This locust-like progress of the American settler--ever on the move to new lands, and leaving comparative barrenness in his track--must evidently place the case of America beyond the sphere of those ordinary laws of political economy which are applicable in European countries; and Professor Johnston seems to consider the fact of the incessant exhaustion and abandonment of lands as the chief key to a right understanding of the peculiar economical position of the United States. The owner of land in the older and more populous States, who has not learnt to apply a restorative system of culture, derives little benefit from the comparative advantage of situation, while the inhabitants of the towns and villages around him are fed with the surplus spontaneous produce of the far off clearings in Ohio or Missouri. But these in their turn become worn out--and as cultivation travels on westward, the chief centres of agricultural production are gradually receding farther and farther from the chief centres of population and consumption; and this increasing distance, and consequent cost of transport, is every year enhancing the price of grain in the busy and crowded marts of the West--ever filling up with the incessant stream of immigration from Europe. Such is Mr Johnston's view of the present normal condition of the Union in regard to the sustenance of her people; and he makes it the ground-work, as we shall presently see, of certain rather doubtful inferences, of some importance in their bearing on the agriculture of this country. One consequence, however, of any material increase in the price of food in the Eastern States of the Union is very obvious--the proprietor of land in these districts will gradually be enabled to apply, with profit to his exhausted soil, the artificial aids and costlier system of culture followed in Britain. Already this result is apparent in Professor Johnston's account of the energetic spirit of agricultural improvement which is rapidly spreading over most of the New England States. In the keen, restless, and enterprising New Englander, our Old Country farmers will undoubtedly find a more formidable competitor, for the honour of the first place in agricultural advancement, than any they have yet met on this side of the Atlantic. We have seen this year what his invention can produce in mechanical contrivances for economising the labour of the field; and, that he is not indifferent to the aids which science can afford him, is sufficiently proved by the occasion of that visit to America of which Professor Johnston has here given so pleasant and instructive a record. The invitation was not more creditable to the character of the Professor, than to the discernment of the zealous and patriotic men who thus showed how correctly they apprehend the true method of improving their fine country. His engagement was fulfilled during the sitting of the State Legislature at Albany in January 1850, when the hall of the