The declining trade, the internal disorganization, and the rapidly augmenting slave population of Bahia, all tend to prove that the system of slavery which the Brazilians consider essential to the welfare of their country, operates directly against her real interests. The wonderful resources of the Brazils will, however, never be fully developed until the Brazilians resolve to adopt the line of policy suggested in Captain Fitzroy's interesting remarks upon this subject. To encourage an industrious native population on the one hand, and on the other to declare the slave-trade piratical, are the first necessary steps in that march of improvement, by which this tottering empire may yet be preserved from premature decay. RESULTS OF SLAVERY. It would, however, be a vain imagination, to suppose that this wiser and more humane determination will be spontaneously adopted by those most implicated in this debasing and demoralizing traffic. Indeed it appears from the best information obtained on the subject, that since the vigilance of our cruizers has comparatively put a stop to the trade on the west coast of Africa--where it has received a great discouragement--it has been greatly extended on the east. Could it but have been foreseen by our Government that their efforts upon the west coast, would in proportion as they were successful, only tend to drive the traders in human flesh to the eastward, it is probable that Mombas would have still been retained under our dominion; for such a possession would have enabled us to exercise an effectual control in that quarter: as it is, it gives additional reason to regret that the place was ever abandoned. The horrors of the passage--horrors which no imagination can heighten, no pen adequately portray--are by this alteration in the chief seat of the accursed trade most fearfully augmented. The poor victims of cruelty and fraud and avarice, in their most repulsive forms, are packed away between decks scarcely three feet high, in small vessels of 30 or 40 tons, and thus situated have to encounter the cold and stormy passage round the Cape: the average mortality is of course most frightful, but the smallness of the vessels employed decreases the risk of the speculators in human flesh, who consider themselves amply repaid, if they save one living cargo out of every five embarked! MORAL CONDITION OF THE NEGROES. In the meantime cargoes of slaves are almost weekly landed in the neighbourhood of Bahia: the thousand evils of the vile system are each day increasing, and with a rapid but unregarded footstep the fearful hour steals on, when a terrible reckoning of unrestrained revenge will repay all the accumulated wrongs of the past, and write in characters of blood an awful warning for the future!