Page:Popular Science Monthly Volume 18.djvu/435

Rh not before observed in popular skin treatises, and which gives it a special claim upon intelligent readers. It is not only a guide for the preservation of the health of the skin, but it is a kind of medical dictionary on the subject, giving important information which kindred books omit. This feature of the work is thus explained in the author's prefatory note: "He has therefore sought to introduce in its pages not only the medical terms used in reference to diseases of the skin, but also the popular names given, both those which are rightly and those which are wrongly applied. If, therefore, information be sought in reference to any particular matter, it will be well first to consult the index, which has been made particularly full."

elaborate work will prove most acceptable to the interested students of physiological and medical chemistry. The activity of research in these departments is very great; thoroughly equipped experimental laboratories are multiplying in different countries, and trained men are concentrating their efforts more and more upon special lines of inquiry. The consequence is, a rapid revision of former results, an extension of observations, and a noteworthy physiological progress. Dr. Gamgee's book is written from the point of view, not of former text-books, but of the latest original memoirs, which are continually referred to, and from the point of view of his own varied and laborious experimental investigations. The volume forms a complete and independent work, though it is intended to be followed by another within a year. It is devoted mainly to the elementary tissues or substances of the body—blood, lymph, and chyle being included in the classification—and it deals with the chemical composition, changes, and processes of these parts. The second volume will treat of the chemistry of the chief animal functions. In the method of the work physiological chemistry has been regarded from the point of view of the biologist and the physician rather than from that of the chemist. In this respect the book deviates widely from the typical plan of works on organic chemistry, where the dominant and classifying conceptions are of the chemical order. The volume will meet a want and be much appreciated as a high-class text-book, and it may be safely consulted by all interested in fundamental chemico-physiological questions.

all sciences that of electricity is perhaps the most purely experimental. The agency has always to be evoked by special manipulation. While the properties of heat have always been more or less known to everybody, nothing was known of electricity for thousands of years. It was a revelation that followed the art of experimenting, and it has advanced at a rate exactly proportioned to the progress of experimental art.

Mr. Gordon in this new work has dealt with the science entirely from this side, limiting his use of mathematics, except in a few foot-notes and appendices, to simple algebraic operations. The work is issued in two beautifully printed volumes, which are profusely illustrated with finely executed engravings, representing the present perfection of electrical apparatus and the refinements of electrical processes, and, besides a clear and concise statement of the main facts of the science, contains an exposition of many of the more recent and important experimental researches.

The author claims that he has aimed throughout to interpret the various phenomena in accordance with the theory worked out mathematically by Maxwell and others, which regards inductive influence as transmitted by strain or vibrations of some kind in the intervening medium, instead of being a direct "action at a distance." In accordance with this purpose, most of the later researches to which attention is particularly given, are those which directly bear upon problems the solution of which will throw light upon what may be termed the mechanism of electrical action. Though not