The more the necessity for exhausting land and for selling negroes, the cheaper, however, will be wheat and cotton. Uncle Tom might have remained at home had the powers of the land been maintained and had Virginia been enabled to avail herself of her vast resources in coal, iron ore, water-power, &c.; but as she could not do this, he had to go to Arkansas to raise cotton: and the larger the domestic slave trade, the greater must be the decline in the price of that great staple of the South. At no period was that trade so large as in that from 1830 to 1840, and the effects are seen in the following comparative prices of cotton:-- Crops, 1831 and 1832, average 10-1/2. 1841 and 1842, average 7. The export of negroes declined between 1842 and 1850, and the consequence is that cotton has since maintained its price. With the closing of Southern mills the slave trade, is now again growing rapidly, and the consequences will be seen in a large decline in the price of that important product of Southern labour and land. The reader will now observe that it was in the period from 1830 to 1840 that the tendency to emancipation disappeared--that it was in that period were passed various laws adverse to the education of negroes--that it was in that period there was the greatest enlargement of the domestic slave trade--and the greatest decline in the price of cotton. Having remarked these things, and having satisfied himself that they, each and all, have their origin in the fact that the planter is compelled to depend on foreign markets and therefore to exhaust his land, he will be enabled to judge of the accuracy of the view contained in the following sentence :-- "The price of a negro on Red River varies with the price of cotton in Liverpool, and whatever tends to lower the value of the staple here, not only confers an inestimable advantage on our own manufacturing population, but renders slave labour less profitable, and therefore less permanent in Alabama."--_Prospective Review_, No. xxxii. 512. It would be fortunate if philanthropy and pecuniary profit could thus be made to work together, but such unhappily is not the case. When men are enabled to come nearer to each other and combine their efforts, and towns arise, land acquires great value and gradually becomes divided, and with each step in this direction the negro loses his importance in the eye of his owner. When, however, men are forced to abandon the land they have exhausted, it becomes consolidated, and the moveable chattel acquires importance in the eyes of his emigrant owner. At death, the land cannot, under these circumstances, be divided, and therefore the negroes must; and hence it is that such advertisements as the following are a necessary consequence of the system that looks to cheap wheat, cheap sugar, and cheap cotton. HIGH PRICE OF NEGROES.--We extract the following from the Lancaster (S. C.) _Ledger_ of the 5th January last:--