Definition of "Seishin"

The influx into the Chientao (間島) of Corean farmers, hunters, and trappers had long been a burning question before the Governments of China and Japan finally agreed by the Chientao Convention of 1909 or China-Corean Frontier Agreement to recognize the Tumen river as the boundary between Corea and China, and to open Lungchingtsun (龍井村) along with three other places to foreign residence and trade. A Chinese Custom House was accordingly opened here on 1st January 1910, but was made subordinate to the Hunchun (琿春) Customs.² It remained in this subordinate position till July 1924 when the head office was transferred to Lungchingtsun,³ while Hunchun—at which in accordance with the Manchurian Convention of 1905 a Custom House had been opened on 27th December 1909—fell into the position of a branch office. The reason for this deposition of Hunchun was the advent in 1923 of the T’ien T’u (天圖) light railway which running through Lungchingtsun to Yen Chi Fu (延吉府) connected both places with the frontier district of Kaishantun, and thence through Kainei (Hui Ning 會甯) to the Corean port of Seishin.

1938, Stanley F. Wright, “From the Revision that Failed to the Peking Tariff Conference of 1925-1926”, in China's Struggle for Tariff Autonomy: 1843-1938‎, Paragon Book Gallery, page 406

In May 1939 the first blast furnace of the Mitsubishi Seishin plant started work, while the plant of the Japan Iron Company in Seishin was expected to be ready by April 1941. Thus beside Kenjiho, which for twenty years was the only center of production of pig iron and steel (Mitsubishi, later Nippon Seitetsu), several other centers of production have presumably begun operation, of which the most important is Seishin (a port, about 60 miles from the Russian frontier).

1944, Andrew J. Grajdanzev, “Power and Mineral Resources”, in Modern Korea‎, John Day Company, page 142

Ships and aircraft of the soviet fleet destroyed two Japanese minelayers and 14 transports in forays supporting the landings, Moscow said, and at the same time the port of Seishin, 36 miles southwest of Rashin, was endangered by the advance of soviet troops on the Asiatic mainland.The soviet bulletin said Marshal Kirill A. Meretskov's First Far Eastern army, in a 22-mile advance in Manchuria, had captured the rail town of Hunchun, 37 miles north of Yuki. This swift soviet advance imperiled the junction city of Tumen, 27 miles to the west, which controls the rail routes from central Manchuria to Seishin port.

1945 August 13, “RUSSIAN FLEET LANDS MARINES; TAKES 2 PORTS”, in Chicago Daily Tribune‎, volume CIV, number 103, page 3, column 2