a large river of European Russia, the principal affluent of the Volga. It rises in the government of Viatka, N.E. of Glazov, flows first N. and then N.E. into the government of Perm, where it takes a S.W. direction; it afterwards separates the government of Viatka from those of Perm and Orenburg, and, entering Kasan, joins the Volga, after a course of more than 100 miles. One of its affluents is connected with an affluent of the Dwina by a canal 12 miles in length, thus establishing water communication between the White Sea and the Caspian.