only mention one other fact, which seems in itself a sufficient refutation of the theory Professor Johnston has taken up. The causes which he thinks are so soon to dry up the supplies now derived from the West are of no recent or sudden emergence. The process of exhaustion on the new lands, and the rapid population of the old, has been going on for many years. If, then, these causes are so influential as he imagines, their effects should at least be apparent in a gradual increase of the prices of bread-stuffs in the Eastern States. Now, no such effect is to be found. On the contrary, we find that, during the last twenty years, the price of wheat, as well as of maize, in the chief marts of the east, has been _steadily diminishing, instead of increasing_. We extract from the returns published by the Board of Trade the annexed comparison[3] of the prices of wheat flour at New York, during two periods, from which it appears that, in the very State where the results of Professor Johnston's hypothesis ought to have been most manifest, the experience of twenty years shows a reduction of price instead of an enhancement, notwithstanding that the latter period in the comparison embraces the years of the potato failure. An examination of similar returns from Baltimore and New Orleans establishes the same fact, namely, that the tendency of prices for twenty years past is _not upwards, but downwards_--a fact quite irreconcilable with the supposed rapid exhaustion of the wheat soils of the interior. [1] The estimated produce of wheat in these five States in the year 1847 was 38,400,000 bushels. [2] Quantity of bread-stuffs exported from the whole of the United States, and from the ports of New York and Philadelphia, in the years 1842-46 inclusive:-- | Wheat | Flour | Indian Corn | Indian Corn | (bushels.) |(barrels.) | (bushels.) |(Meal barrels.) |------------+-----------+-------------+--------------- United States, | 2,691,711 | 7,048,356 | 4,764,450 | 1,199,255 |------------+-----------+-------------+--------------- New York, | 1,985,900 | 2,610,944 | 2,443,733 | 242,294 Philadelphia, | 474,788 | 1,055,382 | 677,530 | 565,682 |------------+-----------+-------------+--------------- Total of both ports, | 2,460,688 | 3,666,326 | 3,121,263 | 807,976 [3] Comparative statement of the prices, per barrel, of best wheat flour at New York, (taken from the _Monthly Averages_) in 1829-33, and 1844-48:-- FIRST PERIOD. 1829, Dr. 6.23 1830, 5.02 1831, 5.84 1832, 5.70 1833, 5.70 ---- Average of five years, 5.69 SECOND PERIOD.