Page:Popular Science Monthly Volume 44.djvu/722

706 the whole ground, which most schoolbook writers cling to, and aims chiefly to impress the principles of the science upon the pupil's mind. Enough descriptive matter is used to illustrate these principles, but not so much as to obscure the main purpose of the book.

usual books on this and kindred subjects are either so technical as to be incomprehensible to the general reader, or so popular as to be of no considerable value to any one. Mr. Cooke has attempted to strike a happy medium, and while giving the mechanical construction and action of locomotives, accurately and in detail, he does so in untechnical language, and assists his text with carefully prepared drawings and diagrams. An idea of the scope of the work may be gathered from some of the chapter headings: Early History; Action of the Steam in the Cylinder; Valve Motion; The Boiler; General Details; How an Engine is put together; Classification of Engines; Brakes; Compound Locomotives; Combustion and Consumption of Fuel, and Engine Drivers and their Duties. The book is nicely printed and fully illustrated.

book belongs to the series of Introductory Science Text-books which this firm is now publishing, and is one of its most important volumes. The subject is one about which students should have something more than vague ideas; and yet, unfortunately, this is about the extent of their ordinary biological knowledge at the time of graduation. Biology lies at the root of human physiology, and this in turn should dictate that self-care and self-preservation upon which all our other actions in life depend. The scheme of the book is, first, a discourse on living as distinguished from non-living matter; followed by an examination into the properties and characteristics of protoplasm. Then the cell in its various forms, followed by a chapter on embryology. The tissues, both animal and vegetable, are next discussed; and finally there are several pages pointing out the differences between plants and animals, which sum up as follows:

"We have thus seen that there is no single attribute of animals which is not shared by some plants; and, on the other hand, there is no plant characteristic which is possessed by plants alone; hence it is necessary to allow that plants and animals are fundamentally identical, and, in fact, are only divisions of a single vital stock." An elementary examination follows of the forms of life usually considered in introductory text-books—the amœba, yeast plant, vorticella, tapeworm, leech, etc.

Dr. Campbell has given us a work well suited to beginners, and hence an important addition to our text-books on the subject. The book is well printed and illustrated.

have in this volume a substantial contribution to the literature of its subject. It consists of two parts, the first being a presentation of the most prominent systems of evolutionary ethics, under the names of their respective propounders, while the second is a general examination of the whole field. The authors whose views are set forth are Darwin, Wallace, Haeckel, Spencer, Fiske, Rolph, Barratt, Stephen, Carneri, Höffding, Gizycki, Alexander, and Ree. Mr. Williams must be a hero-worshiper who sees all wisdom in Darwin, else he would not have lugged in the great biologist's name at the head of this list. He calls Darwin "the first laborer in this line," and says that "a review of evolutional ethics must, therefore, in order to start with the proper origin of the science, begin with Charles Darwin." He gets together ten pages of extracts from Darwin's works, the first four pages of which relate to nothing but instinct and heredity. These are from the Origin of Species, which appeared in 1869, and the essay on Instinct prepared for that work, but not published till after Darwin's death. Then follow quotations from the Descent of Man, some of which do relate to ethics, but the date when