Note 059
From Chapter 13 of the Decline & Fall

Vou-ti, the first emperor of the seventh dynasty, who then reigned in China, had political transactions with Fergana, a province of Sogdiana, and is said to have received a Roman embassy (Histoire des Huns, tom. i. p. 38). In those ages the Chinese; kept a garrison at Kashgar, and one of their generals, about the time of Trajan, marched as far as the Caspian Sea. With regard to the intercourse between China and the western countries, a curious memoir of M. de Guignes may be consulted, in the Academie des Inscriptions, tom. xxii. p. 355