The free soil party have been plain and explicit as the democrats; they published their creed in the celebrated Buffalo platform. The questions of sub-treasury and tariff are set aside; "No more slave territory" is the watchword. In part they represent an interest, for slavery is an injury to the North in many ways, and to a certain extent puts the North into the hands of the South; but chiefly an idea. Nobody thought they would elect their candidate, whosoever he might be; they could only arrest public attention and call men to the great questions at issue, and so, perhaps, prevent the evil which the South was bent on accomplishing. This they have done, and done well. The result has been highly gratifying. It was pleasant and encouraging to see men ready to sacrifice their old party attachments and their private interests, oftentimes, for the sake of a moral principle. I do not mean to say that there was no moral principle in the other parties--I know better. But it seems to me that the free soilers committed a great error in selecting Mr. Van Buren as their candidate. True, he is a man of ability, who has held the highest offices and acquitted himself honorably in all; but he had been the "Northern man, with Southern principles;" had shown a degree of subserviency to the South, which was remarkable, if not singular or strange: his promise, made and repeated in the most solemn manner, to veto any act of Congress, abolishing slavery in the capital, was an insult to the country, and a disgrace to himself. He had a general reputation for instability, and want of political firmness. It is true, he had opposed the annexation of Texas, and lost his nomination in 1844 by that act; but it is also true that he advised his party to vote for Mr. Polk, who was notoriously in favor of annexation. His nomination, I must confess, was unfortunate; the Buffalo Convention seems to have looked at his availability more than his fitness, and, in their contest for a principle, began by making a compromise of that very principle itself. It was thought he could "carry" the State of New York; and so a man who was not a fair representative of the idea, was set up. It was a bad beginning. It is better to be defeated a thousand times, rather than seem to succeed by a compromise of the principle contended for. Still, enough has been done, to show the nation that the dollar is not almighty; that the South is not always to insult the North, and rule the land, annexing, plundering, and making slaves when she will; that the North has men who will not abandon the great sentiment of freedom, which is the boast of the nation and the age.