In the eminently original and scientific work of Mr. Colton we see economy subjected to fundamental and ultimate methods of investigation of which the results have a mathematical certainty. We have new facts, new reasonings, new deductions; and if the paramount ideas are not altogether original, they are discovered by original processes, and their previous existence is but an illustration of the truth that the instinctive perspicacity of the common mind often surpasses the logical faculty in recognizing laws before they are discovered from elements and relations. Mr. Colton has not rejected the title "_political_ economy" because he proposed to enter a different field, or because the subject and argument have no relation to politics, but chiefly because the term has been so much abused in the rude agitation of what are commonly called politics, that he does not think it comports with the dignity of the theme; and the second part of his title is adopted from a conviction that the economical principles of states _are to be deduced from their separate experience and adapted to their individual condition_. The task which he proposed to himself is, the exhibition of the merits of the protective and free trade systems as they apply to the United States. He expresses at the outset his opinion that the settlement of the question is one of the most desirable, and will be one of the most important results which remain to be achieved in the progress of the country; and we can assure him that the accomplishment of it will be rewarded by the best approval of these times, and an enduring name. The second chapter of his work is a statement of the new points which it embraces. By new points he does not mean that all thus described are entirely original, though many of them are so; but that on account of the importance of the places he has assigned them as compared with those they occupy in other works of the kind, they are entitled to be presented as new. Many of them involve fundamental and pervading principles that have not hitherto appeared in speculations on the subject, but which are destined to an important influence in its discussion. Some of the most prominent are, that public economy is the application of knowledge, derived from experience, to given positions, interests and institutions, for the increase of wealth; that it has never been reduced to a science, and that the propositions of which it has been for the most part composed, down to this time, are empirical; that protective duties in the United States are not taxes, and that a protective system rescues the country from a system of foreign taxation; that popular education is a fundamental element of public economy; that freedom is a thing of commercial value, and that the history of freedom for all time, shows it to be identical with protection.