Page:Popular Science Monthly Volume 52.djvu/438

422 part, comprising seventy-eight pages, is devoted to a consideration of methods, and is much the more important portion from a popular standpoint, because it really amounts to a discussion of the legitimacy of psychology as an experimental and exact science. The second part discusses "time" in its various psychological aspects. In Parts III and IV energy and space are respectively taken up. It will be seen from these headings that there is an attempt to divide the subject in a way analogous to that used in the study of physics. The last thirty pages of text, entitled Past and Present, give a brief history of the methods, speculations, and men connected with the study of psychology since the days of the Greeks. The book contains numerous drawings and illustrations, and several useful tables and formulæ, as appendices.

Mr. Bullock's Introduction to the Study of Economics fulfills well the exact purpose implied in its title. The first three chapters—which relate to the growth of the United States and their population, their land tenures and systems of labor, the growth of their foundational institutions, of the fur trade, cattle raising, fisheries, and mining, and manufactures and transportation—aim to familiarize the student with an orderly treatment of some leading facts in the economic history of the United States before the study of economic theory is begun. Throughout the book economic principles are discussed with special reference to American conditions, and their workings are illustrated by frequent allusions to American experience. The subjects of wealth, its consumption, production, and distribution, exchange, money, credit, bimetallism, monopolies, international trade, wages, land nationalization and socialism, and the economic functions of Government are thus treated; while public finance has been only incidentally touched upon, and it has not been considered expedient to attempt to discuss taxation within the special limits of the volume. We have been much struck with the clear presentation made of principles and doctrines, of the strong common sense that pervades the author's observations, and the general soundness of his views. A bibliography of the special subject is given at the close of each chapter, and a general bibliography of twenty-five pages and a copious index will be found at the end of the book.

The Natural History of the Concise Knowledge Library is an admirable example of the manner in which much information may be presented satisfactorily in a small space. It is a book that may be held in the hand and is legibly printed, yet it covers the whole animal kingdom, and each department is treated by an expert in it, distinguished as an authority and an original investigator. It well fulfills its aim, as defined in the preface, to be concise and popular, at once accurate in statement, handy in form, and ready of reference. While giving all the technical names, the authors have sought to express themselves as much in English as possible. Hence in the text the technical terms are rendered in their English equivalents, or, where there are none such, explained in the vernacular in such a way that the most unlearned may understand what is meant. Mr. Lydekker even goes so far as to apologize for using so little technical a word as "mammals," because it has no English equivalent, "beasts" excluding man, and quadrupeds excluding man and the higher apes, and including lizards, etc. The text is preceded by a concise systematic index, giving the complete classification, and followed by an alphabetical index, containing about ten thousand references and occupying forty-six pages.

The rapid onward march of science has made necessary the revision of what was a thoroughly up-to-date book on optics fifteen years ago. The changes we find in the new edition of Professor Le Conte's "Sight," are mainly in the form of additions. The principal of these are in Part I: a fuller