The settlement of the Indian question so far as it relates to Arizona has been attended with great trouble and expense. Gens. Mason, Gregg, Crittenden, Halleck, Stoneman and McDowell have all attempted a solution, and now Gen. Crook is giving the matter his serious and undivided attention. He is of long and varied experience on the frontier, and has wide knowledge of Indian habits and character; if we are to make war upon the Indians he will be an efficient officer, and probably punish them as severely and thoroughly as any body could. We are not informed to what extent he believes in the President's peace policy, but it is certain that he will not at present tolerate any interference by the Commissioners, and he is represented as saying he can subdue the Apaches in a few months if he is let alone.

We desire peace in Arizona as well as elsewhere on the frontier, and if it can be had in no other way it must be gained by killing the Indian warriors. We are not yet satisfied that this course of procedure is necessary, but the Administration apparently consents to the enforcement of Gen. Crook's views. If the war policy must prevail, let us have war in downright earnest. But war does not mean indiscriminate slaughter. Women and children should not be the persons against whom we take stern measures, nor does the punishment of hostile braves belong to the citizen residents of the Territory. We have heretofore expressed our opinion concerning the Camp Grant and Camp Verde massacres, and since doing so have seen no reason whatever for withdrawing the condemnation to which utterance was given. In response to what was said we have received several letters from Arizona, the longest and most important of which we this week present in full to our readers. It was written by a gentleman of standing and character, and we bespeak for it a candid perusal, as a presentation of the case in issue from the frontier point of view. The writer may be considered as a representative man of those who attempt to justify or excuse the Camp Grant affair.

He says there was an attack on the Indians by a mixed body of Mexicans and Americans, in which a large number were killed, and among them some women and children. The officer commanding at the post reported one hundred and twenty-five killed, of whom all but eight were women and children. To us and Eastern people generally this is not the small matter which it seems to be to our correspondent. That the Apaches are a savage and warlike tribe is well enough known; it is our business as whites, and a part of the President's humane policy, to teach them the arts and methods of civilization; if they decline to go on reservations, and continue to depredate the settlements, and cannot be persuaded to peacefulness, they must suffer for their criminal obstinacy, and in their proper punishment the nation will readily acquiesce. What should have been done in this Camp Grant case? Just what our correspondent says--exactly what was not done. The parties who engage in these massacres, whether of Mexican or New-England birth, are little better than the worst of the Apaches themselves. They have no warrant except that of barbarism for their proceedings, and vastly aggravate the difficulties to be encountered in settling the Indian question.