There can be no doubt whatever that the Koraks and the powerful Siberian tribe known as Chukchis (or Tchucktchis, according to Wrangell) descended originally from the same stock, and migrated together from their ancient locations to the places where they now live. Even after several centuries of separation, they resemble each other so closely that they can hardly be distinguished, and their languages differ less one from the other than the Portuguese differs from the Spanish. Our Korak interpreters found very little difficulty in conversing with Chukchis; and a comparison of vocabularies which we afterward made showed only a slight dialectical variation, which could be easily accounted for by a few centuries of separation. None of the Siberian languages with which I am acquainted are written, and, lacking a fixed standard of reference, they change with great rapidity. This is shown by a comparison of a modern Chukchi vocabulary with the one compiled by M. de Lesseps in 1788. Many words have altered so materially as to be hardly recognisable. Others, on the contrary, such as "tin tin," ice, "oottoot," wood, "weeñgay," no, "ay," yes, and most of the numerals up to ten, have undergone no change whatever. Both Koraks and Chukchis count by fives instead of tens, a peculiarity which is also noticeable in the language of the Co-Yukons in Alaska. The Korak numerals are:-- Innín, One. Née-ak°h, Two. Nee-ók°h, Three. Née-ák°h, Four. Míl-li-gen, Five. In-nín míl-li-gen, Five-one. Née-ak°h " Five-two. Nee-ók°h " Five-three. Née-ák°h " Five-four. Meen-ye-geet-k°hin, Ten. After ten they count ten-one, ten-two, etc., up to fifteen, and then ten-five-one; but their numerals become so hopelessly complicated when they get above twenty, that is would be easier to carry a pocketful of stones and count with them, than to pronounce the corresponding words. Fifty-six, for instance, is "Nee-akh-khleep-kin-meen-ye-geet-khin-par-ol-in-nín-míl-li-gen," and it is only fifty-six after it is all pronounced! It ought to be at least two hundred and sixty-three millions nine hundred and fourteen thousand seven hundred and one--and then it would be long. But the Koraks rarely have occasion to use high numbers; and when they do, they have an abundance of time. It would be a hard day's work for a boy to explain in Korak one of the miscellaneous problems in Ray's Higher Arithmetic. To say 324 × 5260 = 1,704,240 would certainly entitle him to a recess of an hour and a reward of merit. We were never able to trace any resemblance whatever between the Koraki-Chukchi language and the languages spoken by the natives on the eastern side of Bering Strait. If there be any resemblance, it must be in grammar rather than in vocabulary.