Page:Popular Science Monthly Volume 20.djvu/139

Rh "The Tonicity of the Heart and Blood Vessels"; and the articles in number II, "On the Proteid Substances contained in the Seeds of Plants," "The Influence of Season and of Temperature on the Action and the Antagonisms of Drugs," and "The Elastic Properties of the Arterial Wall," are especially noteworthy, and their conclusions of much scientific interest. The supplement gives an extensive list of titles of books and papers upon physiological questions, in all the modern languages, that have appeared in 1880. Six numbers form a volume of about 500 pages, the American subscription of which is $5, and may be remitted to Mr. W. T. Sedgwick, Johns Hopkins University, Baltimore, Maryland. The American edition of the Journal now appears under the auspices of that institution.

no field has modern research been more fruitful than in that of which Professor Judd gives a popular account in the present volume. The great lines of dynamical, geological, and meteorological inquiry converge upon the grand problem of the interior constitution of the earth, and the vast influence of subterranean agencies. The subject was first comprehensively dealt with in the light of modern scientific views by the late Mr. Poulett Scrope, who published two systematic treatises upon different divisions of it in the years 1825 and 1827. Professor Judd was a student and disciple of this master, who, before he died, committed to him the task of preparing a popular exposition of the present condition of our knowledge on volcanoes. Since the time of Scrope's pubiicationpublication [sic] many important additions have been made to the subject, and these the author has faithfully incorporated in the book now issued. The plan and spirit of the work are thus indicated in his preface:

"In order to keep the work within the prescribed limits, and to avoid unnecessary repetitions, I have confined myself to the examination of such selected examples of volcanoes as could be shown to be really typical of all the various classes which exist upon the globe; and I have endeavored from the study of these to deduce those general laws which appear to govern volcanic action. But it has, at the same time, been my aim to approach the question from a somewhat new standpoint, and to give an account of those investigations which have in recent times thrown so much fresh light upon the whole problem. In this way I have been led to dwell at some length upon subjects which might not at first sight appear to be germane to the question under discussion—such as the characters of lavas revealed to us by microscopic examination; the nature and movements of the liquids inclosed in the crystals of igneous rocks; the relations of minerals occurring in some volcanic products to those found in meteorites; the nature and origin of the remarkable iron-masses found at Ovifak in Greenland; and the indications which have been discovered of analogies between the composition and dynamics of our earth and those of other members of the family of worlds to which it belongs. While not evading the discussion of theoretical questions, I have endeavored to keep such discussions in strict subordination to that presentation of the results attained by observation and experiment, which constitutes the principal object of the work."

We are not acquainted with any other work of Professor Judd, but he is an experienced and very agreeable writer, and is evidently a master of the art of statement. His book is very far from being a mere dry description of volcanoes and their eruptions; it is rather a presentation of the terrestrial facts and laws with which volcanic phenomena are associated. We give an extract in our editorial pages which well represents the quality of the book. The illustrations are numerous, well chosen, and especially fine in execution; and the volume is among the best of the series to which it belongs.

book is an example on a small scale of the common remark that "history