It has seemed necessary to make the most additions to the original treatise under the subjects of the Wages Question; of Wages of Superintendence; of Socialism; of Cost of Production; of Bimetallism; of the Paper Money experiments in this country; of International Values; of the Future of the Laboring-Classes (in which the chapter was entirely rewritten); and of Protection. The treatment of Land Tenures has not been entirely omitted, but it does not appear as a separate subject, because it has at present less value as an elementary study for American students. The chapters on Land Tenures, the English currency discussion, and much of Book V, on the Influence of Government, have been simply omitted. In one case I have changed the order of the chapters, by inserting Chap. XV of Book III, treating of a standard of value, under the chapter treating of money and its functions. In other respects, the same order has been followed as in the original work. To interest the reader in home problems, twenty-four charts have been scattered throughout the volume, which bear upon our own conditions, with the expectation, also, that the different methods of graphic representation here presented would lead students to apply them to other questions. They are mainly such as I have employed in my class-room. The use and preparation of such charts ought to be encouraged. The earlier pages of the volume have been given up to a “Sketch of the History of Political Economy,” which aims to give the story of how we have arrived at our present knowledge of economic laws. The student who has completed Mill will then have a very considerable bibliography of the various schools and writers from which to select further reading, and to select this reading so that it may not fall wholly within the range of one class of writers. But, for the time that Mill is being first studied, I have added a list of the most important books for consultation. I have also collected, in Appendix I, some brief bibliographies on the Tariff, on Bimetallism, and on American Shipping, which may be of use to those who may not have the means of inquiring for authorities, and in Appendix II a number of questions and problems for the teacher's use.