One of the interesting events of Southgate's life was a rather intense dispute he had with some Congregationalist and Presby missionasries from the ABCFM, which is the grand-daddy of all American mission boards.
Southgate was sent out by the Episcopal Mission Board in the 1840's, and eventually got into deep trouble because he read some sensitive material written by an ABCFM missionary to an Armenian Christian. It was about how a division in the Armenian Catholic Church (non-Chalcedonian Orthodox, for all you church history nerds out there) would be desirable.
Obviously, this caused a big stir. In a very obscure article which I wanted to bring to light in this post, a detailed description of the entire ordeal is giving. The article on the whole is very critical of Southgate. He did make a big mistake reading that material to an Armenian Christian in the Ottoman Empire, I suspect, but in the end the article's author finds fault with him for being high church Episcopalian.
Interesting article, if a bit long-winded. No author is given.
Tyler, Edward R, et al, eds. 'Bishop Southgate and Episcopal Missions' 1845. The New Englander and Yale Review. Vol 3:2, Pp 244-272.