synthetic grasp, which leads him to take large views, and treat the subjects he enters upon with comprehensiveness. The opening and closing papers of the present volume—the first, "On the Relation of Natural Science to Science in General," and the last, "On the Aim and Progress of Physical Science"—are admirable examples of this broad judicial treatment of the subjects discussed. His statement of the reactions of science and philosophy in Germany, and the influence of the German universities upon contemporary thought, in the first paper, is especially admirable. The volume also contains very able articles upon his special subjects of investigation—one "On the Physiological Causes of Harmony in Music," and another elaborate paper, in three parts, "On the Recent Progress of the Theory of Vision." There is also a very interesting lecture "On Goethe's Scientific Researches," and an elaborate discussion of glacial phenomena. Two papers are also given "On the Interaction and Conservation of Forces," a subject which Prof. Helmholtz has pursued independently, and which in these expositions is presented in its fundamental principles. Numerous illustrations enhance the instructiveness of the volume, which, though compactly written, is still remarkably clear in its explanations. Prof. Helmboltz is an eminent master of the art of statement, but, as his thoughts appear in a foreign language, the force and finish of the original composition are not to be looked for. Yet the several translations of this volume by Professors Eve, Ellis, Atkinson, Tyndall, and Drs. Flight and Pye-Smith, have been made with great care, so that the work is as attractive and readable in style as it is solid and instructive in its thought. We commend this book to all who are interested in the higher scientific problems of the age, as treated by one of its master-minds.
The Mineral Springs of the United States and Canada, with Analyses and Notes of the Prominent Spas of Europe, and a List of Sea-side Resorts. By George E. Walton, M. D. New York: D. Appleton & Co.
The author of this work seems at first to have been sorely perplexed as to whether there are or are not any medicinal virtues in mineral waters. The public is inclined to be credulous in regard to their remedial uses, and the medical profession is inclined to be skeptical about them. In point of fact, great numbers of people with divers ailments seek the mineral fountains of various localities, and use them very much at hap-hazard. At the same time he says that, while the American profession is inclined to be incredulous as to the medical services of these springs, eminent European physicians, such as Trousseau and Niemeyer, assign an important place to mineral waters in the treatment of many chronic diseases. In this unsatisfactory state of opinion, Dr. Walton entered systematically upon the inquiry as to the remedial uses of the mineral waters of the United States and Canada, and in the volume now printed he has endeavored to arrange all the known facts concerning them in such a manner that they shall be readily accessible, and serve to guide the reader in selecting such as shall be best adapted to his own wants: "For this purpose he has consulted the best European authors, their conclusions being drawn from hundreds of years of laborious investigation of the spas of Germany, France, Switzerland, and Italy. It has been interesting, in the course of this study, to note how closely the conclusions drawn by them, concerning the action of different classes of waters, agree with the observations made at springs in this country independent of any knowledge of foreign research. The portion relating to the springs of the United States is the result of a selection of credible evidence regarding them gained by correspondence and personal observation."
After some preliminary chapters on the nature, classification, and chemical constituents of mineral waters and their relations to various organs and diseases, Dr. Walton considers the springs of the country under the heads of "Saline Waters," "Sulphur Waters," "Chalybeate Waters," "Purgative Waters," "Calcic Waters," and "Thermal Waters," and the resources of the whole country are then given in respect to mineral waters having these various properties. Of all the localities in the United States or Canada, Saratoga is the most eminent for the extent and variety of
