"Of Ether-Waves" is the heading under which the phenomena of radiation, including reflection, refraction, and interference, are treated. In defining electricity and magnetism, the author states that they "are not forms of energy; neither are they forms of matter. They may, perhaps, be provisionally defined as properties or conditions of matter; but whether this matter be the ordinary matter, or whether it be, on the other hand, that all-pervading ether by which ordinary matter is everywhere surrounded, is a question which has been under discussion, and which may now be fairly held to be settled in favor of the latter view." Although the author, in his preface to this solid volume, expresses the modest hope that it may "be found fitted to serve as an elementary introduction" to a course of wider reading and practical study, it is by no means a book for immature students. It is illustrated with about two hundred and fifty diagrams.
The Relation of Animal Diseases to the Public Health. By Frank S. Billings, D. Y. S., etc. New York: D. Appleton & Co. Pp. 446. Price, $4.
The subject considered in this volume is one of great practical importance both to individuals and to the community at large. The author is a veterinary surgeon of eminent standing, a graduate of the Royal Veterinary Institute of Berlin, and honored by various kindred institutions and societies. In addition to the qualifications thus attested. Dr. Billings has another excellent requisite for the task he has undertaken, which is deep feeling upon the subject—an interest inspired of large knowledge—in fact, an intense enthusiasm well suited to the kind of work he has in hand. He writes with vigor, and often with a vehemence that might involve exaggerated statement; but we must remember that his work is not a treatise on veterinary practice, or a manual of medical and surgical treatment of diseased animals, addressed to the profession. It is a work on the prevention of disease, addressed to the general intelligence of the community, and designed to draw attention to questions and to stir up a popular interest in them that shall lead to private and public action, and for this purpose strong language is entirely justifiable. His subject, moreover, is one upon which there is not only much ignorance among otherwise well-informed people, but upon which there is also a great deal of narrow and unworthy prejudice, deserving of unsparing exposure and severe denunciation.
The work is divided into three parts. The first, of 208 pages, is devoted to "The Diseases of Domestic Animals"; Part II, of 155 pages, describes the "History of Veterinary Medicine" and the establishment of veterinary schools; Part III, of 51 pages, treats of "The Means of Prevention" by veterinary schools and institutes and a veterinary police system in the United States. The first part is taken up with a consideration of some of the most important infectious and contagious diseases of animals—those which require both scientific knowledge and official authority for examination and repression. An intelligent writer in "The Journal of Comparative Medicine and Surgery" thus refers to the subjects here discussed:
