AIGUN (49° 58' N. 127° 35' E.) a treaty port on the south bank of the Amur in Northern Manchuria on the extreme north eastern frontier of China. It lies on the opposite bank to, but about 20 miles below, the Russian city of Blagovyeshchensk, for which it serves as an entrepot. Its trade is concerned primarily with the shipping of Mongolian cattle and meat and Manchurian grain and flour across the river to Blagovyeshchensk. But, since it was burnt down in 19oo during the Boxer troubles, this func tion has passed to Ta-hei-ho T'an which lies immediately opposite Blagovyeshchensk. The trade of Aigun is becoming more and more local and what general traffic it once had has been diverted from the Amur to the Chinese Eastern railway which offers a more direct route between Manchuria and the better-peopled parts of Siberia. Its total trade in 1926 amounted to Hk.Tls. 2,069,279. The Treaty of Aigun (1858) was one of a series of treaties which attempted to define the boundaries between the Chinese and Russian Empires.