We have already intimated that the opinion is prevalent throughout the South that the free States are quite sterile and unproductive, and that they are mainly dependent on us for breadstuffs and other provisions. So far as the cereals, fruits, garden vegetables and esculent roots are concerned, we have, in the preceding tables, shown the utter falsity of this opinion; and we now propose to show that it is equally erroneous in other particulars, and very far from the truth in the general reckoning. We can prove, and we intend to prove, from facts in our possession, that the hay crop of the free States is worth considerably more in dollars and cents than all the cotton, tobacco, rice, hay and hemp produced in the fifteen slave States. This statement may strike some of our readers with amazement, and others may, for the moment, regard it as quite incredible; but it is true, nevertheless, and we shall soon proceed to confirm it. The single free State of New-York produces more than _three times_ the quantity of hay that is produced in all the slave States. Ohio produces a larger number of tons than all the Southern and Southwestern States, and so does Pennsylvania. Vermont, little and unpretending as she is, does the same thing, with the exception of Virginia. Look at the facts as presented in the tables, and let your own eyes, physical and intellectual, confirm you in the truth. And yet, forsooth, the slave-driving oligarchy would whip us into the belief that agriculture is not one of the leading and lucrative pursuits of the free States, that the soil there is an uninterrupted barren waste, and that our Northern brethren, having the advantage in nothing except wealth, population, inland and foreign commerce, manufactures, mechanism, inventions, literature, the arts and sciences, and their concomitant branches of profitable industry,--miserable objects of charity--are dependent on us for the necessaries of life. Next to Virginia, Maryland is the greatest Southern hay-producing State; and yet, it is the opinion of several of the most extensive hay and grain dealers in Baltimore, with whom we have conversed on the subject, that the domestic crop is scarcely equal to one-third the demand, and that the balance required for home consumption, about two-thirds, is chiefly brought from New-York, Pennsylvania and Massachusetts. At this rate, Maryland receives and consumes not less than three hundred and fifteen thousand tons of Northern hay every year; and this, as we are informed by the dealers above-mentioned, at an average cost to the last purchaser, by the time it is stowed in the mow, of at least twenty-five dollars per ton; it would thus appear that this most popular and valuable provender, one of the staple commodities of the North, commands a market in a single slave State, to the amount of seven million eight hundred and seventy-five thousand dollars per annum.