POPULAR SCIENCE MONTHLY.
various creatures which the previous chapters have thus studied. The book is well printed and illustrated, and, while there are some lapses into technical phraseology, the text is in the main readily comprehensible by a child of ten or twelve.
A work by Dr. C. Christiansen, of Copenhagen, on the Elements of Theoretical Physics, has been translated by Prof. W. F. Magie, of Princeton (Macmillan, $3.25). Although with ill-judged modesty labeled "Elements," it is an advanced text-book presenting the mathematical side of the subject exclusively and using the calculus throughout. The translator deems it valuable because it presents the fundamental principle of theoretical physics, and develops them so far as to bring the reader in touch with much of the new work that is being done in the subject. While not in every respect exhaustive, he regards it as stimulating and informing, and as furnishing a view of the whole field that will facilitate the reader's progress in special parts of it. He says further that there has been a need of such a book in which the various branches of the subject are developed in connection with one another and in a consistent notation.
The lectures delivered at the Princeton sesquitennial celebration by Prof. A. A. W. Hubrecht on The Descent of the Primates have reached us in book form (Scribner's, $1). While the subject is a highly technical one, and the treatment is necessarily such as to place the argument beyond the reach of any one but a specialist, the investigation has so important a bearing on the evolutional origin of the human race that it has been deemed worthy of permanent form. The contention is, briefly, that the usual way of looking upon the three subdivisions—the duckbills, the marsupials, and the placental mammals—as a real and historical sequence is not in accordance with their true relationships. This is not, as the author says, a new idea, but was originated some years ago by Huxley. The author has derived his material chiefly from a study of the embryology of the tarsius, a curious and rare form hitherto ranked with the lemuroids.
The Mechanical Arts Simplified, by D. B. Dixon (Laird & Lee, Chicago), is one of those so-called handbooks of useful information. It seems to contain a great deal of accurate information, in the shape of tables and formulæ, for the mechanic and the mechanical engineer, but it is largely a compilation of unrelated and isolated facts which have little practical value for the average mechanic, and which are of slight value, at best, in such a book, because of the difficulty of finding them. For instance, on page 258 we have first a table giving the weights of thirteen metals, followed by some tables on flour and corn mills extending through page 259; page 260 discusses the miner's inch and the flow of water through vertical rectangular openings, and page 261 gives us, among other things, a table of mortality statistics based on American experience, the date when the first steamboat plied the Hudson, when the first sawmaker's anvil was brought to America, when kerosene was first used for lighting purposes, when the first lucifer match was made, and the date of the appearance of the first newspaper advertisement.
A list of Reagents and Reactions known by the Names of their Authors, based on the collection of A. Schneider, has been issued by the Pharmaceutical Review Publishing Company, of Milwaukee. It is of interest chiefly to pharmacists and analysts (price, 50 cents).
A little volume on Les Insectes nuisibles, by A. Acloque, that has recently come to us is devoted to giving the habits and mode of development of noxious insects, and the best known means of combating these creatures. The book contains sixty-seven cuts. (F. Alcan, Paris, paper, 60 centimes; cloth, 1 fr.)
In English Local Government of To-day (Vol. IX, No. 1, Columbia Studies in Economics) M. R. Maltbie gives us a careful economic discussion of the relations between central and local government. The purposes of the inquiry are thus set forth in the introduction: "First, to show the growth and historical development of the English system of central and administrative control; second, to outline its present legal and practical status; and, third, to ascertain the actual results obtained through it." The author arrives at the conclusion that local self-government, pure and simple, has been proved inefficient, and that it is possible to estab-