A writer in the National Intelligencer has commenced a series of essays on the pending controversy between the United States, and the Indians. The first number will be found in our paper this week. As the subject is one of great importance, involving the character of our country, as well as the rights, and happiness, if not the existence, of a brave but unfortunate portion of the human family, we trust they will not prove uninteresting to our readers. It is evident, as the writer remarks, that a crisis is rapidly approaching in the condition of the Indians, particularly of the tribes in the south-western part of the United States. The question must soon be decided, whether they shall be protected in the possession of their lands, and the enjoyment of civil and religious privileges, which, under the policy hitherto pursued towards them by our government, they have learnt to appreciate, or whether they shall be exterminated by their white neighbors, and driven at the point of the bayonet into the wilderness beyond the Mississippi. To this point, we apprehend, the controversy is fast tending. Prompt and efficient protection, or extermination, is the only alternative. For there is evidently a spirit among the whites which will be satisfied with nothing short of the uncontrolled possession of their lands -- and if a force be requisite to obtain them, a pretext will not be wanting. This spirit has been greatly encouraged and sustained by the part taken by the President and Secretary of War, who, in the documents relating to the Indians, recently published, have assumed grounds which, it is believed, are equally repugnant to natural justice and existing treaties. The subject, in some shape, will doubtless soon occupy the attention of Congress, and it is desirable that its merits should be thoroughly investigated and understood by the people at large. It is a subject which no one, we should think, not unconcerned for the character of the country, or insensible to the claims of justice and humanity, can contemplate with indifference.