's way of speaking to Adam was revealed in the designs of the Burmese women's dresses. He died at Rangoon. See his autobiography, The Story of a Working Man's Life, with Sketches of Travel in Europe, Asia, Africa and America (New York, 1870).