That there had been cause for alarm, there can be no doubt. That threats should be uttered by the slaves, is natural; for this would be in keeping with their whole history in this country. Nor is it at all improbable that a conspiracy was formed; for this, too, would only be in harmony with the conduct of slaves from time immemorial. The utter folly and hopelessness of such a one as the blacks testified to, has been urged against its existence altogether. If the argument is good for anything, it proves that the conspiracy thirty years before never existed, and that the Southampton massacre was a delusion, and John Brown never hatched his utterly insane conspiracy in Harper's Ferry. There have been a good many servile insurrections plotted in this country, not one of which was a whit more sensible or easier of execution than this, which was said to look to the complete overthrow of the little city. That the fires which first started the panic were the work of negro incendiaries, there is but little doubt; but how far they were a part of a wide-laid plan, it is impossible to determine. Unquestionably, success at the outset would have made the movement general, so that nothing but military force could have arrested it. There is one thing, however, about which there is no doubt--that a panic seized the people and the courts, and made them as unreliable as in the days of the Salem witchcraft. But these striking exhibitions of the weakness of human nature under certain circumstances have been witnessed since the world was made, and probably will continue to the end of time, or until the race enters on a new phase of existence. Panics, even among the most veteran soldiers, sometimes occur, and hence we cannot wonder they take place amid a mixed population. Popular excitements are never characterized by reason and common-sense, and never will be. In this case, there was more reason for a panic than at first sight seems to be.