We must examine, more closely, the economical results of emancipation, in the West Indies, before we can judge of the effects, upon the trade and commerce of the world, which would result from general emancipation in the United States. We do this, not to afford an argument in behalf of the perpetuation of slavery, because its abolition might injuriously affect the interests of trade and commerce; but because the whole of these results have long been well known to the American planter, and serve as conclusive arguments, with him, against emancipation. He believes that, in tropical cultivation, African free labor is worthless; that the liberation of the slaves in this country, must, necessarily, be followed with results similar to what has occurred in the West Indies; and, for this reason, as well as on account of the profitable character of slavery, he refuses to give freedom to his slaves. We repeat, we do not cite the fact of the failure, economically, of free labor in Jamaica, as an argument for the perpetuation of slavery. Not at all. We allude to the fact, only to show that emancipation has greatly reduced the commerce of the colonies, and that the logic of this result militates against the colored man's prospects of advancement in the scale of political and social equality. But to the facts: The British planters, up to 1806, had received from the slave traders an uninterrupted supply of laborers, and had rapidly extended their cultivation as commerce increased its demands for their products. Let us take the results in Jamaica as an example of the whole of the British West India islands. She had increased her exports of sugar from a yearly average of 123,979,000 lbs. in 1772-3, to 234,700,000 lbs. in 1805-6. No diminution of exports had occurred, as has been asserted by some anti-slavery writers, before the prohibition of the slave trade. The increase was progressive and undisturbed, except so far as affected by seasons, more or less favorable. But no sooner was her supply of slaves cut off, by the act of 1806, which took effect in 1808, than the exports of Jamaica began to diminish, until her sugar had fallen off from 1822 to 1832, to an annual average of 131,129,000 lbs., or nearly to what they had been sixty years before. It was not until 1833 that the Emancipation Act was passed; so that this decline in the exports of Jamaica, took place under all the rigors of West India slavery. The exports of rum, coffee, and cotton, were diminished in nearly the same ratio.