It is a fact then, which I presume will be new to most of the world, that meat can be cured in the sun without the aid of smoke or salt; and it is a fact equally true and equally surprising also, that none of these tribes use salt in any way, although their country abounds in salt springs; and in many places, in the frequent walks of the Indian, the prairie may be seen, for miles together, covered with an incrustation of salt as white as the drifted snow. I have, in travelling with Indians, encamped by such places, where they have cooked and eaten their meat, when I have been unable to prevail on them to use salt in any quantity whatever. The Indians cook their meat more than the civilized people do, and I have long since learned, from necessity, that meat thus cooked can easily be eaten and relished too, without salt or other condiment. The fact above asserted applies exclusively to those tribes of Indians which I have found in their primitive state, living entirely on meat; but everywhere along our Frontier, where the game of the country has long since been chiefly destroyed, and these people have become semi-civilized, raising and eating, as we do, a variety of vegetable food, they use (and no doubt require), a great deal of salt; and in many instances use it even to destructive excess. LETTER—No. 18. MANDAN VILLAGE, UPPER MISSOURI. The Mandans, like all other tribes, lead lives of idleness and leisure; and of course, devote a great deal of time to their sports and amusements, of which they have a great variety. Of these, dancing is one of the principal, and may be seen in a variety of forms: such as the buffalo dance, the boasting dance, the begging dance, the scalp dance, and a dozen other kinds of dances, all of which have their peculiar characters and meanings or objects.