The onrush of the Turks from the Far East into all civilized lands, including China, which continued from the tenth century to the end of the seventeenth, enlarged the meagre Turkish vocabulary. The tribes which invaded India, now known under the name of Moguls, lost their language: hut those which conquered Persia and overthrew the Byzantine Empire came under the literary influence of Persian at first. then of Arabic, and finally of Greek and the European languages. The consequence was that the Otto man Turkish (Osmanli). as the Western branch of the language is called, adopted into its literary vocabulary Persian words for poetry and history, Arabic words for religions and legal writings, Greek words for the winds and currents and fishes of the sea. Italian words for all that relates to sailing vessels, and, later on, English terms for steam, the steamboat and its manoeuvres. and French words for many of the terms of diplo macy.
The language of the Turkish tribes left in Central Asia and Persia and Southern Russia after the centre of the Turkish power had been transferred to Constantinople ceased its develop ment at that point. That language is what is now known as Eastern Turkish. What it was at the end of the fifteenth century, that it is now. The dividing line between Eastern and Western Turkish is the Caucasus, the Caspian Sea, and the western frontier of the Persian Province of Azerbaijan. Beyond the Caspian Sea the dif ference of dialect is so great that a Turk from Bokhara, though able to make his simpler wants known in the streets of Constantinople, requires an interpreter for satisfactory conversation. The
general characteristics of the Eastern Turkish, called Jagaiai by the Turks of Constantinople, are a broader and harsher vocalization, a very confusing substitution of consonants, as in for b, b for w, j for y, etc., and a preservation of those ancient tense and case word-, which in the Western Turkish have become mere arbitrary particles added to the root to indicate tense or case forms. For this reason study of the Eastern Turkish in its purest form, as found, for in stance, in Chinese Turkestan to-day. reveals the processes of evolution of the Turkish grammar. The grammar is practically the same in Turkes tan as in Turkey, but in the East its forms have lost little by attrition. At the same time the unity of the two dialects is clear.
Eastern Turkish has many dialects. The lan guage of sonic of the Kirghizes and that of the Yakuts of the river Lena is strongly tinged with Mongolian, and some Finnish affects the speech of the Tehuvashes of the 'Upper Volga. On the other hand, the Nogai tribes of the Caucasus and the Crimea use a dialect so nearly like the Ottoman Turkish that newspapers published in the Crimea have regular subscribers at Constantinople. The Kiptchak is the only one of these Eastern Turkish dialects which has literary life at present. It is the one, too, which most nearly approaches to the pure type of old Turkish found in the so called Jagatai or Uighur of the East.